J. B. Cole J. B. Cole 1 , P. D. Miller , P. D. Miller 2 , and H. , and H. D. Norman D. Norman 1 1 Animal Improvement Programs Laboratory Agricultural Research Service, USDA, Beltsville, MD 2 Department of Dairy Science University of Wisconsin-Madison, Madison, WI 2004 Genetic Improvement of Dairy Cattle Health
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J. B. Cole 1, P. D. Miller 2, and H. D. Norman 1 1 Animal Improvement Programs Laboratory Agricultural Research Service, USDA, Beltsville, MD 2 Department.
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J. B. ColeJ. B. Cole11, P. D. Miller, P. D. Miller22, and H. D. Norman, and H. D. Norman11
1Animal Improvement Programs Laboratory Agricultural Research Service, USDA, Beltsville, MD2Department of Dairy Science University of Wisconsin-Madison, Madison, WI
2004
Genetic Improvement of Dairy Cattle Health
Genetic Improvement of Dairy Cattle Health John B. Cole2004
OverviewOverview
• Response to selection using field-recorded traits is efficient and well-documented.
• Herd owners are interested in healthy, longer-lived cows.
• Genetic variability exists for health traits of economic interest.
Genetic Improvement of Dairy Cattle Health John B. Cole2004
OverviewOverview
• Statistical and computational tools for genetic evaluation exist.
• Data processing routines can be developed.
• However, data needed for routine evaluations are limited.
Genetic Improvement of Dairy Cattle Health John B. Cole2004
Why select for improved health?Why select for improved health?
• Longer-lived (more profitable) cows.
• Decreased cost of production.
• Reduced herd turnover.
• Improved animal welfare.
• Genetic gains are cumulative!
Genetic Improvement of Dairy Cattle Health John B. Cole2004
Desirable Properties of Health TraitsDesirable Properties of Health Traits
• Reasonably large genetic variability or heritability.
• Significant economic value.
• Reasonable cost of measurement and recording.
• Consistent methods for measurement and recording.
(Shook, 1989)
Genetic Improvement of Dairy Cattle Health John B. Cole2004
ChallengesChallenges
• Low heritabilities for some traits.
• Unfavorable correlations with milk, fat, and protein yield.
• Affected animals have a low frequency of occurrence.
• Diagnoses may be uncertain.
• Data are not collected in a national database.
Genetic Improvement of Dairy Cattle Health John B. Cole2004
Heritabilities and Correlations of Heritabilities and Correlations of Composite Health TraitsComposite Health Traits