![]() Comments About and Examples of Use in Research Some of the terminology used with respect to ruminants is given in Table 15.1ī. Discussions of these and efforts at conservation are described in detail elsewhere (American Livestock Breeds Conservancy, Gibbs et al., 2009). Minor breeds of sheep, goats, and cattle are studied for their genetic and production characteristics. More detailed information regarding these and other ruminant breeds is available (Integrated Taxonomic Information System: ). Of the many beef breeds, the more common in the United States include Angus, Hereford, and Simmental. Holsteins and Brown Swiss have the largest body size, while Jerseys have the smallest. Most breeds of cattle are classified as ‘dairy’ or ‘beef,’ while a few breeds are considered ‘dual-purpose.’ Common dairy breeds in the United States include Holstein (also known as ‘Holstein–Friesian’), Brown Swiss, Jersey, Ayrshire, and Guernsey. Meat breeds include the Boer, Kiko, and Pygmy. ![]() The La Mancha has rudimentary ears that are a genetically dominant distinguishing characteristic of the breed. ![]() Fiber breeds include the Angora and the Cashmere. The Nubian breed was developed from crossbreeding British stock with Egyptian and Indian goats. The major dairy breeds are the Alpine, Nubian, Toggenburg, La Mancha, and Saanen, all of which have origins on the European continent. Goat breeds are numerous and are usually classified according to use as dairy-, meat-, fiber-, or skin-type breeds. Wool breeds include the Merino, Rambouillet, Lincoln, and Romney and are sub-classified according to properties of the wool. Slightly smaller meat breeds include the Southdown and Border Cheviot. ![]() Common breeds raised for meat in the United States include the Dorset, Columbia, Suffolk, and Hampshire. Some breeds are raised for milk (cheese) production. Some wool or hair breeds have varying coat colors. There are many breeds of sheep worldwide that are distinguished as either ‘meat,’ ‘wool,’ or ‘dual’ purpose breeds. Bos indicus, known as Zebu cattle, have a hump over the withers and drooping ears. Bos taurus (domestic cattle) originate from the European continent, and have no hump over the withers. The subgenus Taurus contains all of today’s domestic cattle. The subfamily Bovinae and genus Bos include all domestic and wild cattle, including the yak and Banteng (Bali cattle). Capra hircus is the domestic goat which originated from western Asian goats. The genus and subgenus Ovis includes domestic sheep as well as wild Asian and European sheep species. The subfamily Capra includes sheep and goats. These animals are herbivores, and as adults, derive all their glucose from gluconeogenesis. Members of the Bovidae group of mammals are distinguished by characteristics such as even number of toes, a compartmentalized forestomach, and horns. Sheep, goats, and cattle are ungulates, ‘hooved’ animals that are members of the Order Artiodactyla (animals with cloven hooves), suborder Ruminatia (ruminants or cud-chewing animals) and Family Bovidae. References provided at the end of this chapter and noted in the text offer more information to the interested reader. One chapter is simply not adequate, however, to address the many details and complexities of biology, management, and diseases of these species. ![]() This chapter addresses basic biology, husbandry, and the more common or important diseases of the three ruminant species used most commonly in the laboratory, namely sheep, goats, and cattle. Concern and interest for the welfare for these species and improved understanding of their biology and behavior have continued and are reflected in changing husbandry and management systems. Although ruminants have continued in their traditional agricultural research role, they are now extensively used for studies in molecular biology, genetic engineering and biotechnology for basic science, agricultural, and clinical applications. Formerly large animals were used primarily for agricultural research or as models of human diseases. Since the first edition of this book, the use of ruminants as research subjects has changed dramatically. ![]()
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