Feeding and meat qualities of young pigs of different genotypes according to melanocortin 4 receptor (Mc4r) gene and interbreed differentiation according to the coefficient of decrease in growth intensity in early ontogenesis

The paper presents the results of studies of fattening and meat qualities of young large white pigs of different genotypes for the melanocortin receptor 4 (Mc4r) gene and the decline in growth intensity in early ontogeny. The research was carried out in the agricultural formations of the Dnipropetrovsk region, the Jazz meat processing plant, the laboratory of the genetics of the Institute of Pig Breeding and APV of the National Academy of Sciences, and the laboratory of animal husbandry of the State Institution “Institute of Grain Crops of the National Academy of Sciences”. The work was carried out following the scientific research program of the National Academy of Sciences No. 30, “Innovative technologies of breeding, industrial and organic production of pig farming products” (“Pig farming”). Assessment of animals for fattening and meat quality was carried out taking into account the following characteristics: average daily gain of live weight during the period of control fattening, g; the age of reaching 100 kg live weight, days, length of the chilled carcass, cm; length of the bacon half of the cooled carcass, cm; thickness of lard at the level of 6–7 thoracic vertebrae, mm. The coefficient of decline in growth intensity was calculated according to the method of Yu. K. Sviechin. Biometric research results were processed using generally accepted methods. It was established that according to live weight at 4 and 6 months of age, fattening and meat qualities (age of reaching a live weight of 100 kg, days; lard thickness at the level of 6–7 thoracic vertebrae, mm; length of the chilled carcass, cm) young pigs the controlled population belongs to the I class and the elite class. The coefficient of growth decline in animals of the controlled population ranges from 108.57 to 142.51 points. The data analysis shows that according to the live weight at 4 and 6 months of age, the age of reaching the live weight of 100 kg, the fat thickness at the level of 6–7 thoracic vertebrae, and the length of the chilled carcass, the young pigs of the controlled population belong to the I class and the elite class. Animals of the Mc4r АГ genotype prevail over peers of the Mc4r AA genotype in terms of fattening and meat qualities by an average of 5.90 %. The interbreed differentiation of young pigs by the coefficient of the intensity of growth decline (∆K) shows that the difference between the animals of the experimental groups in terms of the average daily gain in live weight is 23.3 g (td = 2.62), the age of reaching 100 kg live weight is 2.7 days (td = 1.59), the length of the cooled carcass is 1.4 mm (td = 2.12). The number of reliable correlations between fattening and meat qualities, coefficient of the intensity of growth decline (∆K), and Tyler B. index is 75.0 %, which indicates the possibility of their use in selection and breeding work. The use of young pigs of the Mc4r АG genotype and animals of the I group, in which the coefficient of the intensity of growth decline (∆K) ranges from 115.61 to 123.27 points, provides additional production at the level of +3.68 – +1.75 % respectively.