Polygenic hereditary traits of young pigs and their association with the melanocortin receptor gene – 4 (MC4R)

Abstract

The article presents the results of studies of fattening and meat qualities of young pigs of different genealogical lines of large white breed and genotypes by the gene of melanocortin receptor – 4 (MC4R). The research was conducted in “Druzhba-Kaznacheyivka” LLC, the genetics laboratory of the Institute of Pig Breeding and APV NAAS and the animal husbandry laboratory of the State Institution Institute of Grain Crops NAAS. The work was performed according to the research program of NAAS №30 “Innovative technologies of breeding, industrial and organic production of pig products” (“Pig Breeding”). DNA-typing of the melanocortin-4 receptor gene (MC4R) was performed by Kim K., Larsen N., Short T. et al. (2000). Evaluation of young pigs for fattening and meat qualities was carried out taking into account the following quantitative characteristics: the average daily increase in live weight during the period of control fattening, g; age of live weight 100 kg, days; fat thickness at the level of 6–7 thoracic vertebrae, mm; the length of the cooled carcass cm; the length of the bacon half of the cooled half-carcass, cm. The length of the cooled carcass was measured with a measuring tape from the edge of the fusion of the pubic bones to the anterior surface of the first cervical vertebra; the length of the bacon half of the cooled half-carcass - from the anterior edge of the pubic bone to the middle of the anterior edge of the first rib (Berezovsky, Khatko, 2005). Conditions for feeding and keeping young pigs of the experimental groups were identical and complied with zootechnical standards. Economic efficiency of use of animals of various genotypes (МС4RАА, МС4RАG) and biometric processing of the received data (Lakin, 1990). calculated according to generally accepted methods. It is established that young pigs of large white breed of controlled population at the age of reaching live weight of 100 kg exceed the minimum requirements of the elite class by 6.73, fat thickness at the level of 6–7 thoracic vertebrae – 30.84, length of chilled carcass – 3.52 %. Significant difference between animals of different genotypes by melanocortin 4 receptor gene (МС4RАА, МС4RАG) was established by the average daily gain of live weight during the control period of fattening, the age of reaching live weight of 100 kg, fat thickness at the level of 6–7 thoracic vertebrae, length half of the cooled half-carcass and a complex index of fattening and meat qualities (B. Tyler's index). Young pigs of large white breed line Kotilo UA 8819347 outperformed peers line Azuro UA 8800557 on average daily live weight gain during the control period of fattening by 5.29%, the age of 100 kg live weight – 3.29 %, fat thickness at the level of 6–7 breasts vertebrae – 7.14 %. The longer length of chilled carcass (by 1.13 %) and the length of bacon half of chilled half carcass (by 2.68 %) were characterized by animals of Azuro UA 8800557. The correlation coefficient between fattening and meat qualities in young pigs of large white breed of the controlled herd varies ranging from –0.865 (tr = 22.26, P < 0.001) to +0.913 (tr = 35.43, P < 0.001). The maximum increase in additional products was obtained from young pigs of the МС4RАG genotype (+2.57 %) and the genealogical line Kotilo UA 8819347 (+4.86 %), and its cost is +694.26 – 1312.88 UAH/head. in accordance.