Beef cattle breeds

The British Isles led the world in the development of the principal beef breeds; Herefords, Angus, beef Shorthorns, and Galloways all originated in either England or Scotland. Other breeds of greatest prominence today originated in India (Brahman), France (Charolais; Limousin; Normandy), Switzerland (Simmental), and Africa (Africander). The Hereford breed, considered to be the first to be developed in England, probably descended from white-faced, red-bodied cattle of Holland crossed with the smaller black Celtics that were native to England and especially to Herefordshire. By the middle of the 18th century the slow process of selective breeding that resulted in the smooth, meaty, and prolific Herefords had begun. The United States statesman Henry Clay of Kentucky imported the first purebred Herefords to America in 1817.

The Hereford, which became the most popular beef breed of the United States, is distinguished by its white face, white flanks and underline, white stockings and tail, and white crest on the neck. Its body colour ranges from cherry to mahogany red. It is of medium size, with present-day breeders making successful efforts to increase both its rate of weight gain and mature size, in keeping with the demand for cheaper, leaner beef.

The Polled Hereford is a separate breed of cattle originating from hornless mutations in 1901. It has the same general characteristics as the horned Hereford and has gained substantial favour because of its hornlessness and often faster rate of weight gain.

The Aberdeen Angus breed originated in Scotland from naturally hornless aboriginal cattle native to the counties of Aberdeen and Angus. Solid black, occasionally with a spot of white underneath the rear flanks, the breed is noted for its smoothness, freedom from waste, and high quality of meat.

Although the native home of the Galloway breed is the ancient region of Galloway in southwestern Scotland, it probably had a common origin with the Angus. The Galloway is distinguished by its coat of curly black hair. Though the breed has never attained the prominence of other beef breeds, it has been used extensively in producing blue-gray crossbred cattle, obtained by breeding white Shorthorn bulls to Galloway cows.

The beef, or Scotch, Shorthorn breed developed from early cattle of England and northern Europe, selected for heavy milk production and generally known as Durham cattle. These were later selected for the compact, beefy type by the Scottish breeders. Emphasis on leaner, highquality carcasses in the second half of the 20th century has diminished the popularity of this breed. The Polled Shorthorn originated in 1888 from purebred, hornless mutations of the Shorthorn breed. The milking, or dual-purpose, Shorthorn, representing another segment of the parent Shorthorn breed, also was developed in England to produce an excellent flow of milk as well as an acceptable carcass, therefore resembling the original English type of Shorthorn. Shorthorns range in colour from red through roan, to white- or red-and-white-spotted.

The Brahman breed originated in India, where 30 or more separate varieties exist. Preference is given to the Guzerat, Nellore, Gir, and Krishna Valley strains, which are characterized by a pronounced hump over the shoulders and neck; excessive skin on the dewlap and underline; large, droopy ears; and horns that tend to curve upward and rearward. Their colour ranges from near white through brown and brownish red to near black. Their popularity in other areas such as South America and Europe, into which they have been imported, is attributable mainly to their heat tolerance, drought resistance, and resistance to fever ticks and other insects. The Santa Gertrudis was developed by the King Ranch of Texas by crossing Brahman and Shorthorn cattle to obtain large, hearty, tick-resistant, red cattle that have proved to be popular not only in Texas but in many regions along the semitropical Gulf Coast. Until the tick was eradicated in the southern and southwestern United States, Brahman crosses were raised almost exclusively there.

Several lesser breeds have been developed from crosses of the Brahman on other beef breeds such as: the Charbray (Charolais), Braford (Hereford), Brangus (Angus), Brahorn (Shorthorn), and Beefmaster (Brahman-Shorthorn-Hereford).

The Charolais breed, which originated in the Charolais region of France, has become quite popular in the United States for crossing on the British breeds for production of market cattle. The superior size, rate of gain, and heavy muscling of the pure French Charolais and the hybrid vigour accruing from the crossing of nonrelated breeds promise an increased popularity of this breed. Many American Charolais, however, carry significant amounts of Brahman blood, with a corresponding reduction in size, rate of gain, and muscling. Important in France, the Charolais is the foremost meat-cattle breed in Europe.

