Associations between the K232A polymorphism in the diacylglycerol-O-transferase 1 (DGAT1) gene and performance in Irish Holstein-Friesian dairy cattle
Year: 2010
Type: other
Abstract: Selection based on genetic polymorphisms requires accurate quantification of the\neffect or association of the polymorphisms with all traits of economic importance.\nThe objective of this study was to estimate, using progeny performance data on 848\nHolstein-Friesian bulls, the association between a non-conservative alanine to lysine\namino acid change (K232A) in exon 8 of the diacylglycerol-O-transferase 1 (DGAT1)\ngene and milk production and functionality in the Irish Holstein-Friesian population.\nThe DGAT1 gene encodes the diacylglycerol-O-transferase microsomal enzyme\nnecessary to catalyze the final step in triglyceride synthesis. Weighted mixed model\nmethodology, accounting for the additive genetic relationships among animals, was\nused to evaluate the association between performance and the K232A polymorphism.\nThe minor allele frequency (K allele) was 0.32. One copy of the K allele was associated\n(P < 0.001) with 77 kg less milk yield, 4.22 kg more fat yield, 0.99 kg less protein\nyield, and 1.30 and 0.28 g/kg greater milk fat and protein concentration, respectively;\nall traits were based on predicted 305-day production across the first five lactations.\nThe K232A polymorphism explained 4.8%, 10.3% and 1.0% of the genetic variance in\nmilk yield, fat yield and protein yield, respectively. There was no association between\nthe K232A polymorphism and fertility, functional survival, calving performance,\ncarcass traits, or any conformation trait with the exception of rump width and carcass\nconformation. Using the current economic values for the milk production traits\nin the Irish total merit index, one copy of the K allele is worth €5.43 in expected\nprofitability of progeny. Results from this study will be useful in quantifying the\ncost-benefit of including the K232A polymorphism in the Irish national breeding programme.
Language: English
Subfield: Genetics
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2169612975