The objective of this study was to obtain heritability estimates for longevity (length of life, length of productive life, number of litters) and lifetime productivity traits (lifetime pig production, lifetime pig efficiency, lifetime litter efficiency) and genetic correlation between them and litter size at first farrowing, growth (ADG), backfat thickness (BF), loin depth, lean meat percentage (LMP), phenotypic selection index (PSI), and exterior in 19423 Polish Landrace (L) and 16049 Polish Large White (LW) sows. Heritabilities for longevity and lifetime productivity traits were 0.10-0.13 for L sows and 0.09-0.11 for LW sows depending on the trait definition. The genetic correlations among these traits were all high and positive, ranging from 0.76 to 0.99. Antagonistic genetic correlations (-0.21 to -0.26) were found between longevity traits and PSI and LMP in LW sows, while in L sows the respective parameters were lower and not significant for length of productive life. The number of live-born piglets in the first litter was positively correlated with lifetime pig production and lifetime pig efficiency in both breeds. The genetic correlations of longevity and lifetime pig production with ADG, BF, loin depth and exterior were small, and in most cases, not significant.

A total of 120 pigs from farm I and 109 from farm II were examined for DdeI polymorphism in myf3 and for MspI polymorphism in myogenin genes. Meatness, weight and ratio of ham and loin meat, and loin eye area of animals with different genotypes for myf3 and for myogenin were compared. In myf3 polymorphism pigs A/A from farm I displayed significantly lower values for these characteristics. In farm II there was a reverse tendency. Present results indicate that the DdeI polymorphic region in porcine myf3 gene does not influence functionality of this gene but it may point at another polymorphism located nearby and being of functional importance. Two regions of the porcine myogenin gene were analysed for MspI polymorphism. The region encompassing coding sequences (MYOG1) was polymorphic only in three Pietrain pigs (out of 150 individuals tested) making it useless for assessment of meat productivity in pigs. The 3′ untranslated region was polymorphic and the frequency of 4.2 and 4.9 alleles varied among breeds. The 4.2 variant was predominant in Pietrain pigs. Statistical analysis indicated that meat, ham and loin meat percentages as well as loin eye area were significantly higher in 4.2/4.2 homozygotes. Further study will be undertaken to explain the relations between meat productivity and myf3 and MYOG2 alleles within breed.

The optimal ratio of omega-6 to omega-3 polyunsaturated fatty acids (PUFAs) is important for keeping the homeostasis of biological processes and metabolism, yet the underlying biological mechanism is poorly understood. The objective of this study was to identify changes in the pig liver transcriptome induced by a diet enriched with omega-6 and omega-3 fatty acids and to characterize the biological mechanisms related to PUFA metabolism.Polish Landrace pigs (n = 12) were fed diet enriched with linoleic acid (LA, omega-6) and α-linolenic acid (ALA, omega-3) or standard diet as a control. The fatty acid profiling was assayed in order to verify how feeding influenced the fatty acid content in the liver, and subsequently next-generation sequencing (NGS) was used to identify differentially expressed genes (DEG) between transcriptomes between dietary groups. The biological mechanisms and pathway interaction networks were identified using DAVID and Cytoscape tools. Fatty acid profile analysis indicated a higher contribution of PUFAs in the liver for LA- and ALA-enriched diet group, particularly for the omega-3 fatty acid family, but not omega-6. Next-generation sequencing identified 3565 DEG, 1484 of which were induced and 2081 were suppressed by PUFA supplementation. A low ratio of omega-6/omega-3 fatty acids resulted in the modulation of fatty acid metabolism pathways and over-representation of genes involved in energy metabolism, signal transduction, and immune response pathways.In conclusion, a diet enriched with omega-6 and omega-3 fatty acids altered the transcriptomic profile of the pig liver and would influence animal health status.Electronic supplementary materialThe online version of this article (doi:10.1186/s12263-016-0517-4) contains supplementary material, which is available to authorized users.

the aim of the study was to examine the assimilability of organic and inorganic selenium supplied as an additive to pig feed. The influence of both selenium forms on pig slaughter value as well as on the physicochemical and sensory characteristics of meat was also examined (experiment i). an attempt to establish the distribution of selenium in the body of experimental fatteners was made (experiment ii). Experiment i was performed on 20 carcasses of crossbred pigs of (polish large White × polish landrace) × duroc genotype and experiment ii was carried out on 45 samples of longissimus and semimembranosus muscles taken from fatteners of the same genotype (plW × pl × duroc). the results obtained indicated that selenium supplementation in the diet had no impact on slaughter performance, meat quality and most physicochemical and sensory characteristics of meat. Selenium was found to have no significant effect on meat colour. The meat water holding capacity (Whc) was lower in the group of pigs fed organic selenium. the highest selenium concentration was found in the semimembranosus muscle of fatteners receiving the inorganic selenium additive.

BackgroundIdentification of selection signatures can provide a direct insight into the mechanism of artificial selection and allow further disclosure of the candidate genes related to the animals’ phenotypic variation. Domestication and subsequent long-time selection have resulted in extensive phenotypic changes in domestic pigs, involving a number of traits, like behavior, body composition, disease resistance, reproduction and coat color. In this study, based on genotypes obtained from PorcineSNP60 Illumina assay we attempt to detect both diversifying and within-breed selection signatures in 530 pigs belonging to four breeds: Polish Landrace, Puławska, Złotnicka White and Złotnicka Spotted, of which the last three are a subject of conservative breeding and substantially represent the native populations.ResultsA two largely complementary statistical methods were used for signatures detection, including: pairwise FST and relative extended haplotype homozygosity (REHH) test. Breed-specific diversifying selection signals included several genes involved in processes connected with fertility, growth and metabolism which are potentially responsible for different phenotypes of the studied breeds. The diversifying selection signals also comprised PPARD gene that was previously found to have a large effect on the shape of the external ear in pigs or two genes encoding neuropeptide Y receptors (Y2 and Y5) involved in fat deposition and stress response which are important features differentiating the studied breeds. REHH statistics allowed detecting several within-breed selection signatures overlapping with genes connected with a range of functions including, among others: metabolic pathways, immune system response or implantation and development of the embryo.ConclusionsThe study provides many potential candidate genes with implication for traits selected in the individual breeds and gives strong basis for further studies aiming at identification of sources of variation among the studied pig breeds.Electronic supplementary materialThe online version of this article (10.1186/s12863-018-0681-0) contains supplementary material, which is available to authorized users.