The Limousin breed, which originated in west central France, is second in importance to the Charolais as a European meat breed. Limousin cattle, often longer, finer boned, and slightly smaller than the Charolais, are also heavily muscled and relatively free from excessive deposits of fat.

The most prevalent breed of France, the Normandy, is smaller than the Charolais or Limousin and has been developed as a dual-purpose breed useful for both milk and meat production. A fourth important breed is the Maine–Anjou, which is the largest of the French breeds.

The Simmental accounts for nearly half of the cattle of Switzerland, Austria, and the western areas of Germany. Smaller than the Charolais and Limousin, the Simmental was developed for milk, meat, and draft. It is yellowish brown or red with characteristic white markings.

Beef cattle feed

Beef cattle can utilize roughages of both low and high quality, including pasture forage, hay, silage, corn (maize) fodder, straw, and grain by-products. Cattle also utilize nonprotein nitrogen in the form of urea and biuret feed supplements, which can supply from one-third to one-half of all the protein needs of beef animals. Nonprotein nitrogen is relatively cheap and abundant and is usually fed in a grain ration or in liquid supplements with molasses and phosphoric acid or is mixed with silage at ensiling time; it also may be used in supplement blocks for range cattle or as part of range pellets. Other additions to diet include corn (maize), sorghum, milo, wheat, barley, or oats. Fattening cattle are usually fed from 2.2 to 3.0 percent of their live weight per day, depending on the amount of concentrates in the ration and the rate at which they are being fattened. Such cattle gain from 2.2 to 3.0 pounds (1.0 to 1.4 kilograms) per day and require from 1.3 to 3.0 pounds (0.6 to 1.4 kilograms) of crude protein, according to their weight and stage of fattening. Up until the early 1970s, when the practice was prohibited, fattening cattle were given the synthetic hormone diethylstilbestrol as a supplement in their feed or in ear implants. The use of this synthetic hormone results in a 10 to 20 percent increase in daily gain with less feed required per pound of gain. Synthetic vitamin A sources have become so cheap as to permit the use of 10,000 to 30,000 International Units per day for cattle being fattened for market (finished) in enclosures bare of vegetation (drylots) used for this purpose. The economics of modern cattle finishing encourages the use of all-concentrate rations or a minimum of roughage, or roughage substitutes including oyster shells, sand, and rough plastic pellets. Corn (maize) silage produces heavy yields per acre at a low cost and makes excellent roughage for beef-cattle finishing.

Beef cows kept for the production of feeder calves are usually maintained on pasture and roughages with required amounts of protein supplement and some grain being fed only to first-calf heifers or very heavy milking cows. Most beef cows tend to be overnourished and may become excessively fat and slow to conceive unless they happen to be exceptionally heavy milkers. Most pregnant cows go into the winter in satisfactory condition and need to gain only enough to offset the weight of the fetus and related membranes. They can therefore utilize coarser roughages, having a total daily crude protein requirement of from 1.3 to 1.7 pounds (0.58 to 0.76 kilograms). Daily vitamin A supplement at the rate of 18,000 to 22,000 International Units per cow is advisable unless the roughages are of a green, leafy kind and the fall pasture has been of excellent quality. Feed requirements for bulls vary with age, condition, and activity, from 2.0 to 2.4 pounds of crude protein per day; from 25,000 to 40,000 International Units of vitamin A; and during breeding periods nearly the same energy intake as calves or short yearlings being finished for market, the main feeding requirement being to prevent their becoming excessively fat.

All cattle require salt (sodium chloride) and a palatable source of both calcium and phosphorus, such as limestone and steamed bone meal. Most commercial salts carry trace minerals as relatively cheap insurance against deficiencies that occasionally exist in scattered locations.

