In many areas, genetic diversity should be maintained to help meet the potential challenge resulting from changes in production resources and market requirements. Should anthelmintics become restricted or uneconomical then a breed such as the critically endangered Gulf Coast Native, with the parasite resistance it has developed through natural selection, could be of critical importance in the sheep industry. An example of this type might be the natural resistance some breeds of sheep have to internal parasites. Another example might be an increased need for natural resistance to diseases or parasites should a current antibiotic or other treatment become unavailable or ineffective. In Australia, composite breeds, such as the Australian Friesian Sahiwal, have been developed which have higher milk production levels than Holsteins in the tropical regions of that country. Given these conditions perhaps a breed that is currently rare or endangered, such as the Dutch Belted, which displayed excellent milking ability in a grass-based dairy situation in trials in the early 1900's, would find itself on the forefront. A drastic change in either of these factors could result in a decrease in the advantage of the Holstein. While the Holstein clearly has an advantage over other breeds in the production of whole milk, this advantage is based on feeding high levels of cereal grains and pricing that favors low milk-solids content. Is there a reason for the preservation of minor breeds of livestock? Couldn't more improvement be made if there were fewer breeds? Well, lets go back to our Holstein example again for a moment. Why are we concerned about preserving information about minor, or relatively unknown, breeds of livestock? These animals have, through the centuries, developed a resistance to trypanosomiasis or sleeping sickness spread by the tse-tse fly, which is fatal to most other breeds of cattle. An example of this might be the N'dama cattle from west Africa. Other breeds have traits that result from natural selection pressure based upon the environment in which they were developed. As an example, Holstein cattle have been selected primarily for milk production and are the highest milk producing cattle in the world. In some breeds you can see the amount of change that can occur as the result of selection for a small number of traits. The development of the breeds takes different routes also. Lush's definition it is at least in part the perception of the breeders and the livestock industry which decides when a group of individuals constitutes a "breed". It is their word and the breeders common usage is what we must accept as the correct definition.Īs you can see from Dr. a term which arose among breeders of livestock, created one might say, for their own use, and no one is warranted in assigning to this word a scientific definition and in calling the breeders wrong when they deviate from the formulated definition. Lush helps explain why a good definition of "breed" is elusive.Ī breed is a group of domestic animals, termed such by common consent of the breeders. For example, when is a crossbred animal considered a composite breed and when do we stop thinking about them as composites? Perhaps this definition from The Genetics of Populations by Jay L. Unfortunately this definition leaves some unanswered questions. The classic definition of a "breed" is usually stated as a variation of this statement.Īnimals that, through selection and breeding, have come to resemble one another and pass those traits uniformly to their offspring. We would welcome additional cooperative efforts so please let us know. We already have breeds from every inhabited continent and we have cooperative projects underway with individuals at a number of other Universities to add to our listings and to expand existing information. As time passes we will be expanding the educational and scientific information pertaining to breeds. We see this site as a continually growing resource. We hope you enjoy the information provided and find it both educational and fun. This site is intended as an educational and informational resource on breeds of livestock throughout the world. Welcome to the Breeds of Livestock resource presented by the Department of Animal Science at Oklahoma State University.
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