DGAT1, AGL and protoncogen c-myc genes have been mapped on chromosome 4 and considered as candidate genes for carcass quality traits. The aim of the study was to characterize the polymorphism of these genes in four groups of pigs and to evaluated the relationship between the DGAT1, AGL and c-myc genotype and carcass traits. The animals of cross-breed PLW x PL were used only to characterize these polymorphisms. All animals studied appeared to be polymorphic at these loci. Statistical analysis was carried out for each breed separately using the least square methods of the GLM procedure. The relationship between the polymorphism and several productive traits was identified in each of the study group of pigs. Animals carrying heterozygous genotype at this locus showed most extreme values for some of the traits tested. Our results suggest that these genotypes might be utilized in the selection of valuable pig carcass traits.

The intergenic SNP (single-nucleotide polymorphism) rs80860411A>C was identified as a major QTL for drip loss measured on semimembranosus muscle (SM) in pigs. The SNP is located near the GALNT15. The purpose of this study was to analyze the association between rs80860411A>C and fattening, slaughter, and quality traits of Polish pigs. This study was conducted on 235 individuals belonging to two breeds, Polish Large White (n = 187) and Pulawska (n = 48). The rs80860411 genotypes were determined using the PCR-RFLP method. Association analysis was performed for each breed separately. It was shown that rs80860411A>C had a significant effect on fattening performance traits, on several slaughter performance traits, including width of the loin eye and carcass meat content (p ≤ 0.01, p ≤ 0.05), as well as on meat color—redness (a*) (p ≤ 0,05) in Pulawska breed. The obtained results indicate that the studied SNP has the potential to be a QTN and could be included in pig selection programs, especially in Pulawska pigs.

The aim of the study was to analyze the association between single nucleotide polymorphism (SNP) rs80860411A>C located in the intergenic region of chromosome 13 (near the GALNT15 gene encoding Polypeptide N-Acetylgalactosaminyltransferase15, GALNTL2) and fat-tening and slaughter traits of pigs. The study was conducted on 426 individuals belonging to three breeds: Polish Landrace (n = 192), Polish Large White (n = 187) and Pulawska (n = 48). The rs80860411 genotypes were determined using the PCR-RFLP method. Association analysis was performed for each breed separately, as well as for the entire study group. The study showed that rs80860411A>C had a significant effect on fattening performance traits, as well as on several slaughter performance traits, including: width of the loin eye, loin and ham weights without skin and backfat and carcass meat content (P ≤ 0.01, P ≤ 0.05). The obtained results indicate that the studied SNP has the potential to be included in pig selection programs, thus potentially influencing the improvement of fat-tening and slaughter traits of different pig breeds.

Genes encoding retinol binding protein 4 (RBP4), follicle stimulating hormone subunit beta (FSHB) and epidermal growth factor (EGF) have been proposed as candidate genes for reproduction traits in pigs. The study presented in this paper aimed to find associations between variants of these genes and reproduction traits in pigs reared in Poland. Investigation included Polish Large White x Polish Landrace (n=288) and Yorkshire (n=195) sows. Individual genotypes were determined by means of PCR-RFLP (single nucleotide polymorphism in RBP4, FSHB) or PCR (insertion/deletion in EGF) methods. Obtained result showed that RBP4 variants were related to total number born (TNB) and number born alive (NBA) in 1st, 2nd and 5th parities, FSHB to TNB and NBA in first two parities, however EGF with both traits in all parities (P≤0.05 or P≤0.01). In case of RBP4 gene, heterozygous genotype (AB) was favorable for analyzed traits, however in case of FSHB and EGF homozygous genotype, AA and BB respectively. Obtained results indicate that polymorphism in three analyzed genes is associated with important reproductive traits of pigs kept in Poland.