Beef cattle management

Beef production has become highly scientific and efficient because of the high cost of labour, land, feed, and money. Most brood-cow herds, which require a minimum of housing and equipment, are managed so as to reduce costs through pasture improvement and are typically found in relatively large areas and herds. Other aspects of management include performance testing for regular production of offspring that will gain rapidly and produce acceptable carcasses and the use of preventive medicine, feed additives, pregnancy checks, fertility testing of sires, artificial insemination of some purebred and commercial herds, protection against insects and parasites, both internal and external, adequate but not excessive feed intakes, and a minimum of handling.

Calving of beef cows is arranged to occur in the spring months to take advantage of the large supplies of cheap and high-quality pasture forages. Fall calving is less common and occurs generally in regions where winters are moderate and supplies of pasture forage are available throughout the year. Calves are normally weaned at eight to ten months of age because beef cows produce very little milk past that stage and also because they need to be rested before dropping their next calf. Feeder calves sell by the pound, so that weight for age is even more important than conformation or shape. Consequently, crossbred cattle are used; their hybrid vigour results in greater breeding efficiency and milk production on the part of the dam, as well as greater birth weight, vigour, and gaining ability on the part of the offspring.

Beef cows are normally first bred at 15 to 18 months. The gestation period is 283 days, and the interval between estrus, or periods in which the dam is in heat, is 21 days. Cows should produce a living calf every 12 months. Pasture breeding, in which nature is allowed to take its course, calls for one mature bull for every 25 cows, whereas hand breeding, in which control is exercised by the breeder, requires half as many bulls. Artificial insemination permits one outstanding sire to produce thousands of calves annually.

Diseases of beef and dairy cattle

Dairy cattle are susceptible to the same diseases as beef cattle. Many diseases and pests plague the cattle industries of the world, the more serious ones being prevalent in the humid and less developed countries. One of the more common diseases to be found in the developed countries is brucellosis, which has been controlled quite successfully through vaccination and testing. This disease produces undulant fever in humans through milk from infected cows. Leptospirosis, prevalent in warm-blooded animals and humans, is caused by a spirochete and results in fever, loss of weight, and abortion. Bovine tuberculosis has been largely eliminated; where it has not, it can infect other warm-blooded animals, including humans. Test and slaughter programs have proved effective. Rabies, caused by a specific virus that also can infect most warm-blooded animals, is usually transmitted through the bite of infected animals, either wild or domestic. Foot-and-mouth disease has been eliminated from most of North America, some Central American countries, Australia, and New Zealand. The rest of the world is still plagued by the disease, which attacks all cloven-footed animals. Humans are mildly susceptible to this organism. Successful vaccinations have been developed for blackleg, malignant edema, infectious bovine rhinotracheitis (or red nose), and several other diseases. Anaplasmosis, common to most tropical and semitropical regions, is spread by the bite of mosquitoes and flies. Anthrax, caused by a generally fatal bacterial infection, has been largely eliminated in the United States and western Europe. Rinderpest, still common to Asia and Europe, is caused by a specific virus that produces high fever and diarrhea. An infectious fever sometimes called nagana, caused by the tsetse fly, attacks both cattle and horses and is prevalent in central and southern Africa, as well as in the Philippines. Grass tetany and milk fever both result from metabolic disturbances. Bloat, caused by rapid gas formation in the rumen, or first compartment of the stomach, is sometimes fatal unless relieved. Pinkeye is an infectious inflammation of the eyes spread by flies or dust and is most serious in cattle having white pigmentation around one or both eyes. Mastitis, an inflammation of the udder, is caused by rough handling or by infection. Vibriosis, a venereal disease that causes abortion; pneumonia, an inflammation of the lungs; and shipping fever all cause serious losses and are difficult to control except through good management. Broad-spectrum antibiotics (antibiotics that are effective against various microorganisms), as well as powerful and specific pharmaceuticals, are effective and profitable means of keeping cattle herds healthy. Vermifuges, which destroy or expel parasitic worms, and insecticides, which kill harmful insects, are also highly effective and much used.

