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70. Livestock Rearing

Chapter Editor: Melvin L. Myers


Table of Contents

Tables and Figures

Livestock Rearing: Its Extent and Health Effects
Melvin L. Myers

Health Problems and Disease Patterns
Kendall Thu, Craig Zwerling and Kelley Donham

     Case Study: Arthopod-related Occupational Health Problems
     Donald Barnard

Forage Crops
Lorann Stallones

Livestock Confinement
Kelley Donham

Animal Husbandry
Dean T. Stueland and Paul D. Gunderson

     Case Study: Animal Behaviour
     David L. Hard

Manure and Waste Handling
William Popendorf

     A Checklist for Livestock Rearing Safety Practice
     Melvin L. Myers

Dairy
John May

Cattle, Sheep and Goats
Melvin L. Myers

Pigs
Melvin L. Myers

Poultry and Egg Production
Steven W. Lenhart

     Case Study: Poultry Catching, Live Hauling and Processing
     Tony Ashdown

Horses and Other Equines
Lynn Barroby

     Case Study: Elephants
     Melvin L. Myers

Draught Animals in Asia
D.D. Joshi

Bull Raising
David L. Hard

Pet, Furbearer and Laboratory Animal Production
Christian E. Newcomer

Fish Farming and Aquaculture
George A. Conway and Ray RaLonde

Beekeeping, Insect Raising and Silk Production
Melvin L. Myers and Donald Barnard

Tables

Click a link below to view table in article context.

1. Livestock uses
2. International livestock production (1,000 tonnes)
3. Annual US livestock faeces & urine production
4. Types of human health problems associated with livestock
5. Primary zoonoses by world region
6. Different occupations & health & safety
7. Potential arthropod hazards in the workplace
8. Normal & allergic reactions to insect sting
9. Compounds identified in swine confinement
10. Ambient levels of various gases in swine confinement
11. Respiratory diseases associated with swine production
12. Zoonotic diseases of livestock handlers
13. Physical properties of manure
14. Some important toxicologic benchmarks for hydrogen sulphide
15. Some safety procedures related to manure spreaders
16. Types of ruminants domesticated as livestock
17. Livestock rearing processes & potential hazards
18. Respiratory illnesses from exposures on livestock farms
19. Zoonoses associated with horses
20. Normal draught power of various animals

Figures

Point to a thumbnail to see figure caption, click to see figure in article context.

LIV010F2LIV010T3LIV140F1LIV110F1LIV140F1LIV070F2LIV090F1LIV090F2LIV090F3LIV090F4LIV090F6


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Some information on the silk industry was adapted from the article by J. Kubota in the 3rd edition of this Encyclopaedia.

More than a million species of insects exist in the world, and the global mass of insects exceeds the total mass of all other terrestrial animals. Insects such as crickets, grasshoppers, locusts, termites, beetle larvae, wasps, bees and moth caterpillars are among about 500 species that form part of the regular diet of people around the world. Usually humans hunt or gather insects for food rather than intentionally rearing and harvesting them.

In addition to food, humans use insects as sources of pollination, biological controls of pests and fibre. Different uses depend on the four stages of the insect’s life cycle, which consist of egg, larva, pupa and adult. Examples of commercial uses of insects include beekeeping (nearly 1 billion tonnes of honey produced annually and pollination of fruit and seed crops), insect rearing (more than 500 species in culture, including those used for insect biological control), shellac production (36,000 tonnes annually) and silk production (180,000 tonnes annually).

Beekeeping

Beekeepers raise the honey-bee in apiaries, a collection of hives that house bee colonies. The honey-bee is a source of flower pollination, honey and wax. Bees are important pollinators, making more than 46,430 foraging trips per bee for each kilogram of honey that they produce. During each foraging trip, the honey-bee will visit 500 flowers within a 25-minute period. The honey-bee’s source of honey is flower nectar. The bee uses the enzyme invertase to convert sucrose in the nectar into glucose and fructose and, with water evaporation, honey is produced. In addition, bumble-bees and cutter bees are grown for pollinating, respectively, tomato plants and alfalfa.

The honey-bee colony collects around a single queen bee, and they will colonize in boxes—artificial hives. Beekeepers establish an infant colony of about 10,000 bees in the bottom box of the hive, called a brood chamber. Each chamber contains ten panels with cells that are used for either storing honey or laying eggs. The queen lays about 1,500 eggs per day. The beekeeper then adds a food chamber super (a box placed on top of the brood box), which becomes the storage chamber for honey, on which the bees will survive through the winter. The colony continues to multiply, becoming mature at about 60,000 bees. The beekeeper adds a queen excluder (a flat panel that the larger queen cannot enter) on top of the food super to prevent the queen from laying eggs in additional shallow supers that will be stacked on top of the excluder. These additional supers are designed for harvesting only honey without the eggs.

The beekeeper moves the hives to where flowers are budding. A honey-bee colony can forage over an area of 48 hectares, and 1 hectare can support about two hives. The honey is harvested during the summer from the shallow supers, which can be stacked seven high as the colony grows and the bees fill the panels with honey. The supers with honey-laden panels are transported to the honey “house” for extraction. A sharp, warm knife, called an uncapping knife, is used to remove the wax caps that the bees have placed over the honeycombs within the panels. The honey is then extracted from the panels with a centrifugal force machine. The honey is collected and bottled for sale (Vivian 1986).

At the end of the season, the beekeeper winterizes the hives, wrapping them in tar paper to protect the colonies from the winter wind and to absorb the solar heat. The beekeeper also provides the bees with medicated sugar syrup for their winter consumption. In the spring, the hives are opened to begin production as mature honeybee colonies. If the colony becomes crowded, the colony will create another queen through special feeding, and the old queen will swarm with about half of the colony to find another accommodation. The beekeeper may capture the swarm and treat it as an infant colony.

Beekeepers are exposed to two related hazards from honey-bee stings. One hazard is sting envenomation. The other is venom hypersensitivity reaction and possible anaphylactic shock. Males at 40 years of age and older are at highest risk of fatal reactions. About 2% of the general population is thought to be allergic to venom, but systemic reactions in beekeepers and their immediate family members are estimated at 8.9%. The reaction incidence varies inversely to the numbers of stings received. Anaphylactic reactions to bumble-bee venom are rare except among bumble bee keepers, and their risk is greater if they have been sensitized to honey bee venom.

If a honey-bee stings the beekeeper, the stinger should be removed, and the sting site should be washed. Ice or a paste of baking soda and water should be applied to the site of envenomation. The victim should be watched for signs of systemic reaction, which can be a medical emergency. For anaphylactic reactions, epinephrine is administered subcutaneously at the first sign of symptoms. To assure safe beekeeping, the beekeeper should use smoke at the beehive to neutralize the bees’ protective behaviour and should wear a protective hood and veil, thin gloves and log sleeves or coveralls. Bees are attracted to sweat for the moisture, so beekeepers should not wear watch bands or belts where sweat collects. In extracting the honey, the beekeeper should keep his or her thumb and fingers clear of the cutting motion of the uncapping knife.

Mass Insect Raising

More than 500 species of arthropods are reared in the laboratory, including ants, beetles, mites, flies, moths, spiders and ticks. An important use of these arthropods is as biological controls for other animal species. For example, 2,000 years ago, markets in China sold nests of weaver ants to place in citrus orchards to prey on crop pests. Today, more than 5,000 species of insects have been identified worldwide as possible biological controls for crop pests, and 300 are successfully used regularly in 60 countries. Disease vectors have also become targets for biological control. As an example, the carnivorous mosquito from Southeast Asia, Toxorhynchites spp., also called the “tox” mosquito, has a larva that feeds on the larvae of the tiger mosquito, Aedesspp., which transmits diseases such as dengue fever to humans (O’Toole 1995).

Mass rearing facilities have been developed to raise sterile insects as a non-chemical pest-suppression tool. One such facility in Egypt rears a billion fruit flies (about 7 tonnes) each week. This rearing industry has two major cycles. One is the feed conversion or larval incubation cycle, and the other is the propagation or egg-production cycle. The sterile insect technique was first used to eliminate the screw worm, which preyed on cattle. Sterilization is accomplished by irradiating the pupae just prior to adult emergence from the cocoon with either x rays or gamma rays. This technique takes mass quantities of reared, sterile insects and releases them into infested areas where the sterile males mate with the wild, fertile females. Breaking the insect’s life cycle has dramatically reduced the fertility rate of these pests. This technique is used on screw worms, gypsy moths, boll weevils and fruit flies (Kok, Lomaliza and Shivhara 1988).

A typical sterile insect facility has an airlock system to restrict unwanted insect entry and fertile insect escape. Rearing tasks include mopping and sweeping, egg stacking, tray washing, diet preparation, inoculation (placing eggs into agar), pupae dyeing, emergence tending, packing, quarantining, irradiating, screening and weighing. In the pupae room, vermiculite is mixed with water and placed in trays. The trays are stacked, and the vermiculite dust is swept with a broom. The pupae are separated from the vermiculite with a sieve. The insect pupae chosen for the sterile insect technique are transported in trays stacked on racks to the irradiation chamber in a different area or facility, where they are irradiated and rendered sterile (Froehlich 1995; Kiefer 1996).

Insect workers, including silkworm workers, may have an allergic reaction to arthropod allergens (scales, hairs, other body parts). Initial symptoms are itchy eyes and irritation of the nose followed by intermittent episodes of wheezing, coughing and breathlessness. Subsequent asthma attacks are triggered by re-exposure to the allergen.

