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Genetic correlations between 305-day and monthly test day milk yield records in primiparous Iranian Holsteins

Published online by Cambridge University Press:  20 November 2017

H. Farhangfar ,
P. Rowlinson  and
M.B. Willis
H. Farhangfar
Affiliation:
Department of Agriculture, University of Newcastle upon Tyne, NE1 7RU, U.K.
P. Rowlinson
Affiliation:
Department of Agriculture, University of Newcastle upon Tyne, NE1 7RU, U.K.
M.B. Willis
Affiliation:
Department of Agriculture, University of Newcastle upon Tyne, NE1 7RU, U.K.
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Extract

Traditionally, in most dairy cattle breeding programmes genetic evaluation of dairy sires and cows has been primarily based on 305-day lactation yield. To provide 305-day lactation yields many partial lactations have to be extended by adjustment factors resulting in overestimation or underestimation of 305-day yields which in turn leads to biased prediction of breeding values. Over the past decade there has been a considerable interest in using monthly test day records instead of 305-day lactation yield to predict breeding values of dairy cattle as early as possible and also to increase genetic gain through reducing generation interval. The main objective of present research was to estimate the genetic correlations between 305-day and monthly test day milk yields in Iranian Holstein dairy heifers.

Type
Poster Presentations
Information
Proceedings of the British Society of Animal Science , Volume 2001 , 2001 , pp. 219
Copyright
Copyright © The British Society of Animal Science 2001

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References

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