Breeds

Pigs have a gestation period of 114 days with a 21-day interval between periods of estrus. A boar can mate with 15 to as many as 45 sows per year. The average litter consists of seven pigs, each with a birth weight of 2.5 pounds (1.1 kilograms). Sows should each produce 1.5 litters or more per year. Most market pigs are produced from crossbred sows by a boar of a third breed. There are more than 300 known breeds or local varieties of pigs throughout the world. A brief description follows of the better-known commercial breeds that have figured prominently in improving and upgrading domestic breeds and crosses throughout the world.

The Hampshire pig, which originated from the Norfolk thin-rind breed of England, is black with a white belt completely encircling its body and both front legs and feet. There should be no white on the head or the ham.

The Yorkshire pig, which originated early in the 19th century in England, where it was considered a bacon type, is long, lean, and trim with white hair and skin. Found in most countries, this breed is probably the most widely distributed in the world.

The Duroc-Jersey breed originated in the eastern United States from red pigs brought by Columbus and de Soto. The modern Duroc, originated from crosses of the Jersey Red of New Jersey and the Duroc of New York in the late 19th century, ranges from golden-red to mahogany-red in colour, with no black allowed. This breed proved particularly suitable for feeding in the U.S. Corn Belt (parts of Ohio, Indiana, Illinois, Wisconsin, Minnesota, South Dakota, Nebraska, Missouri, and Oklahoma; all of Iowa) and has been extensively used in Argentina, Canada, Chile, and Uruguay. The Poland China originated about 1860 in southern Ohio from a number of different breeds common to that area. The Spotted originated in Indiana about 1915 from crosses of the Poland China and the native spotted pigs. The Chester White, which originated in Chester County, Pennsylvania, after 1818, is restricted to the United States and Canada. The Berkshire, which originated in Berkshire, England, about 1770, is used for fresh pork production in England and Japan; a larger bacon type has been evolved in Australia and New Zealand. The Landrace is a white, lop-eared pig found in most countries in central and eastern Europe, with local varieties in Denmark, Germany, The Netherlands, and Sweden. World attention was first drawn to the Landrace by Denmark where, since 1890, by progeny testing (the selection of boars for breeding on the basis of the scientific assessment of their progeny), a superior pig, designed for Denmark's export trade in Wiltshire bacon to England, has been produced. Denmark no longer permits the export of Landrace for breeding. Sweden also has progeny tested from Landrace stock but for a shorter period. Pigs from Sweden were first exported to England in 1953, when prices of up to £1,000 were paid. This resulted in a worldwide Landrace explosion, and most major pig-producing countries have since taken stock.

The importance of the Asian pig breeds was recognized in the use of Chinese and “Siamese” pigs from southeastern Asia in the improvement of early European and North American breeds and is reflected in the name of the world-famous Poland China. China leads the world in pig numbers, and pork is traditional in the Chinese diet. Exports from China are substantial.

Feeding

Corn (maize) is a favourite feed for pigs, but wheat, sorghum, milo, barley, and oats also are used if the price is favourable. Wherever abundant and reasonable in price, soybean-oil meal is a favourite source of protein, and other oil meals and high-protein by-products are used in some countries. Antibiotics to control disease have become a standard ingredient in most pig rations. Improvements in breeding, disease control, management, and feed formulation have all contributed to faster gains and lower feed requirements per pound of weight gain. The use of antibiotics after World War II, especially in regions of less favourable sanitation, increased gain by as much as 20 percent.

Management

Diseases

Pigs are subject to many infectious and parasitic diseases. Among the more common of these is transmissible gastroenteritis, an infectious disease often fatal to young pigs. Cholera, formerly controlled by vaccination, is now controlled by slaughter of infected animals. Leptospirosis, common to pigs as well as humans and most warm-blooded animals, can be controlled by vaccination. Necrotic enteritis and other infections of the intestinal tract are largely controlled by antibiotics. Atrophic rhinitis produces sneezing, crooked snouts, and unthriftiness (little or no weight gain even with proper feeding). Erysipelas, a bacterial infection of pigs, turkeys, and humans, causes in pigs inflammation of the skin, a swelling and stiffness of joints, and unthriftiness; it can be controlled through a vaccination program. Parasitic diseases are controlled mainly through effective sanitation programs and are less of a problem under confinement raising than when pigs are raised in the open. Effective vermifuges, which kill or expel parasitic worms, have been developed for further control. Production in the United States, the Scandinavian countries, and western Europe has been developed to a high state of efficiency, largely through effective control of infectious and parasitic diseases.

