BackgroundIt is generally accepted that domestication of pigs took place in multiple locations across Eurasia; the breeds that originated in Europe and Asia have been well studied. However, the genetic structure of pig breeds from Russia, Belorussia, Kazakhstan and Ukraine, which represent large geographical areas and diverse climatic zones in Eurasia, remains largely unknown.ResultsThis study provides the first genomic survey of 170 pigs representing 13 breeds from Russia, Belorussia, Kazakhstan and Ukraine; 288 pigs from six Chinese and seven European breeds were also included for comparison. Our findings show that the 13 novel breeds tested derived mainly from European pigs through the complex admixture of Large White, Landrace, Duroc, Hampshire and other breeds, and that they display no geographic structure based on genetic distance. We also found a considerable Asian contribution to the miniature Siberian pigs (Minisib breed) from Russia. Apart from the Minisib, Urzhum, Ukrainian Spotted Steppe and Ukrainian White Steppe breeds, which may have undergone intensive inbreeding, the breeds included in this study showed relatively high genetic diversity and low levels of homozygosity compared to the Chinese indigenous pig breeds.ConclusionsThis study provides the first genomic overview of the population structure and genetic diversity of 13 representative pig breeds from Russia, Belorussia, Kazakhstan and Ukraine; this information will be useful for the preservation and management of these breeds.Electronic supplementary materialThe online version of this article (doi:10.1186/s12711-016-0196-y) contains supplementary material, which is available to authorized users.

Preserving the current diversity of the living material on Earth is fundamental for the survival of future generations . A study was conducted to investigate the genetic diversity of Ukrainian local pig breeds. A total of 350 pigs representing five local pig breeds from Ukraine (Mirgorod – MIR, Poltava Meat – PM, Ukrainian Meat – UM, Ukrainian White Steppe – UWS and Ukrainian Spotted Steppe – USS) and one commercial breed (Duroc, DUR) were sampled. Twelve microsatellite loci (SW24, S0155, SW72, SW951, S0386, S0355, SW240, SW857, S0101, SW936, SW911 and S0228) were selected and belong to the list of microsatellite markers recommended by ISAG. The results indicate that there exists, in general, a high degree of genetic variability within the five Ukrainian local pig breeds. However, the genetic variability in the MIR and PM breeds was significantly lower (mean Na = 2.92–3.92; Ho = 0.382–0.411; FIS = 0.178–0.184) than in the other three Ukrainian local pig breeds – UM, UWS and USS (mean Na = 5.00–8.42; Ho = 0.549–0.668; FIS = 0.027–0.066). Thirty-four private alleles were identified among the six analyzed genetic groups which were distributed between 11 of the 12 loci. A high number of alleles typical for the breed (private alleles) was observed in Duroc pigs – 9 alleles did not occur in Ukrainian local pig breeds. The HWE test showed that all of the polymorphic loci deviated from HWE (P < 0.05) in at least one population. Loci S0355 (5), S0386 (4) and SW24 (4) presented a higher number of populations in imbalance. The mean FST showed that approximately 77.8% of the genetic variation was within-population and 12.2% was across the populations. The five Ukrainian local breeds were classified into two major groups, according to the phylogenetic tree, which was based on standard genetic distance. Overall, we found that 92.6% of the individual pigs were correctly assigned (324 out of 350) to the respective breed of origin, which is likely a consequence of the well-defined breed structure. Probabilities from the allocation test of individuals for the six pig genetic groups were estimated with Structure Harvester. In cluster 1 the highest grouping probabilities were found for the MIR (0.917) and PM (0.750) breeds. Local breeds UM (0.824) and USS (0.772) were grouped in cluster 2. Cluster 3 was related to the local pig breed USW (0.873). Cluster 4 presented high allocation probabilities for the commercial pig breed Duroc (0.924). The obtained results are important for the future conservation of Ukrainian local pig breeds.

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Purebred Ukrainian Meat (UM) breed pigs, which came from Limited Liability Company “Tavriyskie Svin'I” herd located in Skadovsky district (Kherson region, Ukraine), were studied. The reproduction traits investigated were total number of piglets born (TNB), number of piglets born alive (NBA), frequency of stillborn piglets (FSB), number of weaned piglets (NW), total weaning weight of litter (TWWL) and average piglet weaning weight (APWW) for sows farrowing between 2006 and 2012. The analysis covered reproductive characteristics of 49 sows in the first nine parities (n = 457 litters). The sows originated from different the UM dam lines. Two month farrowing periods (January/February, March/April, May/June, July/August, September/October, and November/December) were constructed and used for reproduction traits. Data were analyzed by use of general linear model (GLM) procedure with the statistical package MINITAB v. 15. The estimates of reproduction traits for UM sows were 10.73 ± 0.43 ind. for TNB, 9.36 ± 0.39 ind. for NBA, 10.5 ± 2.2% for FSB, 9.07 ± 0.30 ind. for NW, 128.1 ± 5.7 kg for TWWL and 14.39 ± 0.49 kg for APWW. Litter size had a nonlinear effect on probability of stillbirth; piglets from small and large litters were more susceptible to die at farrowing with a minimum probability (near 5.0%) for intermediate litters of 8–10 piglets. Results here indicate that weak genetic variation exists in different the UM dam lines for the reproduction traits. Based on the obtained results it can be concluded that influence of parity on the observed traits of litter size was highly statistically significant (P < 0.05–0.001). The TNB, NBA and NW decreased in the first-second parities and thereafter increased with the number of parities, reaching a maximum in parities 5 and 6. FSB was lowest in parities 2, 3 and 5. Farrowing month significantly influenced some reproduction traits also. Sows farrowing in May/June had the highest NW, TWWL and APWW.