Entomologists and workers in sterile fly facilities are exposed to a variety of potentially hazardous, flammable agents. These agents include: in entomology laboratories, isopropyl alcohol, ethyl alcohol and xylene; in the diet preparation room, isopropyl alcohol is used in water solution to sterilize walls and ceilings with a sprayer. Vermiculite dust poses respiratory concerns. Some vermiculites are contaminated with asbestos. Air-handling units in these facilities emit noise that may be damaging to employee hearing. Proper exhaust ventilation and personal respiratory protection can be used in facilities to control exposure to airborne allergens and dusts. Non-dusty working materials should be used. Air conditioning and frequent changes of filters may help reduce airborne levels of spines and hairs. X rays or gamma rays (ionizing radiation) can damage genetic material. Protection is needed against x rays or gamma rays and their sources in the irradiation facilities (Froehlich 1995; Kiefer 1996).

Silkworm Raising

Vermiculture, the raising of worms, has a long history in some cultures. Worms, especially the meal worm (which is a larva rather than a true worm) from the darkling beetle, are raised by the billions as animal fodder for laboratory animals and pets. Worms are also used in composting operations (vermi-composting).

Sericulture is the term used for silkworm cocoon production, which includes silkworm feeding and cocoon formation. Cultivation of the silkworm and the silk moth caterpillar dates back to 3000 BC in China. Silkworm farmers have domesticated the silkworm moth; there are no remaining wild populations. Silkworms eat only white mulberry leaves. Fibre production thus has historically depended upon the leafing season of the mulberry tree. Artificial foods have been developed for the silkworm so that production can extend the year around. Silkworms are raised on trays sometimes mounted on racks. The worms take about 42 days of feeding at a constant temperature of 25 °C. Artificial heating may be required. Silk is a secretion from the silkworm’s mouth that solidifies upon contact with air. The silkworm secretes about 2 km of silk fibre to form a cocoon during the pupal stage (Johnson 1982). After the cocoon is formed, the silkworm farmer kills the pupa in a hot oven, and ships the cocoon to a factory. At the factory, silk is harvested from the cocoon and spun into thread and yarn.

Nine per cent of silkworm workers manifest asthma in response to silkworm moth scales, although most asthma in silkworm workers is attributed to inhalation of silkworm faeces. In addition, contact of the skin with silkworm caterpillar hairs may produce a primary irritant contact-dermatitis. Contact with raw silk may also produce allergic skin reactions. For silk moth production, hyposensitization therapy (for moth scales and faeces) provides improvement for 79.4% of recipients. Corticosteroids may reverse the effects of inhaled antigens. Skin lesions may respond to topical corticosteroid lotions and creams. Oral antihistamines relieve itching and burning. Carbon monoxide poisoning has been identified among some silkworm farmers in their homes, where they are maintaining warmth with charcoal fires as they raise the silkworms. Charcoal fires and kerosene heaters should be replaced with electric heaters to avoid carbon monoxide exposures.

 

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Monday, 28 March 2011 19:46

Fish Farming and Aquaculture

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Background

Rearing marine organisms for food has been a widespread practice since ancient times. However, large-scale farming of molluscs, crustaceans and bony fishes has rapidly gained momentum since the early 1980s, with 20% of the world’s seafood harvest now farmed; this is projected to increase to 25% by 2000 (Douglas 1995; Crowley 1995). Expansion of world markets contemporaneous with depletion of wild stocks has resulted in very rapid growth of this industry.

Land-based aquaculture takes place in tanks and ponds, while water-based culture systems generally employ screened cages or moored net pens of widely varying designs (Kuo and Beveridge 1990) in salt water (mariculture) or fresh rivers.

Aquaculture is performed as either an extensive or intensive practice. Extensive aquaculture entails some form of environmental enhancement for naturally produced species of fish, shellfish or aquatic plants. An example of such a practice would be laying down oyster shells to be used as attachment substrate for juvenile oysters. Intensive aquaculture incorporates more complex technology and capital investment in the culture of aquatic organisms. A salmon hatchery that uses concrete tanks supplied with water via some delivery system is an example. Intensive aquaculture also requires greater allocation of labour in the operation.

The process of intensive aquaculture includes the acquisition of broodstock adults used for production of gametes, gamete collection and fertilization, incubation of eggs and juvenile rearing; it may include rearing of adults to market size or release of the organism into the environment. Herein lies the difference between farming and enhancement aquaculture. Farming means rearing the organism to market size, generally in an enclosed system. Aquaculture for enhancement requires the release of the organism into the natural environment to be harvested at a later date. The essential role of enhancement is to produce a specific organism as a supplement to natural production, not as a replacement. Aquaculture can also be in the form of mitigation for loss of natural production caused by a natural or human-made event—for example, construction of a salmon hatchery to replace lost natural production caused by the damming of a stream for hydroelectric power production.

Aquaculture can occur in land-based facilities, on-bottom marine and freshwater environments and floating structures. Floating net pens are used for fish farming, and cages suspended from raft or buoy flotation are commonly used for shellfish culture.

Land-based operations require the construction of dams and/or excavation of holes for ponds and raceways for water flushing. Mariculture can involve the construction and maintenance of complex structures in harsh environments. Handling of smolt (for bony fishes) or tiny invertebrates, feed, chemical treatments for water and the animals being raised and wastes have all evolved into highly specialized activities as the industry has developed.

Hazards and Controls

Injuries

Fish farming operations afford many injury risks, combining some of those common to all modern agriculture operations (e.g., entanglement in large machinery, hearing loss from prolonged exposure to loud engines) with some hazards unique to these operations. Slips and falls can have particularly bad outcomes if they occur near raceways or pens, as there are the dual added risks of drowning and biological or chemical contamination from polluted water.

Severe lacerations and even amputations may take place during roe-stripping, fish butchering and mollusc shelling and can be prevented by the use of guards, protective gloves and equipment designed specifically for each task. Lacerations contaminated by fish slime and blood can cause serious local and even systemic infections (“fish poisoning”). Prompt disinfection and debridement is essential for these injuries.

Electrofishing (used to stun fish during survey counts, and increasingly in collection of broodstock at hatcheries) carries a high potential for electrical shock to the operators and bystanders (National Safety Council 1985) and should be done only by trained operators, with personnel trained in cardiopulmonary resuscitation (CPR) on site. Only equipment specifically designed for electrofishing operations in water should be employed and scrupulous attention must be paid to establishing and maintaining good insulation and grounding.

All water poses drowning risks, while cold waters pose the additional hazard of hypothermia. Accidental immersions due to falls overboard must be guarded against, as must potential for ensnarement or entrapment in nets. Approved personal flotation devices should be worn by all workers at all times on or near the water, and some thermal protection should also be worn when working around cold waters (Lincoln and Klatt 1994). Mariculture personnel should be trained in marine survival and rescue techniques, as well as CPR.

Repetitive strain injuries may also occur in butchering and hand-feeding operations and can be largely avoided by attention to ergonomics (via task analysis and equipment modifications as necessary) and frequent task rotations of manual workers. Those workers developing repetitive strain injury symptoms should receive prompt evaluation and treatment and possible reassignment.

Sleep deprivation can be a risk factor for injuries in aquaculture facilities requiring intensive labour over a short duration of time (e.g., egg harvest at salmon hatcheries).

Health hazards

Diving is frequently required in construction and maintenance of fishpens. Predictably, decompression illness (“bends”) has been observed among divers not carefully observing depth/time limits (“dive tables”). There have also been reports of decompression illness occurring in divers observing these limits but making many repetitive short dives; alternative methods (not using divers) should be developed for clearing dead fish from and maintaining pens (Douglas and Milne 1991). When diving is deemed necessary, observing published dive tables, avoiding repetitive dives, always diving with a second diver (“buddy diving”) and rapid evaluation of decompression-like illnesses for possible hyperbaric oxygen therapy should be regular practices.

Severe organophosphate poisoning has occurred in workers incidental to pesticidal treatment of sea lice on salmon (Douglas 1995). Algicides deployed to control blooms may be toxic to workers, and toxic marine and freshwater algae themselves may afford worker hazards (Baxter 1991). Bath treatments for fungal infections in fish may use formaldehyde and other toxic agents (Douglas 1995). Workers must receive adequate instruction and allotment of time for safe handling of all agricultural chemicals and hygienic practices around contaminated waters.

Respiratory illnesses ranging from rhinitis to severe bronchospasm (asthma-like symptoms) have occurred due to sensitization to putative endotoxins of gram-negative bacteria contaminating farmed trout during gutting operations (Sherson, Hansen and Sigsgaard 1989), and respiratory sensitization may occur to antibiotics in medicated fish feeds. Careful attention to personal cleanliness, keeping seafood clean during butchering and handling and respiratory protection will help ensure against these problems. Workers developing sensitivity should avoid subsequent exposures to the implicated antigens. Constant immersion of hands can facilitate dermal sensitization to agricultural chemicals and foreign (fish) proteins. Hygienic practice and use of task-appropriate gloves (such as cuffed, insulated, waterproof neoprene during cold butchering operations) will reduce this risk.

Sunburn and keratotic (chronic) skin injury may result from exposure to sunlight. Wearing hats, adequate clothing and sunscreen should be de rigueur for all outdoor agricultural workers.

Large quantities of stored fish feeds are often raided by or infested with rats and other rodents, posing a risk for leptospirosis (Weil’s disease). Workers handling fish feeds must be vigilant about feed storage and rodent control and protect abraded skin and mucous membranes from contact with potentially contaminated feeds and soiled pond waters. Feeds with known contamination with rat urine should be handled as potentially infectious, and discarded promptly (Ferguson and Path 1993; Benenson 1995; Robertson et al. 1981).

