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United States Department of Agriculture

Agricultural Research Service

Title: Genetic Evaluation of Dairy Goats for Yield and Type

Authors
item Wiggans, George
item Hubbard, Suzanne
item Wright, Janice

Submitted to: Extension Goat Industry Handbook
Publication Type: Government Publication
Publication Acceptance Date: August 27, 1999
Publication Date: N/A

Interpretive Summary: To select genetically superior animals as parents, breeders must have accurate information on the genetic merit of their animals. Genetic evaluations of dairy goats (Alpines, Experimentals, LaManchas, Nubians, Oberhaslis, Saanens, and Toggenburgs and crossbred animals) have been developed from yield data collected through the National Cooperative Dairy Herd Improvement Program and from type (conformation) and pedigree data supplied by the American Dairy Goat Association (ADGA). Yield evaluations are calculated for milk, fat, and protein yields and component percentages; an index for milk, fat, and protein (MFP$) is calculated based on economic values for dairy cattle. Yield evaluations in July 1998 included 198,698 does and 43,763 bucks, of which 9,075 bucks had at least 5 daughters. Type evaluations are calculated for 13 linear type traits (stature, strength, dairyness, rump angle, rump width, rear legs, fore udder attachment, rear udder height, rear udder arch, medial suspensory ligament, udder depth, teat placement, and teat diameter) and final score. Evaluations for final score in November 1997 included 57,224 does and 19,135 bucks, of which 1,612 bucks had at least 5 daughters. Two production-type indexes are computed by ADGA with 2:1 and 1:2 weightings for MFP$ and predicted transmitting ability for final score. Genetic evaluations of dairy goats are released annually (July for yield, November for type) to the dairy goat industry by USDA. Evaluations are available to producers through ADGA or a USDA web site (http://aipl.arsusda.gov). Use of accurate, reliable genetic evaluations can lead to genetic improvement of dairy goats for traits of economic interest to breeders and producers.

Technical Abstract: Genetic evaluations of dairy goats (Alpines, Experimentals, LaManchas, Nubians, Oberhaslis, Saanens, and Toggenburgs and crossbred animals) are computed annually by USDA from yield data collected through the National Cooperative Dairy Herd Improvement Program and from type and pedigree data supplied by the American Dairy Goat Association (ADGA). Yield evaluations in July 1998 included 198,698 does and 43,763 bucks, of which 9,075 bucks had at least 5 daughters; evaluations for final score in November 1997 included 57,224 does and 19,135 bucks, of which 1,612 bucks had at least 5 daughters. For yield evaluation, an animal model similar to that for dairy cattle is used, but analysis is across breeds. Lactation records for the first 6 lactations of does born since July 1973 and kidding since Jan. 1976 are edited with limits appropriate for goats, projected to 305 days, and adjusted for kidding age and month. Evaluations are computed for milk, fat, and protein yields and component percentages; an index for milk, fat, and protein (MFP$) is calculated based on economic values for dairy cattle. For type evaluation, a multitrait animal model is applied across breeds to 13 linear type traits (stature, strength, dairyness, rump angle, rump width, rear legs, fore udder attachment, rear udder height, rear udder arch, medial suspensory ligament, udder depth, teat placement, and teat diameter) and final score. Type records are adjusted for a doe's age at appraisal, and all appraisals for a doe are included in genetic evaluations. Two production-type indexes are computed by ADGA with 2:1 and 1:2 weightings for MFP$ and predicted transmitting ability for final score.

Last Modified: 7/30/2014
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