Breeds

The gestation period for sheep is 147 days with 16.7 days between periods of estrus, which last 29 hours. The average number of lambs raised per hundred ewes is 91, and the average fleece weight per shearing is 8.34 pounds (3.78 kilograms).

Of more than 200 breeds of sheep in existence in the world, the majority are of limited interest except in the localities where they are raised. Sheep breeds are generally classified as medium wool, long wool, and fine wool. Of the medium wool breeds the Hampshire, Shropshire, Southdown, Suffolk, Oxford, and Dorset all originated in England. The Cheviot and Black Faced Highland originated in Scotland. The Panama, Columbia, and Targhee were developed in the United States, and the Corriedale in New Zealand. After World War II such larger breeds as the Suffolk and Hampshire increased in popularity at the expense of the smaller breeds.

The long wool breeds, including the Cotswold, Lincoln, Leicester, and Romney, were all developed in England and, in addition to mutton, produce wool of unusually long fibre length that is suitable for rugs and coarse fabrics.

The original fine-wool breed was the Merino, developed in Spain from stock native to that country before the Christian era. Though medieval Spain sought to preserve a monopoly on the Merino, the sheep gradually spread to France, Italy, and the rest of Europe. Today the Merino is prominent in Australia, the United States, Russia, South Africa, Argentina, France, and Germany; the breed is designated by various names such as Australian Merino in Australia and Merino Transhumante in Spain. The Merino was the main ancestor of the French Rambouillet, somewhat larger and less wrinkled than the Merino. This breed prospers in the western ranges of the United States, where two-thirds of that country's sheep are raised. The Corriedale breed, adapted to both farms and ranges, is especially valued in New Zealand and Australia. Most commercial sheep today represent two-breed or three-breed crosses, with white-faced crossbred ewes preferred in the range areas and a black-faced sire, such as Suffolk or Hampshire, preferred for market lambs, which are either finished for slaughter or sold as breeding ewes.

Feeding

Sheep are excellent foragers and, being ruminants, can utilize both pasture forage and harvested roughage. Selective in their grazing habits, they prefer short grass when available. Pregnant ewes can run on late pasture as long as it is available and abundant but in winter subsist satisfactorily on well-cured legume hay or mixed hay carrying a high percentage of legume. Corn (maize) silage is relatively inexpensive and relished by sheep; lactating ewes and lambs being finished for market usually require some concentrate, with corn (maize) favoured because of its high energy content and reasonable cost.

Range sheep grazing selectively on native plants frequently develop mild deficiencies of protein, energy, phosphorus, and vitamin A, especially when plants are mature or dormant or are eaten by ewes in the later stages of pregnancy or lactation. Broad spectrum antibiotics at the rate of five to 10 milligrams per pound of feed are normally used in all lamb finishing rations to prevent digestive disturbances and infections.

Management

Range sheep are normally white-faced crosses carrying both long-wool and Rambouillet breeding and are consequently very hardy and thrifty. They are wintered in bands, or flocks, of from 1,000 to 4,000 head at lower altitudes, and are moved in bands ranging from 1,000 to 1,500 head to summer range at much higher altitude, sometimes 300 miles (480 kilometres) from their winter quarters. Each flock is tended by a sheepherder and his dogs who move systematically from one grazing area to another. The herder often lives in a covered wagon or truck and may spend weeks at a time in complete solitude. The most famous sheepherders are the Basques, who emigrated widely from their home in Spain. The breeding ewes are mated to Suffolk or Hampshire rams and produce lambs during the late winter or early spring so that the lambs will be old enough to move to summer grazing without difficulty.