Eczema and dermatitis can easily evolve from inflammation of skin macerated by constant water contact. Also, this inflammation and wet conditions can foster reproduction of human papillaviridae, leading to rapid spread of skin warts (Verruca vulgaris). Prevention is best accomplished by keeping hands as dry as possible and using appropriate gloves. Emollients are of some value in the management of minor skin irritation from water contact, but topical treatment with corticosteroids or antibiotic creams (after evaluation by a physician) may be necessary if initial treatment is unsuccessful.

Environmental Impacts

Demand for fresh water can be extremely high in all of these systems, with estimates centring on 40,000 litres required for each 0.5 kg of bony fish raised to maturity (Crowley 1995). Recirculation with filtration can greatly reduce demand, but requires intensive application of new technologies (e.g., zeolites to attract ammonia).

Fish farm discharges can include as much faecal waste as that from small cities, and regulations are rapidly proliferating for control of these discharges (Crowley 1995).

Consumption of plankton and krill, and side effects of mariculture such as algal blooms, can lead to major disruptions in species balance in the local ecosystems surrounding fish farms.

 

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Processes

Institutional animal programmes involve four major processes:

  1. receipt, quarantine and separation of animals
  2. separation of species or animals for individual projects when necessary
  3. housing, care and sanitation
  4. storage.

 

Husbandry tasks include feeding, watering, providing bedding, maintaining sanitation, disposing of waste including carcasses, controlling pests and veterinarian care. Materials handling is significant in most of these tasks, which include moving cages, feed, pharmaceuticals, biologics and other supplies. Handling and manipulating animals is also fundamental to this work. Sanitation involves changing bedding, cleaning and disinfecting, and cage washing is a significant sanitation task.

Institutional animal facilities include cages, hutches, pens or stalls within a room, barn or outdoor habitat. Adequate space, temperature, humidity, food and water, illumination, noise control and ventilation are provided in a modern facility. The facility is designed for the type of animal that is confined. Animals that are typically confined in institutional settings include group-housed rodents (mice, rats, hamsters and guinea pigs), rabbits, cats, dogs, mink, non-human primates (monkeys, baboons and apes), birds (pigeons, quail and chickens) and farm animals (sheep and goats, swine, cattle, horses and ponies).

Hazards and Precautions

Persons involved with the production, care and handling of pet, furbearer and laboratory animals are potentially exposed to a variety of biological, physical and chemical hazards that can be controlled effectively through available risk reduction practices. The biological hazards intrinsic to the various animal species of concern to personnel include: bites and scratches; highly sensitizing allergens in dander, serum, tissues, urine or salivary secretions; and a wide variety of zoonotic agents. Although the biological hazards are more diverse and potentially more devastating in the work environments supporting these types of animals, the physical and chemical hazards generally are more pervasive, as reflected by their contribution to illness and injury in the workplace.

Personnel involved in the care and production of pet, furbearer or laboratory animals should receive appropriate training in handling techniques and behaviour of the animal species in question, because incorrect handling of an intractable animal frequently is a precipitating cause of a bite or scratch. Such injuries can become contaminated with micro-organisms from the animal’s rich oral and skin microflora or the environment, necessitating immediate wound disinfection and prompt and aggressive antimicrobial therapy and tetanus prophylaxis to avert the serious complications of wound infection and disfigurement. Personnel should appreciate that some zoonotic bite infections can produce generalized disease and even death; examples of the former include cat scratch fever, rat bite fever and human orf infection; examples of the latter include rabies, B virus and hantavirus infection.

Due to these extraordinary risks, wire-mesh, bite-proof gloves can be beneficial in some circumstances, and the chemical restraint of animals to facilitate safe handling is sometimes warranted. Personnel also can contract zoonoses through the inhalation of infectious aerosols, contact of the organisms with the skin or mucous membranes, ingestion of infectious materials or transmission by specific fleas, ticks or mites associated with the animals.

All types of zoonotic agents occur within pet, furbearer and laboratory animals, including viruses, bacteria, fungi and internal and external parasites. Some examples of zoonoses include: giardiasis and campylobacterosis from pets; anthrax, tularaemia and ringworm from furbearers; and lymphocytic choriomeningitis, hantavirus and dwarf tapeworm infestation from the laboratory rodent. The distribution of zoonotic agents varies widely according to host animal species, location and isolation from other disease reservoirs, housing and husbandry methods, and history and intensity of veterinary care. For example, some of the commercially produced laboratory animal populations have undergone extensive disease eradication programmes and been maintained subsequently under strict quality control conditions precluding the reintroduction of diseases. However, comparable measures have not been applicable universally in the various settings for pet, furbearer and laboratory animal maintenance and production, enabling the persistence of zoonoses in some circumstances.

Allergic reactions, ranging from ocular and nasal irritation and drainage to asthma or manifesting on the skin as contact urticaria (“hives”), are common in individuals who work with laboratory rodents, rabbits, cats and other animal species. An estimated 10 to 30% of individuals working with these animal species eventually develop allergic reactions, and persons with pre-existing allergic disease from other agents are at higher risk and have an increased incidence of asthma. In rare circumstances, such as a massive exposure to the inciting allergen through an animal bite, susceptible persons can develop anaphylaxis, a potentially life-threatening generalized allergic reaction.

Good personal hygiene practices should be observed by personnel to reduce their likelihood of exposure to zoonoses and allergens during work with animals or animal by-products. These include the use of dedicated work clothing, the availability and use of hand washing and shower facilities and separation of personnel areas from animal housing areas. Work clothing or protective outer garments covering the skin should be worn to prevent exposure to bites, scratches and hazardous microbes and allergens. Personal protective equipment, such as impervious gloves, safety glasses, goggles or other eye protection, and respiratory protection devices (e.g., particle masks, respirators or positive air pressure respirators) appropriate to the potential hazards and the individual’s vulnerability, should be provided and worn to promote safe work conditions. Engineering controls and equipment design also can effectively reduce the exposure of personnel to hazardous allergens and zoonoses through directional air flow and the use of isolation caging systems that partition the workers’ and animals’ environments.

Personnel also encounter significant physical and chemical hazards during animal care. Routine husbandry tasks involve moving or lifting heavy equipment and supplies, and performing repetitive tasks, affording personnel the ubiquitous opportunity to develop cuts and crush injuries, muscular strains and repetitive motion injuries. Work practice redesign, specialized equipment and personnel training in safe work practices can be used to curb these untoward outcomes. Equipment and facility sanitation frequently relies on machinery operating on live steam or extremely hot water, placing personnel at risk of severe thermal injury. The correct design, maintenance and utilization of these devices should be assured to prevent personnel injury and facilitate heat dissipation to provide a comfortable work environment. Personnel who work around large equipment, as well as around rambunctious dog or non-human primate populations, may be exposed to extremely high noise levels, necessitating the use of hearing protection. The various chemicals used for cage and facility sanitation, pest control within the animal facility and external parasite control on animals should be reviewed carefully with personnel to ensure their strict adherence to practices instituted to minimize exposure to these potentially irritating, corrosive or toxic substances.

 

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Monday, 28 March 2011 19:42

Bull Raising

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While the term bull refers to the male of several species of livestock (elephant, water buffalo and cattle) this article will deal specifically with the cattle industry. The National Traumatic Occupational Fatalities (NTOF) surveillance system in the United States, based on death certificates and maintained by the National Institute for Occupational Safety and Health (NIOSH), identified 199 fatalities from 1980 to 1992 associated with the agricultural production industry and inflicted by livestock. Of these, about 46% (92) were directly attributed to beef and dairy bull handling.

Cattle raisers have for centuries used castration of male animals as a means of producing docile males. Castrated males are generally passive, indicating that hormones (largely testosterone) are related to aggressive behaviour. Some cultures place high value on the fighting character of bulls, which is utilized in sports and social events. In this case, certain bloodlines are bred to maintain and enhance these fighting characteristics. In the United States, demand has increased for bulls used in rodeos as these entertainment events have increased in popularity. In Spain, Portugal, parts of France, Mexico and parts of South America, bullfighting has been popular for centuries. (See the article “Bullfighting and rodeos” in the chapter Entertainment and the Arts.)

The cattle industry can be divided into two major categories—dairy and beef—with some dual-purpose breeds. Most commercial beef operations purchase bulls from pure-bred producers, while dairy operations have moved more toward artificial insemination (AI). Thus, the pure-bred producer generally raises the bulls and then sells them when they are of breeding age (2 to 3 years of age). There are three systems of mating currently used in the cattle industry. Pasture mating allows bull to run with the herd and breed cows as they come into oestrus (heat). This can be for the entire year (historically) or for a specific breeding season. If specific breeding seasons are utilized, this necessitates separating the bull from the herd for periods of time. Hand mating keeps the bull isolated from the cows, except when a cow in oestrus is brought to the bull for mating. Generally, only a single mating is allowed, with the cow being removed after service. Finally, AI is the process of using proven sires, through the use of frozen semen, to be bred to many cows by AI technicians or the producer. This has the advantage of not having a bull at the ranch, which is a reduction of risk for the producer. However, there is still potential for human-animal interaction at the point of semen collection.

When a bull is removed from the herd for hand mating or kept isolated from the herd to establish a breeding season, he may become aggressive when he detects a cow in oestrus. Since he cannot respond naturally through mating, this can lead to the “mean bull” complex, which is an example of abnormal behaviour in bulls. Typical antagonistic or combative behaviour of bulls includes pawing the ground and bellowing. Furthermore, disposition often deteriorates with age. Old breeding stock can be cantankerous, deceptive, unpredictable and large enough to be dangerous.

