Abstract

In recent years, the aim of dairy cattle breeding was to increase milk productivity traits. However, there is an observed decrease of fertility traits of cows, and, as a result, early culling of animals. This is due to the fact that causes of decreased reproduction are sometimes impossible to determine and its signs are difficult to estimate. One of the causes for decreasing fertility of cows is the decline in the quality of oocytes capable of fertilization. Therefore, a study into the ratio between the number and quality of oocytes capable of fertilization and the level of milk productivity in cows, as well as association with polymorphic variants of the GH, PRL, and Pit-1 genes, is of scientific interest. The aim of this study was to determine the dependence of the quality and quantity of cow COC obtained post mortem on the level of milk productivity and genetic profile for the genes GH, PRL, and Pit-1. There was high frequency of allele L of the GH gene, 0.942; allele A of the PRL gene, 0.889; and allele B of the Pit-1 gene, 0.710. High average content of COC per ovary was obtained in a group of animals with LL genotype of the GH gene (LL to LV +7.54 units, p ≤ 0.05), and a significant portion of them were viable (LL to LV +4.5 units, p ≤ 0.05). In individuals with the AA genotype of the PRL gene, the average number of isolated viable COC per ovary was higher than in those with the AB genotype (+4.84 units, p ≤ 0.05). Analysis of the association of polymorphic variants of the Pit-1 gene with the quantity and quality of COC did not reveal significant differences in the studied group of individuals. Assessment for the relationship of polymorphic variants of the studied genes with the breeding value (BV) indices of milk productivity, milk fat, and protein content showed that only animals with the LV genotype exceeded their peers with the LL genotype of the GH gene in milk fat and protein content by 8.3 kg (p ≤ 0.05) and 6.0 kg (p ≤ 0.01), respectively. Average calculated breeding value based on quantity of COC of individuals in the studied groups revealed no significant difference.

中文翻译：

---

奶牛卵母细胞复合体形态的基因Gh，Prl和Pit-1多态性变异与奶牛生产力的联系

摘要

近年来，奶牛育种的目的是提高牛奶生产率。但是，观察到奶牛的生育性状下降，因此，动物被早期淘汰。这是由于这样的事实，有时无法确定繁殖减少的原因，并且其迹象难以估计。降低母牛生育能力的原因之一是能够受精的卵母细胞质量下降。因此，对具有受精能力的卵母细胞的数量和质量与奶牛生产力水平之间的比率以及与GH，PRL和Pit-1基因的多态性变体的关联进行研究具有科学意义。GH，PRL和Pit-1。GH基因的L等位基因L频率很高，为0.942；PRL基因的等位基因A ，0.889；Pit-1基因的等位基因B为0.710。一组动物中得到每卵巢COC的高平均含量与所述的LL基因型GH基因（LL到LV 7.54单位，p ≤0.05），和它们的显著部分是存活的（LL到LV 4.5单位，p ≤0.05）。在具有PRL基因的AA基因型的个体中，每个卵巢中分离出的存活COC的平均数高于具有AB基因型的个体（+4.84个单位，p≤0.05）。Pit-1基因的多态性变异与COC的数量和质量的关联性分析未显示研究组中的显着差异。评估研究基因的多态性变体与牛奶生产力，牛奶脂肪和蛋白质含量的育种值（BV）指数之间的关系后，发现只有LV基因型的动物超过了牛奶中GH基因的LL基因型的同龄动物脂肪和8.3公斤（蛋白质含量p ≤0.05）和6.0公斤（p分别≤0.01）。在研究组中，基于个体的COC数量计算的平均育种值没有显着差异。