Preferred and undesirable genotypes of bGH and bIGF-1 genes for the milk yield and quality of black-and-white breed

Abstract

Background and Aim: The market demand for the quality of milk and dairy products, in particular in terms of such indicators as fat content, the amount and composition of milk protein, etc., is growing. Thus, the need for the selection of dairy herds using genetic markers associated with qualitative traits of milk productivity is becoming urgent. This study aimed to determine the preferred and undesirable genotypes of the AluI polymorphism of the growth hormone gene and SnaBI polymorphism of the insulin-like growth factor-1 gene associated with milk productivity and quality indicators of the black-and-white breed. The genotypes of animals were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Materials and Methods: Samples of the black-and-white breed from Kazakhstan served as the research subjects. The polymorphism of the growth hormone and insulin-like growth factor-1 genes was determined by PCR-RFLP. The relationship of bGH-AluI and bIGF-1-SnaBI polymorphisms with productivity was assessed (fat, protein, and milk yield for 305 days of lactation, live weight, somatic cells, and milk production coefficient) by analysis of variance using Statistica 6.0 software. Results: The black-and-white cows with the bGH-AluILV genotype had significantly higher milk yield in 305 days (3174.5±157.2 kg) than those with the bGH-AluILL (2940.0±152.6 kg) and bGH-AluIVV genotypes (2964.0±36.0; p<0.05). The milk fat content of cows with genotypes bGH-AluILV and bGH-AluILL (121.8±6.5 and 120.6±10.2, respectively) was significantly higher than those with bGH-AluIVV genotype (109.8±10.8; p<0.05). The black-and-white cows with the bGH-AluILV genotype (96.7±5.3) had significantly more milk protein than those with the bGH-AluILL (90.3±5.6) and bGH-AluIVV (86.9±4.6) genotypes (p<0.05). There were no statistically significant differences in the indicators of milk productivity of cows with different genotypes of bIGF-1-SnaBI polymorphism. Conclusion: The results showed that the bGH-AluILV genotype was preferred for the black-and-white breed. The study demonstrated that genotype determined the relevant qualities, while the conditions of feeding, maintenance, and industrial technology provided the manifestation of this genotype. Thus, cows of the same (Wis Burke Ideal) line, having common ancestors in close (IV–V) ranks but living in different farming conditions, had large differences in milk productivity level. The variation was 2046 kg or 67.6% of milk per lactation.

Effects of Somatotropic Axis Gene Polymorphisms on Milk Yields in Simmental Cattle

“…(Zhou et al, 2006;Maylinda, 2011;Moravcikova et al, 2012;Hazuchova et al, 2013). Studies conducted on different cattle types and buffaloes have reported that GH-AluI gene polymorphisms affect meat yield, pre-slaughter body weight, carcass meat weight, slaughter weight and growth data (Pereira et al, 2005;Curi et al, 2006;Sedykh et al, 2020;El-Komy et al, 2021) Parallel to our research, polymorphic association studies analyzing somatotropic axis genes together have generally associated these genes with growth and reproduction data but not with milk yield, especially GH/AluI and IGFI/SnaBI (Balogh et al, 2008;Ulyanov et al, 2021). The two different META analysis studies show that the common L allele was dominant and no significant difference was found in the results of the meta-analysis and subgroup analysis for the milk yields in the LL, LV, and VV genotypes Akcay et al, 2020;Bangar et al, 2021).…”

Determination of Diplotypes Associated with Meat Productivity in Cattle Breeds Common in the Territory of the Republic of Kazakhstan

“…The nucleotide sequence polymorphism of the insulinlike growth factor-1 gene bIGF-1 in the P1 promoter region was identified by Hines H.C. (Ulyanov et al, 2021). Amplified PCR products of the bovine bIGF-1 gene (249 bp) were digested using the restriction enzyme SnaBI.…”

Phenotypic and genotypic resistance to antibiotics in Staphylococcus aureus strains isolated from cattle milk in Northern Kazakhstan

“…One of the main sectors of the Kazakh economy is animal husbandry, in which dairy farming plays an important role [ 11 ]. In Kazakh farms, between 20% and 40% of cows are infected with mastitis [ 12 ].…”