Facilities

To ensure movement of animals through facilities, chutes should be curved so that the end cannot be seen when first entering, and the corral should be designed with a gap to the left or right so that animals do not sense that they are trapped. Putting rubber bumpers on metal items which create a loud noise when they close can help lessen the noise and reduce stress to the animal. Ideally, facilities should maximize the reduction of hazards due to physical contact between the bull and humans through use of barriers, overhead walkways and gates that can be manipulated from outside the enclosure. Animals are less likely to balk in chutes built with solid walls instead of fencing materials, since they would not be distracted by movement outside the chutes. Alleyways and chutes should be large enough so the animals can move through them, but not so wide they can turn around.

Guidelines for Handling

Male animals should be considered potentially dangerous at all times. When bulls are kept for breeding, injuries can be avoided by having adequate bull-confinement and restraint facilities. Extreme caution should be practised when handling male animals. Bulls may not purposefully hurt people, but their size and bulk make them potentially dangerous. All pens, chutes, gates, fences and loading ramps should be strong and work properly. Proper equipment and facilities are necessary to assure safety. Ideally, when working with bulls, having the handler physically separated from contact with the bull (outside the area and protected by chutes, walls, barriers and so on) greatly reduces the risk of injury. When handlers are with the animal, escape passages should be provided to allow handlers to escape from animals in an emergency. Animals should not be prodded when they have no place to go. Handlers should stay clear of animals that are frightened or “spooked” and be extra careful around strange animals. Solid wall chutes, instead of fencing, will lower the number of animals that balk in the chute. Since bulls see colours as different shades of black and white, facilities should be painted all in the same colour. Properly designed treatment stalls and appropriate animal-restraint equipment and facilities can reduce injuries during animal examination, medication, hoof trimming, dehorning and hand mating.

People who work with animals recognize that animals can communicate despite being unable to speak. Handlers should be sensitive to warnings such as raised or pinned ears, raised tail, pawing the ground and bellowing. General information and guidelines for working with bulls are provided in the checklist and article on animal behaviour in this chapter.

Zoonoses

Handlers should also be concerned with zoonotic diseases. A livestock handler can contract zoonotic illnesses by handling an infected animal or animal products (hides), ingesting animal products (milk, undercooked meat) and disposing of infected tissues. Leptospirosis, rabies, brucellosis (undulant fever in humans), salmonellosis and ringworm are especially important. Tuberculosis, anthrax, Q fever and tularaemia are other illness that should be of concern. To reduce exposure to disease, basic hygiene and sanitation practices should be used, which include prompt treatment or proper disposal of infected animals, adequate disposal of infected tissues, proper cleaning of contaminated sites and proper use of personal protective equipment.

The most sanitary method of carcass disposal is burning it at the site of death, to avoid contamination of the surrounding ground. A hole of appropriate size should be dug, flammable materials of sufficient quantity placed inside and the carcass placed on top in order that it can be consumed in its entirety. However, the most common method of carcass disposal is burial. In this procedure, the carcass should be buried at least 4 feet deep and covered with quicklime in soil that is not susceptible to contamination by drainage and away from flowing streams.

 

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Monday, 28 March 2011 19:40

Draught Animals in Asia

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Livestock contributes significantly to the life of small farmers, nomads and foresters all over the world and increases their productivity, income, employment and nutrition. This contribution is expected to rise. The world population will rise from its present 4.8–5.4 billion people to at least 10 billion in the next 100 years. The population of Asia can be expected to double over that same period. The demand for food will rise even more as the standard of living also rises. Along with this will be a rise in the need for draught power to produce the increased food required. According to Ramaswami and Narasimhan (1982), 2 billion people in the developing countries depend on draught animal power for farming and rural transportation. Draught power is critically short at the time of crop planting and is insufficient for other purposes throughout the year. Draught power will remain a major source of energy in agriculture into the foreseeable future, and the lack of draught power in some places may be the primary constraint to increasing crop production.

Animal draught power was the first supplement to human energy inputs in agriculture. Mechanized power has been used in agriculture only in the last century or so. In Asia, a greater proportion of farmers depend on animals for draught power than in any other parts of the world. A large proportion of these animals belong to farmers who have limited resources and cultivate small areas of land. In most parts of Asia, animal power is supplied by bullocks, buffalo and camels. Bullocks will continue to be the common source of farm power, mainly because they are adequate and live on waste residues. Elephants are also used in some places.

Production

In Asian countries, there are three main sources of power used in agriculture: human, mechanical and animal. Human beings provide the main source of power in developing countries for hoeing, weeding, rice transplanting, seed broadcasting and harvesting of crops. Mechanical power with its versatility is used for practically all the field operations, and the intensity of usage varies considerably from one developing country to another (Khan 1983). Animal power is generally used for tillage operations, haulage and operation of some water-lifting devices. A draught cow is a multipurpose farm animal, providing power, milk, dung, calves and meat. Normal draught power of various animals is presented in table 1.

Table 1. Normal draught power of various animals

Animals

Weight (kg)

Approx. draught (kg)

Average speed of work (m/sec)

Power developed (h.p.)

Light horses

400–700

60–80

1.0

1.00

Bullocks

500–900

60–80

0.6–0.85

0.75

Buffaloes

400–900

50–80

0.8–0.90

0.75

Cows

400–600

50–60

0.7

0.45

Mules

350–500

50–60

0.9–1.0

0.70

Donkeys

200–300

30–40

0.7

0.35

Source: FAO 1966.

To have better draught animal power the following aspects should be considered:

For landless people to repay a loan for purchase of bullocks, feed them, and earn sufficient income to meet everyday costs, they must be able to work their animals for six hours per day.

  • Draught animal nutrition. Animal nutrition is a principal factor in increasing the productivity of draught animal power. This is possible only if the necessary feed is available. In some areas, more effort is made to ensure the best use of available resources, such as treating straw with alkali (molasses urea block (MUB)) to improve its nutrient availability. As draught power availability is presently limiting the production of staple crops (there is an estimated 37% deficiency in draught requirements at the time of harvest), a primary objective is to produce draught animals and improve the efficiency of draught power. The opportunity to use improved nutritional technology (e.g., MUB) may assist draught power development through improved animal work capacity and reproduction rates in the female herd as well as better growth of young animals, which will lead to larger body size.
  • Breeding and selection. Culling of local unproductive breed bulls and selection of the best local bull is necessary. Draught animals are currently selected according to their conformation, temperament and health; however, farmers often must rely on what is available locally.

Some crossbreds show a significant increase not only in milk and meat producing capability, but also in draught power. In India, Pakistan and Australia there have been tremendous efforts made in cross-breeding buffalo, cattle, horses (to produce mules) and, in some places, camels. This has produced very encouraging results. In many other Asian countries, especially developing countries, this research work for improving draught power as well as milk and meat production is very much needed.

  • Equipment. Most farm equipment is old and unproductive. Much of the equipment that is used in conjunction with draught animals (harnesses, cultivation tools and carts) is of traditional type, the design of which has not changed for hundreds of years. In addition, farm implements are often badly designed and achieve low work output.
  • Health. The stress of working may upset the balance which often exists between healthy animals and parasites.

 

Management

The daily feeding of draught animals varies according to work season. Both draught cattle and buffalo are fed in confinement (year-round) through a cut and carry system, with little or no grazing. Rice straw is fed all year long, depending on farmer preference, at either a measured rate of 8 to 10 kg per day or as necessary. Other crop residues such as rice hulls, pulse straw and cane tops are fed when available. In addition to these crop residues, cut or grazed green grass from roadsides and embankments is fed during the rainy season (April into November) at the rate of 5 to 7 kg/day and may be increased during times of heavy work to 10 kg/day.

Draught animal feed is usually supplemented with small amounts of by-product concentrates such as brans, oil cakes, pulses, rice hulls and molasses. The predominant means of feeding concentrates to draught animals is in a liquid form with all of the ingredients mixed together. The types and amounts of ingredients vary according to the daily workload of the animal, the geographical area, farmer preference and capability. Increased amounts of concentrates are fed during the heavy work seasons, and they are reduced during the monsoon season, when the workload is light.

Animal feed ingredients are also chosen by farmers based on availability, price, and their perception and understanding of its feeding value. For example, during the work season from November to June, daily rations may be: 200 g of mustard seed oil cake along with 100 g (dry weight) of boiled rice; 3/4 g of mustard seed oil cake, 100 g boiled rice and 3/4 g of molasses; or 2 kg total of equal parts sesame oil cake, rice polish, wheat bran and boiled rice, along with salt. On actual workdays during this period (163 days), animals are fed an extra 50% of these same rations. If animals are fed any concentrates at all during the non-working season, the rate ranges from 1/4 to 1/2 kg.

Draught Power in Australia

The Australian continent was first colonized by Europeans in 1788. Cattle were introduced with the first ships, but escaped into the surrounding forest. During those days ploughing and other land preparation was done with the heavy bullock plough, and light cultivation either with bullocks or horses. The bullock cart became the standard means of land transport in Australia and remained so until road building and railway construction began and became more widespread following the gold rushes from 1851 onwards.

In Australia other draught animals include the camel and the donkey. Although mules were used, they never became popular in Australia (Auty 1983).

Draught Power in Bangladesh

In Bangladesh livestock play a vital role in the economy, providing both draught power and milk and contributing up to 6.5% of the gross domestic product (GDP) (Khan 1983). Out of the 22 million head of cattle, 90% are used for draught power and transportation. Of this total, 8.2 million are dual purpose, supplying both draught power and dairy products, such as milk and meat (although in minimal amounts) for household consumption and trade. Adding energy value from draught power and dung (fertilizer and fuel), livestock contribute an estimated 11.3% to the GDP.

