Intra- and interbreed genetic heterogeneity and divergence in four commercial pig breeds based on microsatellite markers

Population Subdivision and Migration Assessment of Mangalica Pig Breeds Based on Pedigree Analysis

In conserving the genetic diversity of domestic animal breeds, strategies that emphasise between-breed diversity may not be optimal, as they neglect within-breed variation. The aim of the present study was to assess the extent of population subdivision in three Mangalica pig breeds and the contribution of migration to their substructure. Wright's FST coefficient was calculated based on genealogical data with breeding animals born between 1981 and 2023, with three colour variants (Blonde, Swallow-Belly and Red). These Wright's FST coefficients were analysed using multidimensional scaling to reveal the population substructure. The average FST coefficient was 0.04 for the Blonde breed and 0.047 for the Swallow-Belly and Red Mangalica breeds, while these parameters were lower in the active herds at 0.03 and 0.04, respectively. The migration of individuals between herds was 61.63% for the Blonde breed and 75.53% and 63.64% for the Swallow-Belly and Red Magalica breeds, respectively. No population substructure was observed in any of the Mangalica breeds, which can be explained by the extensive migration between herds.

Level of phenotypic manifestation of feeding and meat qualities of young pigs of different intrabreed differentiation according to some multi-component evaluation indexes

The paper deals with the results of the search for fattening and meat qualities of young pigs of Large White breeds of different interbreeding differentiation according to some integrated indicators, the level of correlations between traits, and the economic efficiency of research results is calculated. The experimental part of the work was performed in agricultural formations of the Dnipropetrovsk region and the laboratory of animal husbandry of the State Establishment Institution “Institute of Grain Crops of NAAS of Ukraine”. Evaluation of young pigs for fattening and meat qualities was carried out taking into account the following indicators: average daily gain of live weight during the period of control fattening, kg, age achievement of live weight 100 kg, days, the thickness of the lard at the level of 6–7 thoracic vertebrae, mm, the length of the chilled carcass, cm. A comprehensive evaluation of young pigs for fattening and meat qualities was performed according to the Tyler and Sazer-Fredin indices. Economic efficiency of research results and biometric processing of the obtained data were carried out according to generally accepted methods. It was found that young pigs of the Large White breed of the controlled population at the age of 100 kg exceeded the minimum requirements of the elite class by 6.13%, the thickness of the lard at the level of 6-7 thoracic vertebrae – 32.25 % and the length of the chilled carcass – 3.92 %. A significant difference between animals of different interbreeding differentiation according to the Tyler index (groups I and III) was set up by the average daily gain of live weight during the control period of fattening (91.7 g), age of 100 kg live weight (7.3 days), lard thickness at the level of 6–7 thoracic vertebrae (3.4 mm), length of the chilled carcass (1.7 cm), length of bacon half of chilled carcass (2.7 cm). Taking into account the interbreed differentiation according to the Sazer-Fredin index, it is found that young pigs of the II group prevailed over their peers of I in terms of average daily increase in live weight during the period of control fattening by 4.03 %, age of achievement of live weight of 100 kg – 3.67 % and length of the chilled carcass – 0.2 %. The pairwise correlation coefficient between fattening and meat qualities of young pigs and evaluation indices ranges from -0.710 (tr = 10.24) to +0.844 (tr = 20.98). The maximum increase in additional products was obtained from young pigs of the first experimental group according to the Tyler index (+5.03 %) and the second experimental group according to the Sazer-Fredin index (+1.12 %). The cost of additional products got from the young pigs of these groups, provided that the selling price per 1 kg of live weight of young pigs at the time of the search was 47.5 UAH is +247.51 and +55.42 UAH/head, respectively.

Genetic diversity of the Central European wild boar (Sus scrofa scrofa) population and domestic pig (Sus scrofa domesticus) breeds based on a microsatellite DNA locus

The results of studies of the genetic structure of the Central European wild boar (Sus scrofa scrofa) population and four breeds of domestic pigs (Duroc, Yorkshire, Large White and Landrace) bred in the Central Black Earth region of Russia are presented in this work. Based on 12 microsatellite loci, a significant ( p <0.05) decrease in the level of genetic variability in bred breeds was shown. The expected heterozygosity and Shannon index were as follows: in the wild boar, Ho = 0.763 ± 0.026, I = 1.717 ± 0.091; in the Duroc breed, Ho = 0.569 ± 0.068, I = 1.191 ± 0.157; in the Landrace, Ho = 0.618 ± 0.062, I = 1.201 ± 0.147; in the Large White, Ho = 0.680 ± 0.029, I = 1.362 ± 0.074; and in the Yorkshire, Ho = 0.642 ± 0.065, I = 1.287 ± 0.156. The results of checking genotypic Hardy–Weinberg equilibrium based on the G-test of maximum likelihood demonstrated that the overwhelming majority of loci in the wild boar population were in the state of said equilibrium. By contrast, in pig breed populations, some loci demonstrated a significant deviation from the indicated equilibrium. In addition, the Yorkshire, Large White, and Landrace populations had loci, for which the hypothesis of neutrality was reliably rejected based on the results of the Ewens–Watterson test. The revealed private alleles, characteristic of the wild boar and breeds, can later be used to identify them. The ordination of the centroids of different herds in the space of the first two principal coordinates based on the matrix of pairwise estimates of Nei’s genetic distances showed that the most distant populations are the Duroc and Boar breeds, and the most genetically close are the Yorkshire and Landrace breeds. The closest to the wild boar population was the Large White breed. The assessment of the effective size, carried out using the method based on the linkage disequilibrium and the molecular coancestry method, showed that in all studied groups, including the wild boar population, the effective size was less than 100 individuals. The low effective size of the wild boar population (Ne = 21.8, Neb = 4.0) is probably caused by the death and shooting of animals due to Pestis africana suum.