Abstract

The relevance of the survey is to explore the selection approaches to increasing the mass fraction of protein and its biological value in the milk produced by Black-and-White cows. The objective of the survey is to study the amino-acid composition and the biological value of protein in the milk produced by Black-and-White cows and their respective crosses with Montbeliarde in order to identify the prospects for this breed in the Black-and-White commercial herds. It was ascertained that the mass fraction of protein in milk of the half-blood crosses (1/2 MB × 1/2 BW) made up 3.50%, which was 0.26% higher than that in their Black-and-White peers. Despite full ranges and almost equal proportions of essential amino acids in the milk protein of crossbred and purebred cows, comprising 48.0% each, the crosses tended to have significantly higher contents of both the essential amino acids—isoleucine, lysine, tyrosine, and threonine—except an inferior concentration of tryptophan and the nonessential amino acids: alanine, arginine, and aspartic acid + asparagine. The results provide a profound basis for the evidence to recommend the use of Montbeliarde cows in the Black-and-White commercial herds in order to increase the mass fraction of milk protein and to improve its amino acid composition.

中文翻译：

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白奶牛和黑奶牛及其与蒙贝利亚尔杂交的蛋白质的氨基酸组成和蛋白质生物学价值

摘要

该调查的相关性是探索选择方法，以增加黑白奶牛生产的牛奶中蛋白质的质量分数及其生物学价值。该调查的目的是研究黑白奶牛及其与Montbeliarde杂交的奶中氨基酸的组成和蛋白质的生物学价值，以便确定该品种在黑白奶牛中的前景。 -白色的商业畜群。可以确定，半血杂交（1/2 MB×1/2 BW）的牛奶中蛋白质的质量分数为3.50％，比黑白同类动物的蛋白质质量分数高0.26％。尽管杂种和纯种奶牛的乳蛋白中的必需氨基酸范围广泛且几乎相等，但各占48.0％，除色氨酸和非必需氨基酸（丙氨酸，精氨酸和天冬氨酸+天冬酰胺）的浓度较低外，这些十字架的必需氨基酸（异亮氨酸，赖氨酸，酪氨酸和苏氨酸）的含量往往明显较高。该结果为推荐在黑白商业畜群中使用Montbeliarde奶牛以增加乳蛋白的质量分数并改善其氨基酸组成的证据提供了深刻的基础。