The strength of the influence of polymorphism of the kappa-casein and diacylglycerol o-acyltransferase gene polymorphisms on the economically useful qualities of dairy cattle

¹ Kazan State Agrarian University, Kazan, 420015, Russia
² Kazan State Academy of Veterinary Medicine named after N.E.Bauman, Kazan, 420029, Russia
³ FSC food systems named V.M. Gorbatov of the RAS, Moscow, Russia, 109316

^* Corresponding author: tppi-kgau@bk.ru

Abstract

The aim of the work was to study the strength and reliability of the effect of genotypes of kappacasein (CSN3) and diacylglycerol O-acyltransferase (DGAT1) and their complex combination (CSN3/DGAT1) on 12 economically useful traits of black sow cattle. It was found that CSN3 genotype had the greatest reliable effect on the mass fraction of protein in milk in first heifers and high-yielding cows. The share of its influence was η²= 8.9–15.2% (F_fact.= 10.6–12.5; P<0.001). The effect was also found on age at first calving η²= 1.8–2.1% (F_fact.= 3.2–4.2; P<0.05) and milk proteinη²= 4.9% (F_fact.= 3.6; P<0.05) only in first-calving heifers. The DGAT1 genotype significantly (P<0.05–0.001) affected the mass fraction of fat – η²= 10.0–13.2% (F_fact.= 10.6–11.3) and milk protein – η²= 3.2–7.3% (F_fact.= 3.5–5.4), milk fat – η²= 2.9–7.5% (F_fact = 3.1–5.6) и белка – η²= 8.4% (F_fact.= 6.4), milk yield per lactation – η²= 7.6–8.1% (F_fact.= 6.3- 8.7). The milk productivity indicators are more widely influenced by DGAT1 genotype.