Yunhai Li, Huitong Zhou, Long Cheng, Grant R. Edwards & Jonathan G. H. Hickford (2019) Effect of DGAT1 variant (K232A) on milk traits and milk fat composition in outdoor pasture-grazed dairy cattle, New Zealand Journal of Agricultural Research, DOI: 10.1080/00288233.2019.1589537
Yunhai Li, Huitong Zhou, Long Cheng, Grant R. Edwards & Jonathan G. H. Hickford (2019) Effect of DGAT1 variant (K232A) on milk traits and milk fat composition in outdoor pasture-grazed dairy cattle, New Zealand Journal of Agricultural Research, DOI: 10.1080/00288233.2019.1589537
Yunhai Li, Huitong Zhou, Long Cheng, Grant R. Edwards & Jonathan G. H. Hickford (2019) Effect of DGAT1 variant (K232A) on milk traits and milk fat composition in outdoor pasture-grazed dairy cattle, New Zealand Journal of Agricultural Research, DOI: 10.1080/00288233.2019.1589537
Yunhai Li, Huitong Zhou, Long Cheng, Grant R. Edwards & Jonathan G. H. Hickford (2019) Effect of DGAT1 variant (K232A) on milk traits and milk fat composition in outdoor pasture-grazed dairy cattle, New Zealand Journal of Agricultural Research, DOI: 10.1080/00288233.2019.1589537
Abstract
Milk fat production is important in the New Zealand (NZ) dairy industry. Elsewhere, an amino acid substitution (K232A) in the enzyme diacylglycerol acyl-CoA acyltransferase (DGAT1) has been reported to explain variation in some milk traits, including variation in milk fatty acid (FA) profile. In this study, associations between K232A, and milk traits including milk FA composition, were studied in wholly pasture-fed NZ Holstein-Friesian × Jersey (HF×J) cross-bred dairy cows. With a high frequency of K variant (61.9%), the KK cows produced more milk fat than the AA cows (5.41 ± 0.04 % vs 4.42 ± 0.05 %). The milk volume, fat concentration and protein concentration of AK cows were between the genotypes, AA and KK. More C16:0, CLA and C18:3 cis-9, 12, 15 FA were found in the milk of Kiwi-cross cows feed in outdoor pasture grazing system., and the influence of DGAT1 K232A, on these FAs from mid- and late lactation stages were significant. The AA cows produced (P < 0.001) more CLA and C18:3 cis-9, 12, 15, but less C16:0 (1.137 ± 0.047, 0.855 ± 0.015 and 35.170 ± 0.355) than the KK cows (0.934 ± 0.025, 0.778 ± 0.009 and 38.010 ± 0.250).
Biology and Life Sciences, Biochemistry and Molecular Biology
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