Presented results of a study on the relationship of various polymorphic variants of the GH and PIT-1 gene with such economically useful traits as milk yield, milk fat and protein content, the yield of milk protein and fat in highly productive half-sibs of Holstein cows. The experimental animals were divided into groups depending on the combination of different allele forms of the GH and PIT-1 genes. The studies were carried out at ZAO Agro-Soyuz, Dnipropetrovsk region. The total sample сonsisted of 136 half-sibs cows, which were daughters of the Holstein bull Cashmere 131671771. All animals were of the same age. The DNA samples extracted from the experimental animals' blood were subject for the research. To determine the polymorphism of marker genes, the PCR-RFLP method was used. When distributing half-sibs cows on genotypes according to the growth hormone gene GH, were found 124 (91.10%) homozygous animals of LL genotype, 10 (7.50%) heterozygous animals of LV genotype, and 2 (1.40%) homozygous animals of VV genotype. It was established that homozygous half-sibs of LL genotype were dominated over heterozygous half-sibs of LV genotype by milk yield during 303 days for 753 kg (P > 0.99), by the amount of milk fat -for 26.8 kg (P > 0.99), by the amount of milk protein -for 24.7 kg (P > 0.99). An advantage in the main milk productivity indicators of homozygous LL genotype half-sibs of the GH gene over heterozygous LV genotype half-sibs of the GH gene was also observed for 305 days of the second lactation. Heterozygous half-sibs of AB genotype by the PIT-1 gene had an advantage over their peers -homozygous half-sibs of BB genotype, including the milk yield for 425 kg (P > 0.95), the milk fat amount for 16.5 kg (P > 0.95) and the milk protein amount for 14.45 kg (P > 0.99). According to the milk fat and protein content, the difference was not significant. The most pronounced raising effect of the main milk productivity indicators were combinations of GH and PIT-1 paired genes. A part of the complex genotype factor influence on milk yield during 305 days of the first two lactations, the yield of milk fat and protein was about 26.6-30.2% in P> 0.999. The LL homozygosity by the GH gene in combination with the AB and BB genotypes by the PIT-1 gene in the context of the first two lactations was accompanied by higher yield of milk (r = + 0.503 ... 0.505 for P > 0.999), by larger amount of milk fat (r = + 0.503. .. 0.505 for P > 0.999) and milk protein (r = + 0.520 ... 0.530 for P > 0.999). The LL homozygosity by the GH gene in combination with the AB and BB genotypes by the PIT-1 gene in the context of the first two lactations was accompanied by higher yield of milk (r = + 0.503 ... 0.505 for P > 0.999), by larger amount of milk fat (r = + 0.503. .. 0.505 for P > 0.999) and milk protein (r = + 0.520 ... 0.530 for P > 0.999). A statistically significant, direct correlation, average in strength, suggests that the use of genetic markers, in particular GH and PIT-1 genes for growth hormone, will be effective for the selection an...

This study presents the results of the relationship of various polymorphic variants of the GH and PIT-1 gene with the exterior in highly productive Holstein cows. Experimental animals were divided into groups depending on the combination of different allele forms of GH and PIT-1 genes. PCR method was used to determine the polymorphism of marker genes. Isolation of genomic DNA was performed using resin «Chelex-100». The reaction was carried out in a thermal cycler «Tertsyk» made by «DNA technology». The research was carried out in the Private Joint Stock Company «Agro-Soiuz» Dnipropetrovsk region. The total set sample was 48 half-sibling cows, which were the daughters of the Holstein bull Kashemir 131671771. All animals were even-aged analogues. DNA samples isolated from the peripheral blood of the experimental animals were examined. Restrictase AluI was used for the GH gene restriction. After restriction, 171 bp and 52 bp long fragments were detected in representatives of the LL genotype, and a non-restriction fragment with a length of 223 bp was found in carriers of the VV genotype. Restriction of the amplified fragment of RIT-1 gene was performed using restriction endonuclease HinfI. Fragments 660 bp, 425 bp, and 270 bp long, after processing the PCR products with HinfI restriction endonuclease, corresponded to the A allele; fragments 660 bp, 385 bp, and 270 bp long indicated the B allele. Restriction products were separated by electrophoretic method in 2% agarose gel in Tris Borate EDTA. Measurements and exterior indices studies were performed during the 2nd-3d months of the second lactation. It was found that cows of the LL / AB genotype complex compared with their peers of LV/BB and LL/BB genotypes were higher at the withers and sacrum by 3.1 and 2.9 cm, respectively (2.1 and 1.9%; at P > 0, 99). It was determined that the skin in the middle of the last rib of the LL / AB genotype cows compared to peers of LV/BB genotype was thinner by 0.5 mm (9.6%) at P > 0.95. Other measurements of the exterior in the investigated groups of animals differed little. Peers of LL/BB genotype took an intermediate position in these traits. The strength of the complex genotype influence on the features of the exterior was in the range from 2.7 to 12.6%. Holstein cows of the LL/AB genotype had a significant difference in the mass index by 3.3% at P > 0.95, as well as a slightly larger body volume by 28 134.9 cm3 (3.4%), a lower body density index by 0.037 g/cm3 (4.7%) compared with peers of the LV/BB genotype. It is proposed to select animals with the following LL/AB and LL/BB alleles in the complex genotype in order to obtain cows with a better exterior features.

The aim of the study was to research the polymorphism of allelic variants of somatotropin GH genes and pituitary-specific transcription factor PIT-1 and its influence on bioenergetic parameters of high-yielding of Holstein breed cows in intensive milk production technology (cold method of growing heifers, early insemination of heifers. high daily operating loads on the body, etc.). Genotypes of cows were determined by PCR. Blood DNA was examined in a genetic laboratory. Isolation of genomic DNA was performed using resin “Chelex-100”. The reaction was performed in an amplifier “Tertsyk”. For the energy assessment of first-born cows used indicators of net maintenance energy (MJ per day), net milk energy (MJ per day), total net energy consumption (MJ per day), the value of the energy index (the share of energy released from milk, %), productivity index (kilogram of 4 % milk per 1 MJ), net energy consumption per 1 MJ of milk (MJ), energy released with milk per 1 kg of metabolic mass (MJ). The best energy parameters in cows by GH gene – LL genotype, by pituitary-specific transcription factor PIT-1 – AB genotype, and among paired genotypes – LL/AB and LL/BB. In these animals, bioenergetic indicators for the first and second periods of lactation were higher than their peers of LV, BB and LV/BB genotypes by 2.0–15.2 %, with a reliable result for most traits. In particular, during the first lactation period, the advantage of cows of the LL/AB genotype over the LV/BB genotype in terms of bioenergetic indicators was 3.9–15.2 %, significantly less than in the second lactation period in the range of 1.8–7.4 %. In the genome of pituitary-specific transcription factor PIT-1, better bioenergetic parameters were found in cows of genotype AB than in cows of genotype BB. The difference in bioenergetic parameters is explained by the higher lactotropic function of the L and A alleles, and is the result of a greater complementary effect on the functioning of the alleles of the associated genes in the complex genotype. This was confirmed by the analysis of variance of one-factor complexes, which revealed a stronger influence of genotypes on bioenergetic parameters during the first period of lactation than the second. However, the strength of the influence of the paired genotype on the GH and PIT-1 genes was always high regardless of the lactation period and ranged from 8.9 to 20.9 % (P < 0.01–0.001). In the future, it is of interest to study the formation of the exterior and constitution of cows of different genetic influences under the influence of polymorphisms in the GH and PIT-1 genes.