Abstract

Casein constitutes approximately 80% of the total protein in bovine milk and is regarded as a high-quality dietary protein embracing all the nine essential amino acids. However, the contested physiological effect of a bioactive peptide released upon digestion of a β-casein milk protein variant originating from a cow of a particular genetic makeup has evoked wide interest in research and industry. Present investigations were carried out to genotype the polymorphism in milk β-casein gene, delineate the seasonal, periodic, and parity variations in production and reproduction traits, and examine the genetic association between β-casein genotypes and production, and reproduction traits in Vrindavani crossbred cows. The study revealed that all three types of genotypes viz. A1A1, A2A2 and A1A2 were present in the Vrindavani crossbred population with genotypic frequencies of 12.3%, 39.6% and 48.1% respectively. The least-squares analysis revealed that the season of calving, period of calving, and parity affected several production and reproduction traits of Vrindavani cows significantly. It was found that β–Casein A1/A2 genotype had a significant effect on economic traits viz. LL (p ≤ 0.05), MY/LL (p ≤ 0.05), and Fat% (p ≤ 0.05) in Vrindavani crossbreds. The findings uncover the genetic constitution of the crossbreds for β-casein locus and emphasize its relationship with important economic traits that can aid in devising selection goals.

摘要

酪蛋白约占牛奶中总蛋白质的 80%，被认为是包含所有九种必需氨基酸的优质膳食蛋白质。然而，消化源自具有特定基因组成的奶牛的 β-酪蛋白乳蛋白变体后释放的生物活性肽的有争议的生理效应引起了研究和工业界的广泛兴趣。目前的研究已对牛奶 β-酪蛋白基因的多态性进行了基因分型，描述了生产和繁殖性状的季节性、周期性和胎次变异，并检查了 β-酪蛋白基因型与生产和繁殖性状之间的遗传关联，以及温达瓦尼杂交品种的繁殖性状奶牛。该研究表明，所有三种类型的基因型即。A1A1, A2A2 和 A1A2 存在于 Vrindavani 杂交种群中，基因型频率分别为 12.3%、39.6% 和 48.1%。最小二乘分析表明，产犊季节、产犊期和胎次对温达文奶牛的几个生产和繁殖性状有显着影响。结果发现，β-酪蛋白 A1/A2 基因型对经济性状有显着影响，即。二 （p  ≤  0.05)、MY/LL ( p  ≤  0.05) 和 Vrindavani 杂交品种中的 Fat% ( p  ≤  0.05)。研究结果揭示了 β-酪蛋白基因座杂交品种的遗传构成，并强调了它与有助于制定选择目标的重要经济性状的关系。