The effect of a dietary linseed (Linum usitatissimum L.) supplement on the traits of fattening, carcass value, physical and chemical characteristics of meat quality, and the fatty acid composition of pig meat was evaluated. Seventy-two hybrids (Czech Large White _(paternal) × (Czech Large White _(maternal) × Czech Landrace)) were divided into four treatments according to diet (0 and 150 g/kg linseed) and sex (barrows and gilts). A significantly (P = 0.050) higher feed conversion value was ascertained in barrows fed with linseed compared with the other three groups. Most of the physical and chemical characteristics of the carcasses were not significantly influenced by dietary linseed addition or sex. The linseed supplement significantly (P < 0.001) increased the polyunsaturated fatty acid (PUFA) content and PUFA/SFA (saturated fatty acid) ratio, especially through increasing the n-3 PUFA content, and decreased the monounsaturated fatty acid (MUFA) content, the MUFA/PUFA, MUFA/SFA, and n-6/n-3 PUFA ratios and the thrombogenic index. Supplementation of the diet with linseed modified the fatty acid composition and improved fatty acid ratios in both sexes, without any negative effect on performance, carcass value or physical and chemical indicators of pig meat quality.

BackgroundIndependent studies have shown that several single nucleotide polymorphisms (SNP) in the human FTO (fat mass and obesity associated) gene are associated with obesity. SNP have also been identified in the pig FTO gene, among which some are associated with selected fat-deposition traits in F2 crosses and commercial populations. In this study, using both commercial pig populations and an experimental Meishan × Pietrain F2 population, we have investigated the association between one FTO SNP and several growth and carcass traits. Association analyses were performed with the FTO polymorphism either alone or in combination with polymorphisms in flanking loci.MethodsSNP (FM244720:g.400C>G) in exon 3 of porcine FTO was genotyped by PCR-RFLP and tested for associations with some growth, carcass and fat-related traits. Proportions of genetic variance of four pig chromosome 6 genes (FTO, RYR1, LIPE and TGFB1) on selected traits were evaluated using single- and multi-locus models.ResultsLinkage analysis placed FTO on the p arm of pig chromosome 6, approximately 22 cM from RYR1. In the commercial populations, allele C of the FTO SNP was significantly associated with back fat depth and allele G with muscling traits. In the Meishan × Pietrain F2 pigs, heterozygotes with allele C from the Pietrain sows and allele G from the Meishan boar were more significantly associated with fat-related traits compared to homozygotes with allele G from the Pietrain and allele G from the Meishan breed. In single- and multi-locus models, genes RYR1, TGFB1 and FTO showed high associations. The contribution in genetic variance from the polymorphism in the FTO gene was highest for back fat depth, meat area on the musculus longissimus lumborum et thoracis tissues and metabolite glucose-6-phosphate dehydrogenase.ConclusionsOur results show that in pig, FTO influences back fat depth in the commercial populations, while in the Meishan × Pietrain F2 pigs with a CG genotype, heterosis occurs for several fat-related traits.