In many parts of the world small flocks are kept partly as scavengers to clean up fence rows, weeds, brush, and other undesirable forage, but this is a diminishing role. Large flocks are maintained partly for wool and partly for market lambs. Lambs are usually dropped in the spring and are sold at ages of from three to eight months and weights of around 40 pounds (18 kilograms) for Easter lambs, and 100 pounds (45 kilograms) for the usual market lambs. Sheep are sheared in the spring after the worst winter weather has passed. Some breeds are noted for producing a high percentage of twins, and others, such as the Dorset, for both high frequency of twins and heavy milk production. Shepherds frequently switch a newly born twin lamb to a ewe that has just lost a single lamb, thereby utilizing the extra milk. This practice requires skill and experience, since a mother ewe recognizes her own lamb by both its smell and the sound of its call.

Diseases

Such internal parasites as the tapeworm and several species of roundworms that infest the gastrointestinal tract are perhaps the greatest scourge of sheep, but modern vermifuges are quite effective against these. Dips are used to combat such external parasites as ticks, lice, and mites. Foot rot, caused by an infection of the soft tissue between the toes, results in extreme lameness and even loss of the hoof. The more persistent type is caused by a specific organism that is difficult to treat. The pain and the restricted movement of infected sheep result in rapid loss of weight. Enterotoxemia, or pulpy kidney, affects lambs at two to six weeks of age, especially those starting on unusually lush or rich feeds. A vaccination is quite effective in preventing this otherwise costly ailment.

Breeds

Table of Selected Breeds of Light Horses The Arabian, the oldest recognized breed of horse in the world, is thought to have originated in Arabia before AD 600. Though its history is lost in the past, the breed probably descended from the Libyan horse, which, in turn, was probably preceded by horses of similar characteristics in Assyria, Greece, and Egypt as early as 1000 BC. The Arabian may be bay, gray, chestnut, brown, black, or white in hair colour, but always has a black skin. It ranges from 14.1 to 15.1 hands (4.7 to 5.0 feet, or 1.4 to 1.5 metres) in height. The Arabian horse has one lumbar vertebra less than other breeds of horse and is characterized by the high carriage of its head, long neck, and spirited action.

The Thoroughbred racing horse is descended from three desert stallions brought to England between 1689 and 1724; all of the Thoroughbreds of the world today trace their ancestry to one of these stallions.

The American Saddle Horse, which originated in the United States, was formed by crossing Thoroughbreds, Morgans, and Standardbreds on native mares possessing an easy gait. The American Saddle Horse is 15 to 16 hands (5 to 5.3 feet, or 1.5 to 1.6 metres) in height. Its colours are bay, brown, black, gray, and chestnut. There are two distinct types of the American Saddle Horse: three-gaited and five-gaited. The three natural gaits are walk, trot, and canter. Three-gaited saddle horses are shown with a short tail and cropped mane. They often have slightly less style and finish than the five-gaited horse. The five-gaited saddle horse has the three natural gaits plus the rack and a slow gait, which is usually a stepping pace. The American Saddle Horse is also used as a fine harness horse mainly for show.

The American Quarter Horse traces to the Thoroughbred, and includes the blood of other breeds, such as the Morgan, the American Saddle Horse, and several strains of native horses. This fast, muscular horse has been raced, ridden in rodeos, and used for herding cattle.

The typical Quarter Horse is 15 to 16 hands tall and is of powerful build, suitable for both racing and the rough life of a cow pony. This horse is noted for its intelligence, easy disposition, and cow sense.

The Tennessee Walking Horse, or plantation horse, traces mainly to the Standardbred but also includes Thoroughbred and American Saddle Horse blood. The Tennessee Walking Horse is noted for its running walk, a slowgliding gait in which the hind foot oversteps the print of the front foot by as much as 24 inches (600 millimetres). This breed is 15.2 to 16 hands high and is bay, black, chestnut, roan, or gray in colour.

