HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kennedy, B. W. Articles by Moxley, J. E. Search for Related Content PubMed Articles by Kennedy, B. W. Articles by Moxley, J. E.

Genetic Trends Among Artificially Bred Holsteins in Quebec

Dairy Herd Analysis Service, Macdonald College, Ste-Anne de Bellevue, Quebec, Canada HOA 1C0

ABSTRACT

Mixed-model methods were used to evaluate 52 Holstein sires in artificial insemination for milk, fat, and protein yield and fat and protein percent. A total of 3288 305-day first lactations of Holstein on the Dairy Herd Analysis Service were studied. Sires were grouped by year of first service, and groups were used to measure trends in the average generic merit of sires sampled. Annual genetic trends among sires were 85, 1.4, and 1.0 kg for milk, fat, and protein yield and kg for milk, fat, and protein yield and –.029 and –.031% for fat and protein test. Genetic trends among their daughters were estimated for Quebec herds according to relative sire usage. Trends in yields were positive. Average yearly genetic gains for milk, fat, and protein yield were 46, 1.1 and .5 kg for all herds and 57, 1.9, and 1.1 kg for herds in Analysis Service. Trends for milk composition were negative. Annual genetic declines in fat and protein percent were –.004 and –.008% for the population and –.003 and –.014% for herds in Analysis Service.