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 HighWire Citing Articles via Google Scholar Google Scholar Articles by van Vleck, L. D. Search for Related Content PubMed Articles by van Vleck, L. D.

First Lactation Performance and Herd Life

Cornell University, Ithaca, New York

ABSTRACT

Records of artificially sired cows of five breeds having up to five or more lactations were divided into four groups according to first-lactation deviations from herd-mate average. The average deviation for each group in each of four succeeding lactations was greater than for the group which was below it in the first lactation. The fraction of cows having subsequent records was also greater for the groups highest in first-lactation deviations. The pattern was similar for all breeds. The Holstein results showed that more of the high producers (Group 1) in the first lactation had second records than the low producers (Group 4)—82 vs. 61%. More than twice as many had at least five records—32 vs. 15%. The high producers in the first lactation not only continued to outproduce their lower-producing first-lactation mates but also had a substantially longer herd life. These results do not substantiate the claim often made, that high producers in the first lactation burn themselves out and leave the herd at an early age. Actually, these cows appear to stay longer and produce more than their lower-producing first-lactation mates.

This article has been cited by other articles:

				E. Hare, H. D. Norman, and J. R. Wright Survival rates and productive herd life of dairy cattle in the United States. J Dairy Sci, September 1, 2006; 89(9): 3713 - 3720. [Abstract] [Full Text] [PDF]