Comparisons of cows and herds in two progeny testing programs and two corresponding states

Citation
Cn. Vierhout et al., Comparisons of cows and herds in two progeny testing programs and two corresponding states, J DAIRY SCI, 82(4), 1999, pp. 822-828
Citations number
13
Categorie Soggetti
Food Science/Nutrition
Journal title
JOURNAL OF DAIRY SCIENCE
ISSN journal
00220302 → ACNP
Volume
82
Issue
4
Year of publication
1999
Pages
822 - 828
Database
ISI
SICI code
0022-0302(199904)82:4<822:COCAHI>2.0.ZU;2-T
Abstract
Data were USDA genetic evaluations of cows and DHI herd profiles from 4154 Holstein progeny-test herds from two artificial insemination organizations, 21st Century Genetics (Shawano, WI) and Genex (Ithaca, NY), and from 6361 additional herds from Minnesota and New York. We grouped herds into four ca tegories: 21st Century Genetics herds, other Minnesota herds, Genex herds, and other New York herds. Herds were eliminated if they contributed fewer t han 10 cows with genetic evaluations and birth dates from January 1989 to M arch 1995. Data included 83 and 74%, respectively, of first-crop daughters of 21st Century Genetics and Genex progeny-test bulls with genetic evaluati ons from January 1995 to February 1997. Herds were characterized by DHI pro file and cow evaluation data. Daughters of progeny-test bulls with extreme production records (outside of 3 SD) relative to herd mean and variance did not appear in disproportionate numbers among the progeny of bulls likely c ulled or considered for further use. The two organizations appear to have s elected larger, genetically superior, and better managed herds from within their respective regions for progeny-testing purposes. We were not able to predict whether a bull in the progeny-testing programs of these two organiz ations was going to exceed or fail to meet the pedigree prediction from cha racteristics of herds in which his daughters performed. Differences between parent average and daughter yield deviations for typical young sires appea r to result from Mendelian segregation of genes.