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Genetic parameters of milk production traits and fatty acid contents in milk for H olstein cows in parity 1 – 3
Author(s) -
Bastin C.,
Soyeurt H.,
Gengler N.
Publication year - 2013
Publication title -
journal of animal breeding and genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.689
H-Index - 51
eISSN - 1439-0388
pISSN - 0931-2668
DOI - 10.1111/jbg.12010
Subject(s) - heritability , parity (physics) , biology , genetic correlation , zoology , fatty acid , trait , milk protein , food science , genetic variation , genetics , gene , biochemistry , physics , particle physics , computer science , programming language
Summary The objective of this study was to estimate genetic parameters of milk, fat, and protein yields, fat and protein contents, somatic cell count, and 17 groups and individual milk fatty acid ( FA ) contents predicted by mid‐infrared spectrometry for first‐, second‐ and third‐parity H olstein cows. Edited data included records collected in the W alloon region of B elgium from 37 768 cows in parity 1, 22 566 cows in parity 2 and 8221 in parity 3. A total of 69 (23 traits for three parities) single‐trait random regression animal test‐day models were run. Approximate genetic correlations among traits were inferred from pairwise regressions among estimated breeding values of cow having observations. Heritability and genetic correlation estimates from this study reflected the origins of FA : de novo synthetized or originating from the diet and the body fat mobilization. Averaged daily heritabilities of FA contents in milk ranged between 0.18 and 0.47. Average daily genetic correlations (averaged across days in milk and parities) among groups and individual FA contents in milk ranged between 0.31 and 0.99. The genetic variability of FA s in combination with the moderate to high heritabilities indicated that FA contents in milk could be changed by genetic selection; however, desirable direction of change in these traits remains unclear and should be defined with respect to all issues of importance related to milk FA .