The genetic basis of aggressive behaviour has been examined extensively, including analysis of genes encoding neurotransmitters, signalling molecules and regulatory enzymes, as well as their synthesis and degradation. Dopamine beta-hydroxylase, an enzyme catalysing the conversion of dopamine into norepinephrine in synaptic endings, significantly affects the modulation of emotional states and behaviour. The aim of this study was to determine the association of C789A polymorphism in the canine dopamine beta-hydroxylase gene ( DBH ) and aggressive behaviour in dogs. A total of 110 dogs of different breeds were analysed. All animals were classified according to their individual behavioural characteristics, defined by a veterinary interview and observation. Polymorphism was analysed using ACRS-PCR (amplification created restriction site-polymerase chain reaction) method. Significant differences in DBH genotypes and allele frequency between aggressive and non-aggressive dogs were observed (χ 2 = 16,232, P = 0.0003). In aggressive dogs, the CC genotype (0.788) and C allele (0.815) were most frequent while in non-aggressive dogs, their frequencies were significantly lower (0.361 and 0.404, respectively). The obtained results indicate that DBH is a promising candidate gene for canine behavioural study.

Abstract The primary aim of this study was to estimate the relationship between ATP citrate lyase (ACLY) gene polymorphism (c.*523 T>C) and fattening and pork quality traits. Investigations were carried out on 526 pigs represented by three breeds: Polish Landrace (n=269), Polish Large White (n=189) and Puławska (n=68). ACLY genotypes were determined by PCR–RFLP method. It was demonstrated that the analyzed polymorphism had significant influence (P<0.05 and P≤0.01) on several economically important traits in pigs, e.g. average daily gain, average backfat thickness, lean meat percentage. The results obtained allow for application of c.*523 T>C polymorphism in breeding programs to improve the pig population in terms of fattening and slaughter traits. However, this breeding program may have a slight negative effect on meat texture parameters.

Thyroid hormone-inducible hepatic protein is involved in the de novo synthesis of fatty acids in the lactating mammary gland. Different variants of the gene that encodes this protein may be associated with its different activity. The primary aim of this study was to find polymorphism in the THRSP gene and estimate the relationship between individual genotypes and fatty acid composition in milk. Investigations were carried out on 224 cows represented by two breeds—Jersey (n = 80) and Polish Holstein-Friesian (n = 144). Polymorphism in THRSP was detected by Sanger sequencing; however, genotypes were determined by the PCR-RFLP method. It was shown that the analyzed variant had a significant (p < 0.05) influence on palmitic and stearic fatty acids as well as on fatty acids with a chain length of 14, 16, and 6–16 in Jersey breed and on caproic, palmitic, myristoleic, and palmitoleic fatty acids in H-F. Obtained results indicated that analyzed SNP in bovine THRSP gene (rs42714482) may be considered as a potential marker for fatty acid composition in milk

The aim of this study was to analyze the association of polymorphisms in alpha-ketoglutarate-dependent dioxygenase (FTO) and perilipin 2 (PLIN2) genes with carcass and meat quality traits in pigs reared in Poland. The research covered 578 sows that belong to the following breeds: Duroc, Hampshire, Polish Landrace, Pietrain, Pulawska and Polish Large White. PTO (FM244720:g.400C>G) and PLIN2 (GU1461317:g.98G>A) genes variants were determined by means of PCR-RFLP and ACRS-PCR methods respectively. Association between individual genotypes and analyzed traits was calculated by means of GLM procedure for Polish Landrace, Polish Large White and Pulawska breeds separately and for all six breeds together in case of FTO) gene. The results showed that FTO variants were associated with weight of loin without backfat and skin (WL), loin eye area (AL) and meat percentage (MP) in Polish Large White (P <= 0.05), mean backfat thickness from 5 measurements (BIT) and pH measured 45 min after slaughter in m longissimns dorsi (pH24 Id) as well as with water holding-capacity (WHC) in Pulawska breed (P <= 0.01). PLIN2 genotypes, however were correlated with WI, and height of the loin eye (IIL) in Polish Large White and Pulawska (P <= 0.05), AL in Polish Large White (P <= 0.01) as well as luminosity (L*) in Pulawska (P <= 0.05) pigs. We observed most consistent relationships of PLIN2 SNP with intramuscular fat content (IMF) and WHC. In 3 analyzed breeds GG genotype was connected with highest values of these traits (P <= 0.05).

