JDS Track the topics, authors and articles important to you
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]
Author:
Keyword(s):
Year:  Vol:  Page: 


Reprint (PDF) Version of this Article
Similar articles found in:
JDS Online
PubMed
PubMed Citation
This Article has been cited by:
other online articles
Search PubMed for articles by:
Wiggans, G. R. || Zuurbier, J.
Alert me when:
new articles cite this article
Download to Citation Manager

Journal of Dairy Science, Vol 78, Issue 7 1584-1590, Copyright 1995 by American Dairy Science Association


JOURNAL ARTICLE

Calculation and use of inbreeding coefficients for genetic evaluation of United States dairy cattle

G. R. Wiggans, P. M. VanRaden and J. Zuurbier
Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705-2350, USA.

Inbreeding coefficients are calculated routinely for all animals included in national genetic evaluations for yield traits. The base population for inbreeding is defined as animals born during 1960. Animals with unknown parents are assumed to have inbreeding coefficients that are equal to the mean of coefficients for animals with known parents born during the same year. Mean inbreeding coefficients reached .03 to .04 for recent years, and coefficients for some animals exceeded .50. The annual increase in level of inbreeding was highest for Milking Shorthorns, but the rate of change of that increase was greatest for Holsteins. Accounting for inbreeding in calculation of the inverse of the relationship matrix had only a small effect on evaluations. For Jersey, the maximum change in breeding value was 73 kg of milk for cows and 40 kg of milk for bulls with > or = 10 daughters. Estimates of inbreeding depression were similar across breeds for production traits and were -29.6 kg of milk, -1.08 kg of fat, and -.97 kg of protein per 1% of inbreeding for Holsteins. In January 1994, the USDA began considering the percentage of inbreeding when calculating inverses of relationship matrices, the largest matrix representing over 20 million Holsteins; this inbreeding percentage was released to the dairy industry for bulls.

This article has been cited by other articles:


Home page
J Dairy SciHome page
B. G. Cassell, V. Adamec, and R. E. Pearson
Effect of Incomplete Pedigrees on Estimates of Inbreeding and Inbreeding Depression for Days to First Service and Summit Milk Yield in Holsteins and Jerseys
J Dairy Sci, September 1, 2003; 86(9): 2967 - 2976.
[Abstract] [Full Text] [PDF]


Home page
J Dairy SciHome page
P. M. VanRaden and A. H. Sanders
Economic Merit of Crossbred and Purebred US Dairy Cattle
J Dairy Sci, March 1, 2003; 86(3): 1036 - 1044.
[Abstract] [Full Text] [PDF]


Home page
J Dairy SciHome page
P. R. Tozer and J. R. Stokes
Producer Breeding Objectives and Optimal Sire Selection
J Dairy Sci, December 1, 2002; 85(12): 3518 - 3525.
[Abstract] [Full Text] [PDF]





HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright 1995 by the American Dairy Science Association.