Abstract:Okrouhlá M., Stupka R., Čítek J., Šprysl M., Trnka M., Kluzáková E. (2008): Effect of lean meat proportion on the chemical composition of pork. Czech J. Food Sci., 26: 464-469.The objective of this work was to verify the effect of the lean meat proportion on the chemical composition of the meaty parts (loin and ham) of pork. A total of 116 finishing hybrid pigs commonly used in the Czech Republic were fattened for this purpose. The pigs were divided according to the lean meat proportion criterion into 3 groups, i.e. more than 60.0%, 55.0-59.9% and 50.0-54.9%. Representative muscle samples were taken from the right halves of these pigs. They were then homogenised and submitted to chemical analysis. The results of the measuring showed that the values of the water content, intramuscular fat (IMF), crude proteins, and ash matter ranged in the loin between 72.50-72.80%, 1.56-1.96%, 23.20-23.40%, and 1.37-1.40%, respectively, and in the ham between of 70.43-71.59%, 3.52-4.26%, 21.67-21.95%, and 1.42-1.56%, respectively. The ascertained values of the water content and crude proteins with regard to the increasing lean meat proportion in the carcasses did not show any developmental tendencies. As for the content of IMF, it was determined that the higher was the lean meat proportion, the lower was the IMF content. Concerned of sensoric quality traits it means that pork meat from supermeaty hybrid pigs shows lower quality. Concerning the content of ash matter, it was observed that the ash content increased with an increasing lean meat proportion. In the carcass part of the musculus longissimus lumborum et thoracis (MLLT), it was demonstrated that the higher was the lean meat proportion, the lower was the content of amino acids -threonine, isoleucine, lysine, aspartic acid, serine, and proline. From point of the production of exceedingly meaty pigs (over 60%), it can be expected a worse nutritional pork meat value. In the carcass portion of the musculus semimembranosus (MS), the contents of valine, isoleucine, phenylalanine, lysine, serine, proline, and glycine increased with an increasing lean meat proportion. Within the framework of statistical evaluation of differences between the groups, the values of IMF (p ≤ 0.01) in MLLT, water content, IMF, ash matter, threonine, valine, phenylalanine, lysine, aspartic acid, serine, glycine, and alanine in MS were highly significant (p ≤ 0.05; p ≤ 0.01 and p ≤ 0.001).Keywords: pig; meat; lean meat; chemical composition Meat quality has assumed great significance in recent years mainly due to the importance of quantitative and qualitative carcass value relationships. As pigs were becoming progressively leaner, more complaints were received from the food industry claming that the quality of meat had declined (Wood 2001). The importance of the pig in the meat industry according to the lean meat propor-

The influence of linseed and corn dietary supplements on the fatty acid (FA) composition of pork was evaluated. The effects of their appropriate use and dosage on pork meat and fat technological quality were also investigated. In total 72 pigs fed complete feed mixtures were divided into 4 groups: control (C), corn-(CD), linseed-(LD), and corn + linseed-supplemented (CLD). After slaughter the lean meat share, intramuscular fat content, meat and fat colour, shear force, drip loss, and malondialdehyde content were determined. Subsequently, the FA content and sum of saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) fatty acids, the n-6/n-3 fatty acid ratio, and atherogenic and thrombogenic indexes in the loin and backfat tissue were determined. Corn and lineseed supplementation increases the content of myristic, linoleic, α-linolenic, and eicosapentaenoic acids and reduces the amount of palmitic, palmitoleic, oleic, eicosenoic, and arachidonic acids. Therefore it reduces the PUFA/SFA ratio and improves atherogenic and thrombogenic indexes. No negative effects of linseed and corn supplementation on the technological characteristics of pork meat and backfat were registered. Due to the positive effects on indicators related to human health, linseed and maize supplementation can be recommended in pig diet.

Abstract:The current knowledge of factors regulating voluntary feed intake in pigs is quite limited. The objective of this study was to test the influence of the missense mutation p.Asp298Asn (AF087937:c.746G>A) of the MC4R gene on selected production traits in pig crosses. These crosses are commonly used on commercial farms in the Czech Republic. The allele frequencies of c.746G>A were as follows: G allele -0.59 and A allele -0.41. We detected statistically significant differences in the content of intramuscular fat in the musculus longissimus lumborum et thoracis, and a similar trend was observed in shoulder and neck. A allele correlated with higher values of fatness and G allele with a higher percentage of lean meat. However, we did not find any significant influence on either feed intake or growth rate in this study. For another mutation, p.Arg236His (NM_214173.1:c.707G>A), frequencies of alleles were disproportional (A allele -0.02 and G allele -0.98), only two genotypes were observed (AG and GG) and linkage disequilibrium was not detected. Therefore, we assume that the effect of this polymorphism on growth rate and fatness in the Czech population of pigs is negligible.