FTO and PLIN2 genes are considered as a markers for fat-related traits in pigs.However, high expression of these genes in muscle tissues and earlier studies suggest, that they can be also associated with growth.Therefore the aim of this study was to analyze polymorphism in FTO (g.400C > G) and PLIN2 (g.98G > A) genes in relation to growth traits in pigs.The study were conducted on 578 sows including following breeds: Duroc, Hampshire, Polish Landrace, Pietrain, Puławska and Polish Large White.FTO and PLIN2 genes polymorphism was determined by use PCR-RFLP and ACRS-PCR methods respectively.Association analysis was performed for Polish Landrace, Puławska and Polish Large White separately and for joined group of 6 breeds.The results show that FTO genotypes were related only to test daily gain in Polish Large White pigs (p < 0.05).PLIN2 gene variants, however were associated with test daily gain in Polish Landrace, Puławska (p < 0.01) and joined group (p < 0.05), average daily gain in Puławska (p < 0.01), feed:gain ratio in joined group (p < 0.05) and age at slaughter and number of days on test in Puławska (p < 0.01) and joined group (p < 0.01 and p < 0.05 respectively).Obtained results show that PLIN2 gene is more related to growth traits in pigs than FTO, but needs further analysis and explanation.

The research was aimed at determining the physicochemical and sensory properties of the m. longissimus lumborum at DanAvl Hybrid (Landrace – Yorkshire) fatteners and derived from DanAvl Hybrid sows and DanAvl Duroc and Pulawska boars. Fatteners derived from DanAvl Duroc boars were characterized by better meat quality compared to DanAvl Hybrids and their hybrids with Pulawska breed as evidenced by higher pH in 24–96 h post mortem (p.m.), higher sensory evaluation of juiciness, tenderness and flavor as well as lower shear force at lower content of total protein and higher content of intramuscular fat (IMF). However, DanAvl Hybrid fatteners were characterized by poorer meat quality, i.e. higher color lightness (L*) and higher drip loss both from fresh and thawed meat compared to those derived from DanAvl Duroc and Pulawska boars. Meat of fatteners after Pulawska breed was characterized by the highest redness (a*), and that after DanAvl Duroc breed, the lowest yellowness (b*) and saturation (C*).

ABSTRACT Earlier studies have shown that insertion/deletion polymorphism (g.20311_20312ins291) in vertnin (VRTN) gene is associated with number of vertebrate in pigs. Because vertebral number determines the size of important meat cuts and influences carcass conformation, the aim of this study was to estimate the relationship between VRTN gene polymorphism and growth, slaughter and pork quality traits including texture parameters. Investigations were carried out on 526 pigs represented three breeds: Polish Landrace, Polish Large White and Puławska. VRTN gene polymorphism was determined by PCR methodology. Association study was performed for each breed separately. It was demonstrated that the analyzed polymorphism had significant influence on several economically important porcine traits. Among growth traits VRTN genotypes were associated with test and lifetime daily gains, number of days on test (p≤0.05) and age of slaughter (p≤0.01, p≤0.05). For carcass parameters, relationships were noticed for carcass yield (p≤0.01), weight of loin and its area, average backfat thickness and weight of primary cuts (p≤0.05). Taking into consideration meat quality, VRTN polymorphism influenced intramuscular fat content, meat colour (yellowness) and pH24 (p≤0.05). For texture parameters, it was correlated with toughness, cohesiveness, chewiness (p≤0.01, p≤0.05) and firmness (p≤0.05) measured in M. longissimus dorsi and M. semimembranosus. Only intramuscular fat content, chewiness of ham, carcass yield and cohesiveness of loin showed unequivocal tendency. In case of the first trait, each breed Wt/Wt genotype was associated with its highest values (p≤0.05), while the second and third traits, Q/Q genotype was correlated with its lowest values (p≤0.01, p≤0.05). Highest loin cohesiveness was observed in animals with Wt/Q genotype (p≤0.01, p≤0.05).

