Reproductive productivity depend on a complex set of characteristics. The number of piglets at birth (Total number born, Litter size, TNB) and the number of alive piglets at birth (Total number born alive, NBA) are the main indicators of the reproductive productivity of sows in pig breeding. Great hopes are pinned on GWAS (Genome-Wide Association Studies) to solve the problems associated with studying the genetic architecture of reproductive traits of pigs. This paper provides an overview of international studies on SNP (Single nucleotide polymorphism) associated with TNB and NBA in pigs presented in PigQTLdb as “Genome map association”. Currently on the base of Genome map association results 306 SNPs associated with TNB (218 SNPs) and NBA (88 SNPs) have been identified and presented in the Pig QTLdb database. The results are based on research of pigs such as Large White, Yorkshire, Landrace, Berkshire, Duroc and Erhualian. The presented review shows that most SNPs found in chromosome areas where candidate genes or QTLs (Quantitative trait locus) have been identified. Further research in the given direction will allow to obtain new data that will become an impulse for creating breakthrough breeding technologies and increase the production efficiency in pig farming.

Industrial pig farming is associated with negative technological pressure on the bodies of pigs. Leg weakness and lameness are the sources of significant economic loss in raising pigs. Therefore, it is important to identify the predictors of limb condition. This work presents assessments of the state of limbs using indicators of growth and meat characteristics of pigs based on machine learning algorithms. We have evaluated and compared the accuracy of prediction for nine ML classification algorithms (Random Forest, K-Nearest Neighbors, Artificial Neural Networks, C50Tree, Support Vector Machines, Naive Bayes, Generalized Linear Models, Boost, and Linear Discriminant Analysis) and have identified the Random Forest and K-Nearest Neighbors as the best-performing algorithms for predicting pig leg weakness using a small set of simple measurements that can be taken at an early stage of animal development. Measurements of Muscle Thickness, Back Fat amount, and Average Daily Gain were found to be significant predictors of the conformation of pig limbs. Our work demonstrates the utility and relative ease of using machine learning algorithms to assess the state of limbs in pigs based on growth rate and meat characteristics.

Тhe Melanocortin-4 Receptor (MC4R), a G-protein coupled receptor, is implicated in mediating the effect of leptin on food intake and energy balance. A previous candidate gene study reported an association between an MC4R polymorphism (Asp298Asn) and growth and meat productive traits of pigs. The aim of this work was to determine frequencies of the MC4R/Taq I genotypes and alleles in Danish Landrace (LD), Canadian Landrace (LC) and crossbred pigs Danish Landrace × Canadian Landrace (LD × LC) in breeding Cent "Plemzavod Jubilee" (Tyumen) Russia and to estimate their associations with some growth and meat traits. The polymorphism was identified by PCR-RFLP method. The traits studied were: Number of days to 100-kg, Average Daily Gain (ADG), Backfat Thickness (BFT), average daily Feed Intake (FI) and Length of Body (LB). In the all test groups we found a higher frequency of G allele (0.71) compared with the A allele (0.29). The results of present study suggest that the MC4R gene contributes to Days to 100 kg, ADG and BF. The heterozygous genotype AG was favorable in LD breed. The significant effects of-1.43 (LD male) and-2.81(LD female) for Days to 100 kg and of+61.17 (LD male) and +26.3 (LD female) for ADG were calculated. The homozygous genotype GG was favorable in crossbred LD × LC. The significant effects of +74.2 for ADG and-1.5 for BF were calculated. Therefore, the data support a role for the MC4R Asp298Asn polymorphism in the genetic basis of economically important traits in pigs of Russia. Further research is needed to determine the effect of this gene on growth, meat and reproduction traits in pigs of different breeds and crosses.

One of the areas of biotechnology sunflower is the development and testing of DNA markers of important agronomic traits and in particular markers of resistance to downy mildew. Resistance of 16 Rf-lines of sunflower to the races 330 and 710 of Plasmopara halstedii has been studied. Genotyping of these lines was carried out using 9 STS-markers of three Pl-loci, Pl 5 , Pl 6 and Pl 8 , associated with the resistance of sunflower to downy mildew. Only two out of nine STS-markers, НаР2 and НаР3 (locus Pl 6), allowed us to identify the lines, which demonstrated resistance to the downy mildew under the conditions of artificial infection.

