Genetic improvement of dairy cattle
Ivar Johansson
Institute of Animal Breeding, The Agricultural College of
Sweden
E-Mail:
Proceedings of the New Zealand Society of Animal Production.
1969, 29: 63-76
The effect of selection depends on (1) the accuracy in the
estimation of the breeding value of individual animals, (2) the
selection differential, (3) the genetic variation in the population, and
(4) the length of the generation interval. The first and second of these
factors can be increased by the breeder and the fourth can be decreased,
thus increasing the selection response per unit of time. The most
powerful tools in dairy breed improvement are an efficient bull progeny
testing of a fairly large number of bulls and an intensive selection
among the tested bulls. The organization of A.I. breeding in Norway is
briefly described. At present it is probably the most efficient scheme
for dairy cattle improvement which has been initiated anywhere.
Keywords: NZSAPAB;
Last Updated 24-08-2000
