Short Communication: Modification of Genetic Evaluation of Herd Life from a Three-Trait to a Five-Trait Model in Canadian Dairy Cattle

• Published in: Journal of dairy science Vol. 90; no. 4; pp. 2025 - 2028
• Main Authors: Sewalem, A., Miglior, F., Kistemaker, G.J., Sullivan, P., Huapaya, G., Van Doormaal, B.J.
• Format: Journal Article
• Language: English
• Published: Savoy, IL Elsevier Inc 01.04.2007; American Dairy Science Association; Am Dairy Sci Assoc
• Subjects: Animal productions; Animals; Biological and medical sciences; body conformation; calving interval; Canada; Cattle - genetics; cattle breeds; culling (animals); dairy cattle; dairy farming; Dairying - methods; fecundity; Female; Food industries; Fundamental and applied biological sciences. Psychology; genetic evaluation; Genetic Variation; herd life; herds; lactation; Lactation - genetics; lactation number; longevity; Longevity - genetics; Male; mammary gland diseases; Milk and cheese industries. Ice creams; milking; Models, Genetic; mortality; multiple-trait animal model; nonreturn rate; simulation models; somatic cell count; Terrestrial animal productions; udders; Vertebrates; Canada; herd life; longevity; multiple-trait animal model; genetic evaluation; Evaluation; Modification; Animal model; Dairy cattle; Longevity; Herd; Vertebrata; Mammalia; Dairy industry; Genetics; Artiodactyla; Ungulata
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2006-719

The national genetic evaluation of herd life for Canadian dairy breeds was modified from a 3-trait to a 5-trait animal model. The genetic evaluation incorporates information from daughter survival (direct herd life) and information from conformation, fertility, and udder health traits that are related to longevity (indirect herd life). Genetic evaluations for direct herd life were based on cows’ survival from first calving to 120 days in milk (DIM), from 120 to 240 DIM, from 240 DIM to second calving, survival to third calving, and survival to fourth calving, which were analyzed using a multiple-trait animal model. Sire evaluations obtained for each of the 5 survival traits were combined into an overall sire evaluation for direct herd life. Sire evaluations for indirect herd life were based on an index of sire evaluations for dairy strength, feet and legs, overall mammary, rump angle, somatic cell score, milking speed, nonreturn rate in cows, and interval from calving to first service. A multiple-trait sire model based on multiple-trait across-country evaluation methodology was used to combine direct and indirect genetic evaluations for herd life into an overall genetic evaluation for herd life. Sire evaluations for herd life were expressed as an estimated transmitting ability for the number of lactations. The transmitting ability represents expected differences among daughters for herd life; and the average herd life was set to 3 lactations.