Author:
Meyer Karin,Brotherstone Susan,Hill W. G.,Edwards Maureen R.
Abstract
ABSTRACTRecords on 18 939 Friesian-Holstein cows classified for 16 linear-type traits and total score in first lactation by the British Friesian Cattle Society and similarly on 13 192 cows in second lactation were analysed to estimate heritabilities and genetic correlations among the linear traits. These comprised progeny of 542 and 477 young sires, respectively, together with older sires included to increase connections. Correlations of type with milk production traits and correlations between type in first and second lactations were estimated from subsets (of about one-half) of the data. Effects due to proportion of Holstein in the sires were removed.Heritabilities of the linear traits were similar in first and second lactations, ranging from under 0·15 for one of the leg traits to about 0·5 for stature. Genetic correlations between traits in first and second lactation were generally over 0·75, whereas phenotypic correlations for most traits ranged from 0·3 to 0·6. Genetic and phenotypic correlations among the linear traits were generally low, except for those involving size.Phenotypic correlations between linear traits and milk yield and composition were all small, none exceeding 0·3. Genetic correlations were generally almost as small: taking first and second lactations together, the only consistent non-negligible correlations with yield were for angularity (+0·3), fore-udder attachment (–0·2) and udder depth (–0·4). The linear traits are not useful predictors of yield.
Publisher
Cambridge University Press (CUP)
Subject
Animal Science and Zoology
Reference17 articles.
1. Evaluation of a Linearized Type Appraisal System for Holstein Cattle
2. Recovery of inter-block information when block sizes are unequal
3. Inheritance of type characteristics;Shill;British Friesian Journal,1983
4. Maximum likelihood from incomplete data with the EM algorithm;Dempster;Journal of the Royal Statistical Society,1977
5. Evaluation of a Linear Type Program in Holsteins
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