It has been observed that some cows are used for draught purposes, despite problems with fertility and health complications, which result in lower milk production and fewer calvings per lifetime. While cows are not usually worked during lactation, they contribute significantly to the annual supply of draught power in Bangladesh: 2.14 million (31%) adult female cattle and 60,000 (47%) adult buffalo cows supply animal power (Robertson et al. 1994). When combined with the male workforce, 76% of all adult cattle (11.2 million) and 85 to 90% of all adult buffalo (0.41 million) are used for draught purposes (Khan 1983).

There is no aggregate shortage of draught animals. Rather, the shortfall is based on the quality of draught power available, since malnourished animals are largely unproductive (Orlic and Leng 1992).

There are various breeds of cattle used for draught purposes, including pure deshi cattle and deshi cattle crossed with Sahiwal, Haryana and Red Sindhi cattle and Manipuri, Nili-Ravi and Murrah breeds of buffalo. Deshi bullocks weigh an average of 225 kg, crossbreds are slightly heavier at 275 kg and buffalo weigh an average of 400 kg. Bulls, cows, heifers and bullocks all provide animal power, but bullocks constitute the main workforce.

In Bangladesh, land preparation employs the highest percentage of draught animals. Research workers recommend that land be ploughed six to seven times prior to sowing. However, due to the shortage of draught power, many producers plough only four to five times in preparation for each crop. All ploughs in Bangladesh require two animals. Two bullocks can plough 1 acre in 2.75 (at 6 hours each day) (Orlic and Leng 1992; Robertson et al. 1994).

Draught Power in China

China has a long history of buffalo raising. The animals were used for farming as early as 2,500 years ago. Buffalo have a larger body size than the native cattle. Farmers prefer to use buffalo for farm work because of their great draught power, long working life and docile temperament. One buffalo can provide draught power for the production of 7,500 to 12,500 kg of rice (Yang 1995). Most of them are kept by small-scale farmers for draught purpose. The imported dairy buffalo, Murrah and Nili/Ravi, and crossbreds with these two breeds, are mainly raised on state farms and in research institutes. For centuries, buffalo have been reared mainly for draught purposes. The animals were slaughtered for meat only when they become old or disabled. Milking of buffalo was rare. After generations of selection and breeding, the buffalo have become extremely suitable for working, with deep and strong chests, strong legs, large hoofs and a docile temperament.

In China, buffalo are mainly used for paddy land and for field haulage. They are also employed in raising water, pudding clay for bricks, milling and pressing the juice from sugarcane. The extent of such use is declining due to mechanization. Training of buffalo usually starts at the age of two years. They begin to work a year later. Their working life is longer than that of cattle, usually more than 17 years. It is possible to see buffalo more than 25 years old still working in the fields. They work 90 to 120 days per year in the rice-growing area, with intensive work in the spring and autumn, when they work as long as 7 to 8 hours per day. The working capability varies widely with size, age and sex of the animal. The draught power reaches its maximum between the age of five and 12 years, remains high from 13 to 15 and begins to decline from 16 years. Most of the buffalo bulls are castrated (Yang 1995).

The Shanghai buffalo, one of the largest in China, has an excellent working capability. Working for 8 hours a day, one animal can plough 0.27 to 0.4 hectare of paddy land or 0.4 to 0.53 hectare of non-irrigated land (maximum 0.67 hectare). A load of 800 to 1,000 kg on a wooden-wheeled, bearingless vehicle can be drawn by a buffalo over 24 km within a working day. A buffalo can raise enough water to irrigate 0.73 hectares of paddy land in 4 hours.

In some sugar-producing areas, buffalo are used to draw stone rollers for sugar cane pressing. Six buffalo working in shifts can press 7,500 to 9,000 kg of sugar cane, requiring 15 to 20 minutes for every 1,000 kg.

Draught Power in India

According to Ramaswami and Narasimhan (1982) 70 million bullocks and 8 million buffalo generate about 30,000 million watts of power, assuming the Indian Council of Agricultural Research (ICAR) average of 0.5 hp output per animal. To generate, transmit and distribute this power at the same multitudinous points of application would call for an investment of 3,000,000 million rupees. It has also been estimated that an investment of 30,000 million rupees has gone into the Indian bullock cart system as against 45,000 million rupees in railways.

The Ministry of Shipping and Transport estimated that 11,700 to 15,000 million tonnes of freight in the urban areas is carried by cart each year, as against the railway haulage of 200,000 million tonnes. In the rural areas, where railroad service is not available, animal-drawn vehicles carry approximately 3,000 million tonnes of freight (Gorhe 1983).

Draught Power in Nepal

In Nepal, bullocks and male buffalo are the main source of draught power for tilling the fields. They are also used for carting, crushing sugar cane and oil seeds and for tracting loads. Due to the topographic nature of the country as well as the high cost of fuel, there is little opportunity for farm mechanization. Therefore, the demand for draught animal power in the country is high (Joshi 1983).

In wheat production, the contribution of bullocks in terms of labour days is 42% in ploughing, 3% in transplanting and 55% in threshing. In paddy production, it is 63% in ploughing, 9% in transplanting and 28% in threshing (Joshi 1983; Stem, Joshi and Orlic 1995).

Depending on the task, draught animals are generally worked a consistent number of hours each day and for a predetermined number of consecutive days before being allowed to rest. For instance, a full day of ploughing averages 6 hours for a bullock, and the average workday for a cow ranges from 4 to 5 hours per day. Animals used for ploughing follow a pattern of 6 to 8 consecutive days of work, followed by 2 days of rest. In the case of threshing, cows or lighter-weight animals usually work for 6 to 8 hours each day. The length and pattern of use for threshing and transport varies according to need. A bullock in full-time ploughing (maximum heavy labour) typically works for 163 days per year.

Draught Power in Sri Lanka

The total cattle population in Sri Lanka is estimated at 1.3 million. Various breeds are used as draught animals. Cattle breeds are used for draught purposes such as transport and ploughing of both wet and dry fields, as well as in farm operations. Indigenous animals have been used popularly in road transport for several decades. Crosses of Indian breeds with the indigenous cattle have resulted in larger animals that are used extensively for road transport. Out of a total buffalo population of 562,000, the number available in the work age range of three to 12 years is estimated at 200,000 males and 92,000 females.

Potential Hazards and Their Control

Other articles in this chapter address hazards and preventive actions for the draught animals discussed in this article. General information on animal behaviour and a checklist for livestock rearing safety practices are found in articles on these subjects and in the article “Animal husbandry”. Horses are addressed in the article “Horses and other equines”. Cattle (and by close association, bullocks and buffalo) are addressed in the article “Cattle, sheep and goats”. “Bull raising” also offers pertinent information on potential hazards and their control.

 

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Monday, 28 March 2011 19:39

Case Study: Elephants

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The largest draught animal is the elephant, but its role is slowly becoming one of tradition rather than necessity. Two decades ago, 4,000 Asian elephants were used for logging in Thailand, but the forests there have been clear-cut and mechanization has displaced the elephant. However, they are still used in Myanmar, where elephant logging is prevalent. Logging companies frequently lease working elephants from their owners, who are typically urban businessmen.

The elephant handler (or trainer) is called an oozie in Myanmar and a mahout in India and Sri Lanka. The trainer mounts a saddle—a thick pad of leaves and bark—on the elephant’s back to protect its sensitive spine from the dragging gear, or tack, used in pulling logs. The trainer sits on the elephant’s neck as it uses its trunk, tusks, feet, mouth and forehead to accomplish its daily chores. A well-trained elephant in logging work will respond to more than 30 vocal commands and 90 pressure points on its body from a skilled handler. They work until 2:45 every afternoon, then the oozie scrubs the elephant in water with coconut halves for up to an hour. The oozie then feeds the elephant salted, cooked rice and hobbles and releases it to feed in the forest at night. At about 4:00 a.m., the oozie locates the elephant by unique tones of a bell that is attached to the elephant (Schmidt 1997).

Elephant bulls are rarely held in captivity, and cows are traditionally released to be bred in the wild. Artificial insemination is also used to breed elephants. Bull elephants donate semen to an elephant-sized artificial cow. It is impossible to observe visually the cow in oestrus (three times per year), so weekly samples of blood are taken for progesterone analysis. When a cow is in oestrus, she is bred by injecting semen into her vagina with a long, flexible pneumatic insemination tube.

Several hazards are associated with elephant handling; they arise from elephants’ size, the massive objects of their work and their behaviour. Mounting the tack on the elephant and manipulating logging gear exposes the handler to injury hazards. In addition, the handler is exposed to falls from the elephant’s neck. The potential for injury is aggravated by the logging operations, which include carrying, pushing, pulling and stacking; teak logs can weigh as much as 1,360 kg. The elephant’s behaviour may be unpredictable and cause injury to its handler. Captive bulls are very dangerous and are difficult to contain. Breeding bulls are particularly dangerous. A working bull elephant in Sri Lanka has been reported to have killed nine mahouts. He was retained after each death, however, because of his value to his owners (Schmidt 1997).

Some elephants will respond only to their trainer. The principal method for controlling unpredictable elephants is to allow only their oozie to handle them. Elephants are creatures of habit, so trainers should maintain a daily routine. The afternoon scrubbing by the trainer has been found to be critical in establishing a bond with the elephant. Maintaining the trainer’s dominance is another safeguard against unsafe elephant behaviour.

The swimmers who carry blood samples to a laboratory for progesterone analysis are exposed to a particularly dangerous task: they swim across rivers during the monsoon season. This drowning hazard can be corrected by providing laboratory services near the working elephants.