The research was aimed at determining the physicochemical and sensory properties of the m. longissimus lumborum at DanAvl Hybrid (Landrace – Yorkshire) fatteners and derived from DanAvl Hybrid sows and DanAvl Duroc and Pulawska boars. Fatteners derived from DanAvl Duroc boars were characterized by better meat quality compared to DanAvl Hybrids and their hybrids with Pulawska breed as evidenced by higher pH in 24–96 h post mortem (p.m.), higher sensory evaluation of juiciness, tenderness and flavor as well as lower shear force at lower content of total protein and higher content of intramuscular fat (IMF). However, DanAvl Hybrid fatteners were characterized by poorer meat quality, i.e. higher color lightness (L*) and higher drip loss both from fresh and thawed meat compared to those derived from DanAvl Duroc and Pulawska boars. Meat of fatteners after Pulawska breed was characterized by the highest redness (a*), and that after DanAvl Duroc breed, the lowest yellowness (b*) and saturation (C*).

Previous studies have shown that single nucleotide polymorphism (SNP) (rs328743478) located downstream of pre-miR-208b in MYH7 gene is correlated with fibre number composition and drip loss in pigs. Because fibre characteristics are linked to meat quality, the aim of this study was to analyse the relationships between rs328743478 polymorphism and meat quality and texture parameters. The study utilised 578 pigs belonging to Polish Landrace, Polish Large White, Puławska, Pietrain, Duroc, and Hampshire breeds. Association study was performed for the first three breeds separately and for all six breeds joined together. Obtained results showed a significant influence (P ≤ 0.05) of miR-208b genotypes on water holding capacity (WHC) in the whole population and individual breeds and on intramuscular fat content (IMF) and luminosity in the whole population as well as in Landrace and Puławska breeds, respectively. By analysing texture parameters, we found association (P ≤ 0.05 or P ≤ 0.01) between rs328743478 polymorphism and toughness, firmness, and chewiness measured in m. semimembranosus and m. longissimus lumborum. The highest values of these traits in m. semimembranosus were noticed for AA genotype, however in m. longissimus lumborum for GG in the whole population and some individual breeds. It was found that miR-208b genotypes were also associated with cohesiveness (P ≤ 0.01), springiness, and hardness (P ≤ 0.05) but obtained results were not consistent among breeds and the whole population. The obtained results confirm that miR-208b polymorphism is associated with some economically important traits in pigs.

The aim of this study was to evaluate MYH7 single nucleotide polymorphism (SNP) (NC_010449.4: g.7:75667956G>A) in relation to growth and carcass traits in pigs reared in Poland. Previous study has shown that g.7:75667956G>A substitution in pigs influences miR-208b and MYH7 expression, and is associated with proportion of muscle fibre types. The presented study was conducted on 582 pigs belonging to six breeds: Polish Landrace, Polish Large White, Pulawska, Pietrain, Duroc and Hampshire. Statistical analysis (GLM procedure) was performed for first three breeds separately and for whole group together. Our study showed that investigated SNP was associated with test daily gain, average daily gain, age at slaughter and number of days in experiment (P <= 0.05 or P <= 0.01) in Polish Large White, Pulawska and whole group. Among carcass traits MYH7 variants influenced mean backfat thickness from 5 measurements (P <= 0.05) in the same groups. We also noticed some associations for slaughter efficiency, weight of loin without backfat and skin, loin eye area and meat percentage (P <= 0.05 or P <= 0.01) but results were not consistent among breeds and whole group. Obtained results indicate that MYH7 SNP could be used as a genetic marker for improvement of some growth traits and backfat thickness in pigs.

