Effects of milkfat yield and conformation traits on retention
for a second lactation of Friesian and Jersey-sired cows
G. Ahlborn-Breier and B.W. Wickham
Livestock Improvement Division, New Zealand Dairy Board,
Hamilton
Proceedings of the New Zealand Society of Animal Production.
1986, 46: 83-86
The relative importance of the currently recorded large number
of descriptive conformation traits and of milkfat yield on retention for
a second lactation of 6645 Friesian-sired and 5709 Jersey-sired heifers
was examined. In a linear multiple regression model, the effect of
heifers deviating from the 'normal' conformation for a certain trait on
the retention rate was used as an indicator for the relative importance
of the trait. Milkfat yield was by far the most important trait for
both breeds. Only a small number of conformation traits describing
udder and teats influenced the retention rate significantly. The farmer
with Jersey cows appeared to consider more conformation traits as
important than the owner of Friesian cows. The results suggest the
inclusion of only the important conformation traits describing udder and
teats as potential traits in the selection of profitable dairy cattle in
New Zealand to retain a high genetic response for milkfat yield.
Keywords: NZSAPAB;
Conformation; milkfat yield; Friesian; Jersey; stayability;
survival rate; linear multiple regression; pasture based production
system
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Last Updated 18-03-1997
