The influence of genotype and feeding level of gilts on their further reproductive performance

Since the efficiency of pig breeding largely depends on the reproductive ability of sows, one of the promising areas of research in animal husbandry is the study of factors whose correction can improve the fertility and quality of the offspring. Our work purpose was to investigate the effect of gilts’ feeding level, MC4R genotype and interaction of these factors on the reproductive traits pigs after reaching puberty. The object of the study was crossbred pigs obtained as a result of the combination of sows of the Large White breed with boars of the Landrace breed. To carry out the research, the animals were divided into four groups that differed among themselves by the genotype of the melanocortin 4 receptor gene and the level of feeding of the experimental animals. To determine the genotype, the PCR-RFLP method was utilized. Genetic studies were conducted in a certified laboratory of the Institute of Pig Breeding and Agroindustrial Production. The reproductive capacity of the pigs was determined after receiving the farrowing by the following traits: piglets born alive per farrowing (animals), weight of litters of piglets at birth (kg), average weight of piglet at birth (kg), number of weaning piglets (animals), weight of litters of piglets at 28 days (kg), average weight of piglet at 28 days (kg), average daily gain of suckling piglets from 0 to 28 days (g). It was established that the traits of reproductive ability of crossbred Large White × Landrace pigs were affected by the interaction of genotype and feeding factors. When limiting the nutritional value of the daily diet, sows with the AG genotype outperformed those with the GG genotype by 1.2 piglets born alive per farrowing, by 3.0 kg for litter weight at birth, and by 0.1 kg for the average weight of a piglet at birth. The advantage of the AG genotype for average piglet weight at 28 days was even larger. Conversely, in conditions of a high level of feeding, animals with the GG genotype had higher productivity in terms of such traits as piglets born alive per farrowing – by 1.6 animals; weight of litters of piglets at birth – by 4.1 kg; for average weight of piglet at birth – 0.2 kg; by number of weaning piglets – 2.0 animals; by weight of litters of piglets at 28 days – 28.8 kg; for average weight of piglet at 28 days – 1.1 kg and for average daily gain from 0 to 28 days – 34.6 g. In the future, the goal is to develop a system of differentiated rationing of pigs' diets depending on their genotype.