The Morgan traces directly to “the Justin Morgan horse,” foaled in 1793, of unknown breeding but no doubt tracing to Arabian stock. A dark bay in colour, Morgan stood 14 hands high and weighed 950 pounds (430 kilograms). He was a heavily muscled, short-legged horse of great style, quality, and endurance. He is the world's best example of prepotency, since he alone founded the Morgan breed. The Morgan is used for both riding and driving. It ranges from 14 to 16 hands in height and resembles the Arabian in size, conformation, quality, and endurance.

The American Standardbred originated around New York City during the first half of the 19th century from Thoroughbred, Morgan, Norfolk Trotter, Arabian, Barb, and pacers of mixed breeding. The modern Standardbred is smaller than the Thoroughbred, ranging from 15 to 16 hands in height and averaging about 15.2 hands. In racing condition it weighs from 900 to 1,000 pounds (410–450 kilograms). Stallions in stud condition average from 1,100 to 1,200 pounds (500–545 kilograms). Compared with the Thoroughbred, the Standardbred is longer-bodied, shorter-legged, heavier-boned, and stockier in build. Prevailing colours are bay, brown, and chestnut.

Draft horses have largely been supplanted by trucks and tractors in the developed countries of the world. Major draft breeds include the Percheron, developed in France; the Clydesdale of Scotland; the Shire of England; the Suffolk of England; and the Belgian of Belgium. These breeds range from 15¹/₂ to 17 hands in height at the withers; at maturity the mares weigh from 1,600 to 2,000 pounds (720–900 kilograms) and the stallions from 1,900 to 2,200 pounds (860–1000 kilograms).

The more popular pony breeds are the Shetland, which originated in the Shetland Islands, and the Hackney, of English origin. Ponies must be under 14.2 hands in height at the withers and are used both for show and for children's pleasure.

Feeding

The specific and exact nutrient requirements of horses are poorly understood. Usually, these may be supplied economically from pasture forage, harvested roughages, and concentrates. Good quality grass-legume pastures, in addition to iodized or trace-mineralized salt, will supply adequate nutrients to maintain an adult horse at light work (such as pulling a small cart) or mares during pregnancy. Lush, early spring pasture is very high in water and protein contents and may need to be supplemented with a high-energy source, such as grain, to meet the needs of horses performing medium to heavy work (such as plowing). Conversely, late fall- and winter-pasture forage is low in water and protein and may require protein and vitamin A supplementation. High-quality legume hays, such as early bloom alfalfa, are preferred for horses, especially those that are growing or lactating. Moldy or dusty feeds should be avoided because horses are extremely susceptible to forage poisoning and respiratory complications. Grass hays, such as timothy, prairie grass, orchard grass, and bluegrass, were preferred by early horsemen, especially for race horses, because they were usually free from mold and dust and tended to slow down the rate of passage through the intestinal tract. These hays are low in digestible energy and protein, however, and must be adequately supplemented. Silages of all sorts should be avoided since horses and mules are extremely susceptible to botulism and digestive upsets.

Oats are the preferred grain for horses because of their bulk. Corn (maize), barley, wheat, and milo can be used, however, whenever they are less expensive. Weanling foals require three pounds of feed per hundred pounds of live weight per day; as they approach maturity, this requirement drops to one pound of feed per hundred pounds of live weight daily. Horses normally reach mature weight at less than four years of age and 80 percent of their mature weight at less than two years of age.

A large and ever-growing number of horses stabled in cities and suburbs where sufficient roughages cannot be grown provide a large market for complete horse rations, including roughage, which are tailored to the total needs of specific animals according to their particular function at a given time, such as growth, pregnancy, lactation, or maintenance.

Horses will vary from the normal requirement in terms of weight, temperament, and previous nutrition. Foals will eat some pasture grass, forage, or hay when they are three days old and grain when they are three weeks old.