The protein encoded by PPARCG1a gene is a key regulator of genes involved in energy metabolism. Numerous studies indicate that PPARGC1a gene may be a good marker for athletic performance in horses. Therefore the aim of this study was to detect polymorphisms in the promoter region of PPARGC1a gene and to evaluate its presence in horses belonging to nine different breeds (n = 268) as well as in elite and non-elite Thoroughbred racehorses with known racing outcomes (n = 276). By sequencing regulatory region of equine PPARGC1a gene one novel SNP (g. 100.784.525 C>G) was detected which changes transcription factors binding sites. To genotype polymorphism PCR-RFLP method was applied. Frequency of alleles and genotypes showed considerable differentiation in analyzed breeds. GG genotype was found only in Standardbred, Polish Heavy Draft horses and Purebred Arabian (0.04-0.13). The distribution of PPARGC1A genotypes was in Hardy-Weinberg equilibrium except Polish Heavy Draft horses (P= 0.05). Moreover disproportionate presence of the GC genotype in elite Thoroughbred racehorses over the CC genotype in the non-elite population (OR= 1.69) was noticed. Similarly GC genotype was overrepresented in distance runners in relation to sprinters analyzing all Thoroughbreds (OR= 2.00) as well as only elite horses (OR= 1.31). While there are multiple genes involved in athletic performance, given the association of PPARGC1A to mitochondrial biogenesis and conversion slow-twitch type I muscle fibers, this novel SNP may explain adaption in aerobic metabolism. The relationship between genotypes and gene expression should be performed next to evaluate its functional role.

The aim of the experiment was to detect polymorphism in GPX5 gene encoding glutathione peroxidase 5 and to determine associations between individual genotypes and following reproductive traits in the Polish Large White x Landrace crossbred sows (n=442): total number of piglets born (TNB), number of piglets born alive (NBA) and number of piglets weaned (NW). The polymorphism in GPX5 gene was detected using the PCR-RFLP method with specific primers and restriction enzyme HinfI. Two different alleles of the GPX5 gene were identified - 1B (0.42) and 2B (0.58). Genotype distribution was in a state of Hardy-Weinberg equilibrium. The association analysis showed significant (P <= 0.01) differences between sows carrying different genotypes and TNB, NBA, NW. The 1B1B genotype was favourable for all analyzed reproductive traits in first parity. In later parities similar tendency was observed, but differences were statistically not significant.

Association of CAST and RYR1 genes polymorphism with carcass and meat quality in crossbreed pigs with a share of Pietrain breed. The aim of this study is to determine the effect of the calpastatin (CAST/TaqI) and ryanodine receptor (RYR1) genes polymorphism on carcass and meat quality traits in Pietrain crossbred pigs. The polymorphism in CAST and RYR1 genes was detected using the PCR-RFLP (Restriction Fragment Length Polymorphism Analysis of PCR-Amplifi ed Fragments) method. Two alleles of CAST gene were identifi ed – A (0.34) and B (0.66) and three genotypes – AA (0.21), AB (0.25) and BB (0.54). In relation to carcass and pork quality, no statistically signifi cant differences were found between the CT and CC genotypes of RYR1 gene as well as between AA, AB and BB genotypes of CAST gene. In addition, no signifi cant interaction was found between CAST/TaqI × RYR1 genotypes and all the analyzed carcass and meat quality

The aim of this study was to estimate the relationship between prolactin receptor (PRLR) gene polymorphism and litter size in pigs of synthetic line 990 (n = 374). Prolactin receptor gene variants were determined by PCR-RFLP method. It was demonstrated that the analyzed polymorphism had significant influence (P <= 0.05) on reproduction traits in the first parity.

The aim of the study was to determine the effect of road transport, lairage time, meat % and carcass weight, sex, and PPARGC1A gene polymorphism on the degree of blood loss after slaughter. The study was conducted on 350 hybrid finishers from three farms located at different distance from the meat processing plant, but with the same methods of keeping animals and dietary treatment. The degree of blood loss was measured in the obliquus internus abdominis muscle using the compressor method. The results showed that the degree of blood loss from carcasses was influenced by the ambient temperature before slaughter, lairage time and the meat percentage in finishers. Finishers slaughtered without a pre-slaughter rest, with the shortest fasting time and the highest meat % of carcasses (>60%), were characterized by the lowest blood loss. In addition, blood loss was significantly related to ambient temperatures during the pre-slaughter handling, when pigs were transported for a distance of 232 km. Summarising, animal welfare proved to be significant for blood loss in pigs free of stress sensitivity gene (RYR1T), especially in those with high meat %. Appropriate transport conditions and a sufficiently long lairage time may help in obtaining higher post slaughter blood loss.