 

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Monday, 28 March 2011 19:36

Horses and Other Equines

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Horses belong to the equine family, which includes the domesticated African wild ass, also known as the donkey or burro. Historians believe that domestication of the horse began circa 6000 BC and the donkey at least as early as 2600 BC. The mule, bred for work, is a cross between a male donkey (jack or jackass) and a female horse (mare). A mule is unable to reproduce. When a male horse (stallion) is bred with a female donkey (jennet), the offspring, also sterile, is called a hinny. Horses and donkeys have also been crossed with another equine, the zebra, and the offspring are collectively called zebroids. Zebroids are also sterile and of little economic importance (Caras 1996).

Processes

Of the 10 million horses in the United States, about 75% are used for personal pleasure riding. Other uses include racing, ranching, breeding and commercial riding. The horse has become a performer in racing, jumping, rodeo and many more events.

The three main horse enterprises are breeding, training and boarding stables. Horse breeding farms breed mares and sell the offspring. Some farms specialize in training horses for show or racing. Boarding stables feed and care for horses for customers who have no facilities to house their horses. All three of these enterprises are labour intensive.

Horse breeding is an increasingly scientific process. Pasture breeding was typical, but now it is generally controlled within a breeding barn or corral. Although artificial insemination is used, it is more common that mares are brought to the stallion for breeding. The mare is checked by a veterinarian and, during breeding, trained workers handle the stallion and the mare.

After giving birth, the mare nurses the foal until it is from 4 to 7 months of age; after weaning, the foal is separated from the mare. Some colts not meant for breeding may be castrated (gelded) as early as 10 months of age.

When a racehorse becomes a two-year-old, professional trainers and riders start breaking it to ride. This involves a gradual process of getting the horse used to human touch, being saddled and bridled, and finally mounted. Horses that race with carts and heavy draught horses are broke to drive at about two years of age, and ranch horses are broke at closer to three years old, sometimes using the rougher method of bucking a horse out.

In horse racing, the groom leads the horse to the saddling paddock, a trainer and a valet saddle it, and a jockey mounts it. The horse is led by a pony horse and rider, warmed up and loaded into the starting gate. Racehorses can become excited, and the noise of a race can further excite and frighten the horse. The groom takes a winning horse to a drug test barn for blood and urine samples. The groom must then cool the horse down with a bath, walking and sipping water.

A groom cares for the performance horse and is responsible for brushing and bathing it, saddling it for the exercise rider, applying any protective bandages or boots to its legs, cleaning the stall and bedding down straw, shavings, peat moss, peanut skins, shredded newspaper or even rice hulls. The groom or a “hot” walker walks the horse; sometimes a mechanical walker is used. The groom feeds the horse hay, grain and water, rakes and sweeps, washes the horse’s laundry and carts manure away in a wheelbarrow. The groom holds the horse for others such as the veterinarian or farrier (farrier work is traditionally done by a blacksmith). All horses require parasite control, hoof care and teeth-filing.

Performance horses are typically stabled and given daily exercise. However, young stock and pleasure riding horses are generally stabled at night and released during the day, while others are kept outdoors in paddocks or pastures with sheds for shelter. Race horses in training are fed three or four times a day, while show horses, other performance horses, and breeding stock are fed twice a day. Range or ranch stock are fed once a day, depending on the forage present.

Horses travel for many reasons: shows, races, for breeding or to riding trails. Most are shipped by truck or trailer; however, some travel by rail or plane to major events.

Hazards and Precautions

Several hazards are associated with working around horses. A groom has a physically demanding job with a lot of forking of manure, moving 25 to 50 kg hay and straw bales and handling active horses. Startled or threatened horses may kick; thus, workers should avoid walking behind a horse. A frightened horse may jump and step on a worker’s foot; this can also occur accidentally. Various restraints are available to handle fractious horses, such as a chain over the nose or a lip chain. Stress on horses due to shipping may cause balking and injuries to the horses and handlers.

The groom is potentially exposed to hay and grain dust, dust from bedding, moulds, horse dander and ammonia from the urine. Wearing a respirator can provide protection. Grooms do a lot of leg work on the horses, sometimes using liniments containing hazardous chemicals. Gloves are recommended. Some leather-tack care products can contain hazardous solvents, requiring ventilation and skin protection. Cuts can lead to serious infections such as tetanus or septicaemia. Tetanus shots should be maintained current, especially because of exposure to manure.

A farrier is exposed to injury when shoeing a horse. The groom’s job is to hold the horse to keep it from kicking the farrier or pulling its foot in a way that could strain the farrier’s back or cut the farrier with the horseshoe and nails.

In the drug test barn, the test person is enclosed in a stall with a loose, excited and unfamiliar horse. He or she holds a stick (with a cup for urine) that may frighten the horse.

When riding horses, it is important to wear a good pair of boots and a helmet. Any mounted person needs a protective vest for racing, jumping, rodeo broncs, and ponying or exercising racehorses. There is always a danger of being bucked off or of a horse stumbling and falling.

Studs can be unpredictable, very strong and can bite or kick viciously. Brood mares are very defensive of their foals and can fight if threatened. Studs are kept individually in high-fenced paddocks, while other breeding stock are kept in groups with their own pecking order. Horses trying to move away from a boss horse or a group of yearlings at play can run over anyone who gets in the way. Foals, weanlings, yearlings and two-year-olds will bite and nip.

Some drugs (e.g., hormones) used in breeding are given orally and can be harmful to humans. Wearing gloves is recommended. Needle-stick injuries are another hazard. Good restraints, including stocks, can be used to control the animal during administration of medication. Topical sprays and automatic stable spray systems to control flies can easily be overused in horse rearing. These insecticides should be used in moderation, and warning labels should be read and recommendations followed.

There are a variety of zoonoses that can be passed from horses to humans, especially skin infections from contact with infected secretions. Horse bites can be a cause of some bacterial infections. See table 1 for a list of zoonoses associated with horses.

 


Table 1. Zoonoses associated with horses

 

Viral diseases

Rabies (very low occurrence)
Eastern, western and some subtypes of Venezuelan equine encephalomyelitis
Vesicular stomatitis
Equine influenza
Equine morbillvirus disease (first documented in Australia in 1994)

Fungus infections

Ringworm (dermatomycoses)

Parasitic zoonoses

Trichinosis (large outbreaks in France and Italy in the 1970s and 1980s)
Hydatid disease (echinoccosis) (very rare)

Bacterial diseases

Salmonellosis
Glanders (now very rare, restricted to Middle East and Asia)
Brucellosis (rare)
Anthrax
Leptospirosis (relatively rare, direct human contamination not definitively proven)
Melioidosis (outbreaks in France in the 1970s and 1980s; direct transmission not reported)
Tuberculosis (very rare)
Pasteurellosis
Actinobacillus lignieresii, A., A. suis (suspected in Lyme disease transmission, Belgium)


 

 

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The potential for back injuries and respiratory disorders is high for poultry catchers. Many poultry companies in the United States contract out catching birds. Due to the transient nature of the catching crews there are no data indicating injuries or losses. Usually, catching crews are picked up and driven to the grower by company-owned truck. The crew members are either given or sold single use disposable respirators and disposable cotton gloves to protect their hands. Companies should make sure that respiratory protection is worn properly and that their crews have been properly medically evaluated and trained.

Each catch crew member must reach down and grab several struggling birds one after another and may be required to handle multiple birds at once. The birds are placed in a tray or drawer of a multi-bay module. The module holds several trays and is loaded by a company-owned fork-lift onto the bed of the company’s flat bed trailer. The fork-lift operator may either be the company’s truck driver or the contract crew leader. In either case, proper training and operation of the fork-lift must be assured. Speed and coordination are essential among the catching crew.

New methods of catching and loading have been experimented with in the US. One method being tried is a guided gatherer which has arms sweeping inwards guiding the chickens to a vacuum system. Attempts at automation to reduce the physical stresses and potential for respiratory exposure are a long way from success. Only the larger, more efficient poultry companies can afford the capital expenditures necessary to purchase and support such equipment.

A chicken’s normal body temperature is 42.2 °C. Consequently, the mortality rate increases in the winter and in locations where the summers are hot and humid. Both in the summer and winter, the flock must be transported as quickly as possible to be processed. In the summer, prior to processing, trailer loads of modules containing birds must be kept out of the sun and cooled with large fans. Dust, dried faecal matter and chicken feathers are often airborne as a result.

Throughout the entire processing of chicken, rigid sanitation requirements must be met. This means floors must be periodically and often washed down and debris, parts and fat removed. Conveyors and processing equipment must be accessible, washed down and sanitized also. Condensation must not be allowed to accumulate on ceilings and equipment over exposed chicken. It must be wiped down with long-handled sponge mops.

In the majority of the processing plant’s production areas, there is high noise exposure. Unguarded overhead radial blade fans circulate the air in the processing areas. Because of the sanitation requirements, guarded rotating equipment cannot be silenced for noise abatement purposes. An appropriate and well-run hearing conservation programme is necessary. Initial audiograms and annual audiograms should be given and periodic dosimetry should be performed to document exposure. Purchased processing equipment need to have as low an operating noise level as possible.

Particular care needs to be taken in educating and training the workforce. Workers must understand the full implications of exposure to noise and how to wear their hearing protection correctly.

 

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Monday, 28 March 2011 19:30

Poultry and Egg Production

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Farm production of birds weighing 18 kg or less includes not only domestic birds such as chickens, turkeys, ducks, geese and guineas, but also game birds produced for hunting, such as partridges, quail, grouse and pheasants. While some of these birds are raised outdoors, the majority of commercial poultry and egg production occurs in specially designed confinement houses or barns. Larger birds weighing between 40 and 140 kg, such as cassowaries, rheas, emus and ostriches, are also raised on farms for their meat, eggs, leather, feathers and fat. However, because of their larger size, most of these birds, which are known collectively as ratites, are usually raised outdoors in fenced-in areas containing shelters.