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The Large White pig is the most commonly raised commercial pig breed in the world. The aim of this work was to investigate D-loop mtDNA in Large White pigs (n = 402) of various selections bred in the Russian Federation from 2000 to 2019. The general sample consisted of three groups: Old (n = 78) (Russian selection, 2000–2010); Imp (n = 123) (imported to Russia in 2008–2014); New (n = 201) (2015–2019). The synthesized score (Fz) was calculated by analyzing the main PCA (principal component analysis components). An affiliation to Asian or European haplogroups was determined according to the NCBI (National Center for Biotechnology Information). In the study, we defined 46 polymorphic sites and 42 haplotypes. Significant distinctions between groups Old, Imp and New in frequencies of haplotypes and haplogroups were established. The distribution of Asian and European haplotypes in the groups was Old: 50%/50%, Imp: 43%/57%, New: 75%/25%, respectively. The variety of haplotypes and haplogroups in the pigs of the group New is related to the farms in which they breed. Haplotype frequencies significantly differ between the clusters Old_Center, Old_Siberia and Old_South. This study will provide information on the genetic diversity of Large White breed pigs. The results will be useful for the conservation and sustainable use of these resources.

Intensive selection raises the efficiency of pig farming considerably, but it also promotes the accumulation of homozygosity, which can lead to an increase in inbreeding and the accumulation of deleterious variation. The analysis of segments homozygous-by-descent (HBD) and non-HBD segments in purebred and crossbred pigs is of great interest. Research was carried out on 657 pigs, of which there were Large White (LW, n = 280), Landrace (LR, n = 218) and F1 female (♂LR × ♀LW) (F1, n = 159). Genotyping was performed using the GeneSeek® GGP Porcine HD Genomic Profiler v1 (Illumina Inc., USA). To identify HBD segments and estimate autozygosity (inbreeding coefficient), we used the multiple HBD classes model. LW pigs exhibited 50,420 HBD segments, an average of 180 per animal; LR pigs exhibited 33,586 HBD segments, an average of 154 per animal; F1 pigs exhibited 21,068 HBD segments, an average of 132 per animal. The longest HBD segments in LW were presented in SSC1, SSC13 and SSC15; in LR, in SSC1; and in F1, in SSC15. In these segments, 3898 SNPs localized in 1252 genes were identified. These areas overlap with 441 QTLs (SSC1—238 QTLs; SSC13—101 QTLs; and SSC15—102 QTLs), including 174 QTLs for meat and carcass traits (84 QTLs—fatness), 127 QTLs for reproduction traits (100 QTLs—litter traits), 101 for production traits (69 QTLs—growth and 30 QTLs—feed intake), 21 QTLs for exterior traits (9 QTLs—conformation) and 18 QTLs for health traits (13 QTLs—blood parameters). Thirty SNPs were missense variants. Whilst estimating the potential for deleterious variation, six SNPs localized in the NEDD4, SEC11C, DCP1A, CCT8, PKP4 and TENM3 genes were identified, which may show deleterious variation. A high frequency of potential deleterious variation was noted for LR in DCP1A, and for LW in TENM3 and PKP4. In all cases, the genotype frequencies in F1 were intermediate between LR and LW. The findings presented in our work show the promise of genome scanning for HBD as a strategy for studying population history, identifying genomic regions and genes associated with important economic traits, as well as deleterious variation.

The most prospective and actual trend in farm animal breeding is studying gene polymorphisms affecting the productive traits. The objective of this investigation was to study the effect of polymorphisms in intron 1 of the swine POU1F1 gene on number of days to 100 kg (days to 100 kg), length of body (LB), backfat thickness (BF), and number of piglets born alive (NBA). Research was conducted on purebred pigs of Landrace (n = 80) and Duroc (n = 100) and crossbred pigs (Landrace × Large White) (n = 192). Insertions/deletions in intron 1 of the POU1F1 gene were defined by the PCR method. In Landrace the frequency of genotypes АА, АВ, and ВВ was 80.0%, 20.0%, and 0.0%; in crossbred pigs it was 63.0%, 29.0%, and 8.0%; and in Duroc it was 100.0%, 0.0%, and 0.0%, respectively. Significant effects of polymorphisms in intron 1 of the POU1F1 gene have been found in Landrace on days to 100 kg and LB and in crossbred pigs on LB and BF. The effect of the POU1F1 gene on NBA was not defined in our population. The obtained results show the possibility of using polymorphism in the 1st intron of the POU1F1 gene as a promising marker in breeding programs for improving growth and meat traits.