Management

Highly bred light horses are notoriously poor reproducers. Many horse farms consider a 60 percent foaling rate for a large band of mares to be average. Most large horse farms employ resident veterinarians to check for abnormalities or disease before breeding and to check mares for pregnancy 40 to 45 days after breeding. Because many mares conceive only every other year, expert assistance at foaling time is an absolute necessity, especially if the foal is sired by an expensive stallion out of a valuable mare.

The gestation period of horses is 340 days. The period between estrus ranges from 18 to 28 days with an average of 22 days. Mature stallions can safely mate with from 50 to 100 mares per season, although the practice with expensive Thoroughbreds is to book no more than 35 to 40 mares.

The feet and legs of horses demand unusual attention. The old adage “no foot no horse” remains apt. Hooves should be trimmed regularly, beginning when the horse is a foal or only a few months old. Otherwise they may grow long and uneven, causing improper action, undue stress on joints, and broken or cracked hooves. Horses that are worked regularly, especially on hard and stony ground, as well as show horses and race horses in service, must be shod. Shod horses should have their hooves trimmed and their shoes refitted every four to six weeks. Tendency toward unsoundness is probably inherited but may be aggravated by poor hoof care and excessive stresses.

Diseases

Horses are especially susceptible to tetanus or lockjaw but can be given two-year protection through the use of a commonly accepted toxoid. There are two common types of abortion in horses: virus abortion, specifically viral rhinopneumonitis, and the Salmonella type. The former, which produces an influenza with pinkeye, catarrh, general illness, and abortion, affects both mares and foals, but all surviving horses develop natural resistance soon after infection. Pregnant mares thought to be subjected to infection may be given some protection by available vaccines. The Salmonella type of abortion can be prevented completely by vaccination. Encephalomyelitis, or sleeping sickness, is prevented by vaccination. A specific vaccine is available for anthrax, which is prevalent in Asia. Hemolytic anemia of foals has become a problem. Foals so afflicted are born normal but soon become sluggish and progressively weaker; the membranes of their eyes, mouth, and lips become very pale and the heartbeat becomes rapid. This condition is caused by antibodies in the mare's milk that destroy the foal's red blood cells. These antibodies are caused by the difference in blood type between the foal and the mother. Newborn foals can be muzzled to avoid nursing while their blood is checked for reaction against the serum and milk of its mother. Where reactions are noted, the mare is hand-milked at hourly intervals for 12 to 24 hours, and the foal is fed milk from another suitable mare or a milk substitute. Horses are quite susceptible to various infections, but rotation of pastures, strict sanitation, and the use of suitable vermifuges are quite effective.

Buffalo

Camels

The Bactrian camel occurs throughout the highlands of Central Asia from Turkistan to Mongolia and is an important beast of burden throughout that region. The Arabian camel, characteristic of India, the Near East, and North Africa, is likewise primarily important as a beast of burden, though it also provides wool, milk, hides, and meat. It is longer-legged, shorter coated, and more lightly built than the Bactrian camel, standing about seven feet (2.1 metres) tall at the shoulder. In the 19th century camels were introduced to the U.S.–Mexico border regions, the Pacific Northwest, and Australia. The North American experiments were short-lived, but the animals were used in the exploration and development of the Australian outback until about 1940.

Camels can flourish on the coarsest of sparse vegetation, feeding on thorny plants, the leaves and twigs of shrubs, and dried grasses that other animals would refuse, though camels are not averse to more attractive food if it is available. When the feeding is good they accumulate stores of fat in their humps, upon which they are able to draw when conditions are adverse not only for sustenance but also for the manufacture of water by the oxidation of the fat; but they do not store water in the miscalled water cells. They are thus able to fast and go without drinking for several days; they have been known to go without water for 17 days and survive. Other adaptations that enable them to survive in deserts and other unfavourable environments include double rows of heavy protective eyelashes, haired ear openings, the ability to close their nostrils, and keen senses of sight and smell. The female produces one young at a birth after a gestation of 11 months and suckles it for a year; maturity is reached at the age of 10 to 12 years, and the life span is 30 to 40 years.