Chickens and turkeys comprise the majority of poultry produced in the world. US farmers annually produce one-third of the world’s chickens—more than the next six leading chicken-producing countries combined (Brazil, China, Japan, France, the United Kingdom and Spain). Similarly, more than half the world’s turkey production occurs in the United States, followed by France, Italy, the United Kingdom and Germany.

While commercial chicken production occurred in the United States as early as 1880, poultry and egg production was not recognized as a large-scale industry until about 1950. In 1900, a chicken weighed slightly less than a kilogram after 16 weeks. Before the emergence of poultry production as an industry, chickens purchased for eating were seasonal, being most abundant in early summer. Improvements in breeding, feed-to-weight conversion, processing and marketing practices, housing and disease control contributed to the poultry industry’s growth. The availability of artificial vitamin D also made a major contribution. All these improvements resulted in year-round poultry production, shorter production periods per flock and an increase in the number of birds housed together from only a few hundred to several thousand. The production of broilers (7-week-old chickens weighing approximately 2 kg) increased dramatically in the United States, from 143 million chickens in 1940, to 631 million in 1950, to 1.8 billion in 1960 (Nesheim, Austic and Card 1979). US farmers produced approximately 7.6 billion broilers in 1996 (USDA 1997).

Egg production has also seen dramatic growth similar to broiler production. At the beginning of the twentieth century, a laying hen annually produced about 30 eggs, mostly in the spring. Today, the annual average per layer is more than 250 eggs.

Ratite farming primarily consists of the ostrich from Africa, the emu and cassowary from Australia and the rhea from South America. (Figure 1 shows a farm flock of ostriches, and figure 2 shows a farm flock of emus.) Ratite farming first started in South Africa in the late 1800s in response to a fashion demand for the wing and tail feathers of ostriches. While ostrich plumes no longer decorate hats and clothing, commercial production still occurs not only in South Africa, but also in other African countries such as Namibia, Zimbabwe and Kenya. Ratite farming also occurs in Australia, Germany, Great Britain, Italy, China and the United States. The meat of these birds is gaining popularity because, while it is a red meat with a beefy taste and texture, it has total and saturated fat levels much lower than beef.

Figure 1. Part of a commercial flock of 3- to 6-week old ostriches

LIV090F1

Roger Holbrook, Postime Ostrich, Guilford, Indiana

When processed at about 12 months of age, each bird will weigh approximately 100 kg, of which 35 kg is boneless meat. An adult ostrich can weigh as much as 140 kg.

Figure 2. Commercial flock of 12-month old emus

LIV090F2

Volz Emu Farm, Batesville, Indiana

When processed at about 14 months of age, each bird will weigh between 50 and 65 kilograms, of which approximately 15 kilograms is meat and 15 kilograms is fat for oil and lotions.

Poultry Confinement Housing

A typical poultry confinement house in the United States is a long (60 to 150 m), narrow (9 to 15 m) single-storey barn with a dirt floor covered with litter (a layer of wood shavings, sphagnum peat or sawdust). Both ends of a confinement house have large doors, and both sides have half-side curtains running the length of the structure. Watering systems (called drinkers) and automatic feeding systems are located close to the floor and run the entire length of a house. Large, 1.2-m diameter propeller fans are also present in a poultry house to keep the birds comfortable. A poultry farmer’s daily tasks include maintaining acceptable environmental conditions for the birds, ensuring the continuous flow of feed and water and collecting and disposing of dead birds.

Watering and feeding systems are raised 2.5 to 3 metres above the floor when a flock reaches its processing age to accommodate catchers, workers who collect the birds for transport to a poultry processing plant. Collecting chickens is usually done by hand. Each member of a crew must bend over or stoop to gather several birds at a time and place them into coops, cages or crates. Each worker will repeat this process several hundred times during a work shift (see figure 3). For other types of poultry (e.g., ducks and turkeys), workers herd the birds to a collection area. Turkey catchers wave sticks with red bags tied to them in order to separate several birds at a time from a flock and drive them into a holding pen at the barn’s entrance (see figure 4).

Figure 3. Chicken catchers collecting broilers and placing them in crates for delivery to a poultry processing plant.

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Steven W. Lenhart

Figure 4. Turkey catchers separating birds from a flock and driving them into a holding pen.

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Steven W. Lenhart

Poultry confinement houses vary from this general description depending primarily on the type of birds being housed. For example, in commercial egg production, adult hens or layers have traditionally been kept in cages arranged in parallel banks. Caged laying-hen systems will be banned in Sweden in 1999 and replaced by loose laying-hen systems. (A loose laying system is shown in figure 5). Another difference between poultry confinement houses is that some do not have litter-covered floors but instead have either slotted or plastic-coated wire floors with manure pits or liquid manure catchment areas under them. In western Europe, poultry confinement houses tend to be smaller than US houses, and they utilize block construction with cement floors for easy litter removal. Western European poultry confinement houses are also decontaminated and floor litter removed after every flock.

Figure 5. A loose laying system

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Steven W. Lenhart

Health Risks

The health and safety risks of poultry farmers, their family members (including children) and others who work in poultry confinement houses have increased as the poultry industry has grown. Raising a poultry flock requires a farmer to work 7 days a week. Consequently, unlike most occupations, exposures to contaminants occur over several consecutive days, with the period between flocks (as short as 2 days) being the only time of non-exposure to poultry house contaminants. The air of a poultry house can contain gaseous agents such as ammonia from litter, carbon monoxide from poorly ventilated gas-fired heaters and hydrogen sulphide from liquid manure. Also, particles of organic or agricultural dust are aerosolized from poultry house litter. Poultry house litter contains an assortment of contaminants including bird excreta, feathers and dander; feed dust; insects (beetles and flies), mites and their parts; micro-organisms (viral, bacterial and fungal); bacterial endotoxin; and histamine. The air of a poultry house can be very dusty, and for a first-time or occasional visitor, the smell of manure and the pungent odour of ammonia can at times be overwhelming. However, poultry farmers seemingly develop an adaptive tolerance to the smell and to ammonia’s odour.

Because of their inhalation exposures, unprotected poultry workers are at risk of developing respiratory diseases such as allergic rhinitis, bronchitis, asthma, hypersensitivity pneumonitis or allergic alveolitis and organic dust toxic syndrome. Acute and chronic respiratory symptoms experienced by poultry workers include cough, wheezing, excessive mucus secretion, shortness of breath and chest pain and tightness. Pulmonary function testing of poultry workers has provided evidence suggesting not only the risk for chronic obstructive diseases such as chronic bronchitis and asthma, but also restrictive diseases such as chronic hypersensitivity pneumonitis. Common non-respiratory symptoms among poultry workers include eye irritation, nausea, headache and fever. Of approximately 40 zoonotic diseases of agricultural importance, six (Mycobacterium avium infection, erysipeloid, listeriosis, conjunctival Newcastle infection, psittacosis and dermatophytosis) are of concern to poultry workers, although they occur only rarely. Non-zoonotic infectious diseases of concern include candidiasis, staphylococcosis, salmonellosis, aspergillosis, histoplasmosis and cryptococcosis.

There are also health issues affecting poultry workers that are as yet unstudied or poorly understood. For example, poultry farmers and especially chicken catchers develop a skin condition they refer to as galding. This condition has an appearance of a rash or dermatitis and primarily affects a person’s hands, forearms and inner thighs. The ergonomics of poultry catching are also unstudied. Bending to collect several thousand birds every work shift and carrying eight to fifteen chickens, each weighing from 1.8 to 2.3 kg, is physically demanding, but how this work affects a catcher’s back and upper extremities is unknown.

The extent to which the many psychosocial factors associated with farming have affected the lives of poultry farmers and their families is also unknown, but occupational stress is perceived by many poultry farmers as a problem. Another important but unstudied issue is the extent to which the health of farmers’ children is affected as a consequence of work in poultry houses.

Respiratory Health Protection Measures

The best way to protect any worker from exposure to airborne contaminants is with effective engineering controls that capture potential contaminants at their source before they can become airborne. In most industrial environments, airborne contaminants can be reduced to safe levels at their source by the installation of effective engineering control measures. Wearing respirators is the least desirable method for reducing workers’ exposures to airborne contaminants, and respirator use is recommended only when engineering controls are not feasible, or while they are being installed or repaired. Nevertheless, at present, wearing a respirator is still probably the most feasible method available for reducing poultry workers’ exposures to airborne contaminants. The general ventilation systems in poultry houses are not primarily intended to reduce the exposures of poultry workers. Research is going on to develop appropriate ventilation systems to reduce airborne contamination.

Not all respirators provide the same level of protection, and the type of respirator selected for use in a poultry confinement house can vary depending on the age of the birds being raised, age and condition of the litter, drinker type and position of the side curtains (open or closed). All of these are factors affecting airborne agricultural dust and ammonia concentrations. Airborne dust levels are highest during poultry-catching operations, at times to the point that one cannot see from one end of a poultry house to the other. A full-facepiece respirator with high-efficiency filters is recommended as the minimum protection for poultry workers based on bacterial endotoxin measurements made during chicken catching.

When ammonia levels are high, combination or “piggyback” cartridges are available that filter ammonia and particulates. A more expensive powered air-purifying respirator with a full-facepiece and high-efficiency filters may also be appropriate. These devices have the advantage that filtered air is constantly delivered to the wearer’s facepiece, resulting in less breathing resistance. Hooded, powered air-purifying respirators are also available and can be used by bearded workers. Respirators providing less protection than full-facepiece or powered air-purifying types may be adequate for some work situations. However, downgrading the level of protection, such as to a half-mask disposable respirator, is recommended only after environmental measurements and medical monitoring show that the use of a less protective respirator will reduce exposures to safe levels. Repeated exposures of the eyes to poultry dust increase the risk for eye injury and disease. Respirators with full-facepieces and those with hoods have a benefit of also providing eye protection. Poultry workers who choose to wear half-mask respirators should also wear eyecup goggles.