The aim of this study was to analyze the genetic variability and population structure of the Landrace population by using 12 microsatellite markers. A total of 90 pigs representing one commercial breed (Landrace) were sampled. Twelve microsatellite loci (SW24, S0155, SW72, SW951, S0386, S0355, SW240, SW857, S0101, SW936 SW911 and S0228) were selected and belong to the list of microsatellite markers recommended by FAO/ISAG. GenAIEx software was used to calculate the allele frequencies, effective number of alleles (Ae), observed (Ho) and expected (He) heterozygosity, within-population inbreeding estimate (Fis), Shannon’s information index (ISh). Overall allele frequency values ranged from 0.006 to 0.9333 (at allele SW951120). The number of observed alleles (Na) detected ranged from 5 (S0155 and SW911) to 13 (SW72), with an overall mean of 9.00 ± 0.80 and a total of 108 alleles were observed at these loci. However, the effective number of alleles (Ae) ranged from 1.57 (SW951) to 5.49 (SW240) with a mean of 3.29 ± 0.33. Shannon’s information index (ISh) which measures the level of diversity, was sufficiently high – from 0.79 (for SW951) to 2.01 (for SW240) – with a mean of 1.43 ± 0.09. The overall means for observed (Ho) and expected (He) heterozygosities were 0.578 ± 0.009 and 0.662 ± 0.004, respectively, which ranged from 0.307 (SW951) to 0.814 (SW857) and 0.361 (SW951) to 0.818 (SW240), respectively. Of the 12 microsatellites analyzed using Fisher’s exact test, 50% were in Hardy-Weinberg equilibrium, and 6 were out of equilibrium (P < 0.05). Three mutation models namely, infinite allele model (I.A.M.), two phase model (T.P.M.), stepwise mutation model (S.M.M.) were estimated using the BOTTLENECK software. The results are indicated that the Landrace pig population is non-bottlenecked and remained at mutation-drift equilibrium. The study stands first in genetic characterization of the Ukrainian Landrace pig population through microsatellite markers. The various parameters and values used to quantify genetic variability, such as the high mean (and effective) number of alleles and the expected and observed heterozygosities, indicated high genetic variability in the Ukrainian Landrace pigs. The population has not undergone any recent and/or sudden reduction in the effective population size and remained at mutation-drift equilibrium.

The data were from 149 pigs from seven pig genetic groups raised in «Tavriys'ki Svyni» Ltd (Kherson region, Ukraine). The following genetic groups were included in our analyses: LW × LW (n = 19), LW × LN (n = 43), LW × PT (n = 13), LN × LN (n = 15), UM × LN (n = 23), UM × PT (n = 17) and UM×UM (n = 16). The objective this work was evaluation of animal reproductive traits using multivariate analysis. Variables measured and derived included total no. piglets born (TNB), no. piglets born alive (NBA), freq. of stillborn piglets (FSB), total litter birth weight (TLBW), average piglet birth weight (APBW), pre-weaning mortality in piglets (PWM), no. weaned piglets (NW), total weaning weight of litter (TWWL) and average piglet weaning weight (APWW). After standardization, multivariate analyses (Cluster analysis and Principal Component Analysis) were carried out using STATISTICA (StatSoft Ltd.) to place pig interbreeding combinations in groups in accordance with their degree of similarity and verify discriminatory capacity of the original traits in the formation of these groups. The tree diagram showed clear distances between the pig genetic groups studied. In the tree diagram obtained from the analysis of the distances between interbreeding combinations, two distinct groups (clusters) were seen, one with UM × LN and UM × UM animals, and the other with the rest of the pig genetic groups in the study. The eigenvalues for the first two Principal Components (PC1 and PC2) together accounted for near 65% of the variance of the pig’s reproductive traits. The first principal component (PC1) explained 34.9% total variation. It was represented by significant positive loadings for TNB, NBA and TLBW. The second principal component (PC2) accounted for an additional 29.7% of the generalized variance and was represented by significant loadings for NW, TWWL and APWW. Thus, PC1 defined no. piglets and total litter birth weight, while PC2 represented no. weaned piglets and total weaning weight of litter. In conclusion, the multivariate methods (Cluster Analysis and PCA) has been proven to be a very effective method to obtain a synthetic judgment of reproductive traits in pig.

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The effects of breed, sire and environmental factors on the birth and weaning weight of lambs The aim of this study was to determine the effect of some important factors influencing on the birth and weaning weight variability in lambs. Data from 2603 ewes was included in the analysis, where 3961 lambs were obtained during the five years of the research. Data was tested using analysis of variance (ANOVA) with the GLM procedure of Minitab Release 13.1. Our results presented significant influence on the year of lambing, breed, ram genotype, age of a dam, type of a birth (litter size), sex of a lamb and on the birth weight and weaning weight of lambs. Keywords: birth and weaning weight of lambs; ram genotype; year of lambing; age of ewes; litter size (type of birth); sex of a lamb; the Ascanian fine-fleece breed.