Learning From Dairy Cattle Selection
USDA research geneticist shares experiences from the dairy industrys use of selection indexes.
BILLINGS, MONTANA (July 8, 2005) Indexes really are the way to go, Paul VanRaden told attendees at the 37th annual Beef Improvement Federation (BIF) annual meeting. VanRaden, a research geneticist with USDA-ARSs Animal Improvement Programs Lab in Beltsville, Md., spoke about the dairy industrys experience with selection indexes, which it has been using since 1971.
Selection indexes are the way to go provided you have accurate data on traits of economic importance, said Paul VanRaden, USDA-ARS Beltsville, while overviewing dairy industry use of indexes.
VanRaden explained that a selection index works by considering multiple traits at once, and, provided you have accurate data on economically relevant traits (ERTs), he said, they can be an effective selection tool.
He cautioned that having accurate evaluations is not the same as knowing what to do with them. With some important traits it is difficult to know which direction to select for, he said, giving examples of selecting for large vs. small cows, or skinny vs. fat cows, high milk volume vs. low volume, etc. In the instance of frame size, he said the showring sometimes dictates selection for large animals, while on-farm production requires a smaller animal, which can lead to a selection quandary. Thus, he said, producers need to know their production goals and select accordingly.
Additionally, VanRaden stressed the importance of subtracting expenses out of indexes. Dont just focus on the income; remember to subtract out expenses, he said, citing feed costs, veterinary expense and death loss as examples.
That said, VanRaden reported that the dairy industry has successfully used selection indexes as a tool for more than 30 years. On an international level, the dairy industry currently maintains a database with information on dairy sires from 25 countries and 27 traits all blended together to form an index on the top merit bulls.
He said this has been a useful tool for dairy producers and reported that a similar international evaluation is being proposed for the beef industry. The program would gather raw data into one pooled analysis for beef sires from around the globe. The proposal is in the early stages. VanRaden said the United States and Australia have not been supportive of the concept, but the International Committee on Animal Recording intends to go ahead with a pooled evaluation, at least for the Charolais and Limousin breeds.
An official published goal helps stimulate economic research and gives breeders direction on which traits are more important, VanRaden concluded. I believe indexes help producers to compete and move their breed ahead. I hope the indexes will be a more accurate solution in the long run.
by Kindra Gordon, field editor, Angus Productions Inc.
© Copyright 2005 Angus Productions Inc.
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