For any respirator to protect its wearer, it must be used in accordance with a complete respiratory-protection programme. However, while poultry farmers experience inhalation exposures for which respirator usage may be beneficial, most of them are not currently prepared to carry out a respiratory protection programme by themselves. This need may be addressed by the development of regional or local respiratory protection programmes in which poultry farmers can participate.

Manure pits should be considered confined spaces. A pit’s atmosphere should be tested if entry is unavoidable, and a pit should be ventilated if it is oxygen-deficient or contains toxic levels of gases or vapours. Safe entry may also require wearing a respirator. In addition, a standby person may be needed to stay in constant visual or speech contact with workers inside a manure pit.

Safety Risks

Safety risks associated with poultry and egg production include unguarded chains, sprockets, winches, belts and pulleys on fans, feeding equipment and other machinery. Scratches, pecks and even bites by the larger birds are also safety hazards. A male ostrich is especially protective of his nest during mating season, and when he feels threatened, he will attempt to kick any intruder. Long toes with sharp nails add to the danger of an ostrich’s powerful kick.

Electrical hazards created by improperly grounded or non-corrosion-resistant equipment or poorly insulated wires in a poultry house can result in electrocution, non-fatal electrical shock or fire. Poultry dust will burn, and poultry farmers tell anecdotes about accumulated dust exploding within gas-fired heaters when the dust was aerosolized during housekeeping chores. Researchers with the US Bureau of Mines have performed explosiveness testing of agricultural dusts. When aerosolized in a 20-litre test chamber and ignited, dust that was collected from the tops of heater cabinets and from window ledges in chicken houses was determined to have a minimum explosible concentration of 170 g/m3. Sieved samples of poultry house litter could not be ignited. By comparison, grain dust evaluated under the same laboratory conditions had a minimum explosible concentration of 100 g/m3.

Safety Measures

Measures can be taken to reduce safety risks associated with poultry and egg production. For protection from moving parts, all machinery should be guarded, and fans should be screened. For tasks involving hand contact with birds, gloves should be worn. High standards of personal hygiene should be maintained, and any injuries, no matter how minor, caused by machinery or birds should be treated immediately to avoid infection. When approaching a ratite, movement toward the bird should be from the side or behind to avoid being kicked. A lockout system should be used when servicing electrical equipment. Poultry farmers should frequently remove settled dust from surfaces, but they should be aware that, on rare occasions, an explosion can result when high concentrations of accumulated dust are aerosolized within an enclosure and ignited.

 

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Monday, 28 March 2011 19:29

Pigs

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Pigs were primarily domesticated from two wild stocks—the European wild boar and the East Indian pig. The Chinese domesticated the pig as early as 4900 BC, and today more than 400 million pigs are reared in China out of 840 million worldwide (Caras 1996).

Pigs are reared primarily for food and have many distinguishing attributes. They grow fast and large, and the sows have large litters and short gestation periods of about 100 to 110 days. Pigs are omnivores and eat berries, carrion, insects and garbage, as well as the corn, silage and pasture of high-production enterprises. They convert 35% of their feed into meat and lard, which is more efficient than ruminant species such as cattle (Gillespie 1997).

Production Processes

Some pig holdings are small—for example, one or two animals, which can represent much of a family’s wealth (Scherf 1995). Large pig operations include two major processes (Gillespie 1997).

One process is pure-bred production, in which pig breeding stock are improved. Within the pure-bred operation, artificial insemination is prevalent. Pure-bred boars are typically used to breed sows in the other major process, commercial production. The commercial production process rears pigs for the slaughter market and typically follows one of two different types of operations. One operation is a two-stage system. The first stage is feeder pig production, which uses a herd of sows to farrow litters of 14 to 16 piglets per sow. The pigs are weaned, then sold to the next stage of the system, the buying and finishing enterprise, which feeds them for the slaughter market. The most common feeds are corn and soybean oil meal. The feed grains are typically ground.

The other and most common operation is the complete sow and litter system. This production operation rears a herd of breeding sows and farrowing pigs, caring for and feeding the farrowed pigs for the slaughter market.

Some sows give birth to a litter that may outnumber her teats. To feed the excess piglets, a practice is to spread piglets from large litters into other sows’ smaller litters. Pigs are born with needle teeth, which are typically clipped at the gum-line before the pig is two days old. Ears are notched for identification. Tail docking occurs when the pig is about 3 days old. Male pigs raised for the slaughter market are castrated before they are 3 weeks old.

Maintaining a healthy herd is the single most important management practice in pig production. Sanitation and the selection of healthy breeding stock are important. Vaccination, sulpha drugs and antibiotics are used to prevent many infectious diseases. Insecticides are used to control lice and mites. The large roundworm and other parasites of pigs are controlled through sanitation and drugs.

Facilities used for pig production include pasture systems, a combination of pasture and low-investment housing and high-investment total-confinement systems. The trend is toward more confinement housing because it produces faster growth than does pasture rearing. However, pasture is valuable in feeding the pig-breeding herd to prevent fattening the breeding herd; it may be used for all or part of the production operation with the use of portable housing and equipment.

Confinement buildings require ventilation to control temperature and moisture. Heat may be added in farrowing houses. Slotted floors are used in confinement houses as a labour-saving approach for handling manure. Fencing and handling feeding and watering equipment are needed for the pig production enterprise. Facilities are cleaned by power washing and disinfecting after all bedding, manure and feed are removed (Gillespie 1997).

Hazards

Injuries from pigs usually occur within or close to farm buildings. Dangerous environments include slippery floors, manure pits, automatic feeding equipment and confinement buildings. Confinement buildings have a manure storage pit that emits gases that, if not ventilated, can kill not only pigs, but workers as well.

Pig behaviour can pose hazards to workers. A sow will attack if her piglets are threatened. Pigs can bite, step on or knock people down. They tend to stay in or return to familiar areas. A pig will try to return to the herd when attempts are made to separate it. Pigs are likely to balk when moved from a dark area into a light area, such as out of a pig house into the daylight. At night, they will resist moving into dark areas (Gillespie 1997).

In a Canadian study of pig farmers, 71% reported chronic back problems. Risk factors include intervertebral disc loading associated with driving and sitting for long periods while operating heavy equipment. This study also identified lifting, bending, twisting, pushing and pulling as risk factors. In addition, more than 35% of these farmers reported chronic knee problems (Holness and Nethercott 1994).

Three types of air exposures pose hazards on pig farms:

  1. dust from feed, animal hair and faecal matter
  2. pesticides used on pigs and other chemicals, such as disinfectants
  3. ammonia, hydrogen sulphide, methane and carbon monoxide from manure storage pits.

 

Fires in buildings are another potential hazard, as is electricity.

Some zoonotic infections and parasites can be transmitted from the pig to the worker. Common zoonoses associated with pigs include brucellosis and leptospirosis (swineherd’s disease).

Preventive Action

Several safety recommendations have evolved for the safe handling of pigs (Gillespie 1997):

  • Working with small pigs in the same pen as the sow should be avoided.
  • A hurdle or solid panel should be used when handling pigs to avoid bites and being knocked over.
  • A pig can be moved backwards by placing a basket over its head.
  • Children should be kept out of pig pens and not allowed to reach through fences to pet pigs.
  • Because of their herding instincts, it is easier to separate a group of pigs from a herd than a single animal.
  • Pigs can be moved from dark to light areas with the use of artificial light. When pigs are moved at night, such as through chutes or alleys, a light should be placed at the destination.
  • Loading chutes should be level or at not more than a 25-degree angle.

 

Musculoskeletal injury risk can be decreased by reducing exposure to repetitive trauma (by taking frequent breaks or by varying the kinds of tasks), improving posture, reducing the weight lifted (use co-worker or mechanical assistance) and avoiding rapid, jerking movements.

Dust control techniques include lowering stock density to reduce dust concentration. In addition, automatic feed delivery systems should be enclosed to contain dust. Water misting can be used, but it is ineffective in freezing weather and can contribute to the survival of bioaerosols and increase endotoxin levels. Filters and scrubbers in the air handling system show promise in cleaning dust particles from recirculated air. Respirators are another way to control dust exposures (Feddes and Barber 1994).

Vent pipes should be installed in manure pits to prevent dangerous gases from recirculating into the farm buildings. Electrical power should be maintained to vent fans at the pits. Workers should be trained in the safe use of pesticides and other chemicals, such as disinfectants, used in pig production.

Cleanliness, vaccination, quarantine of sick animals and avoiding exposures are ways to control zoonoses. When treating sick pigs, wear rubber gloves. A person who becomes sick after working with sick pigs should contact a physician (Gillespie 1997).

 

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Contents

Preface
Part I. The Body
Part II. Health Care
Part III. Management & Policy
Part IV. Tools and Approaches
Part V. Psychosocial and Organizational Factors
Part VI. General Hazards
Part VII. The Environment
Part VIII. Accidents and Safety Management
Part IX. Chemicals
Part X. Industries Based on Biological Resources
Part XI. Industries Based on Natural Resources
Part XII. Chemical Industries
Part XIII. Manufacturing Industries
Part XIV. Textile and Apparel Industries
Part XV. Transport Industries
Part XVI. Construction
Part XVII. Services and Trade
Part XVIII. Guides