The effects of feeding finishing pigs of two genders with a high fiber and high fat diet on muscle glycolytic potential at slaughter and meat quality

Dietary glycine supplementation enhances creatine availability in tissues of pigs with intrauterine growth restriction

This study tested the hypothesis that dietary supplementation with glycine (Gly) enhances the synthesis and availability of creatine (Cr) in tissues of pigs with intrauterine growth restriction (IUGR). At weaning (21 d of age), IUGR pigs and litter mates with normal birth weights (NBW) were assigned randomly to 1 of the 2 groups, namely, supplementation with 1% Gly or 1.19% l-alanine (isonitrogenous control) to a corn- and soybean meal-based diet. Blood, kidneys, liver, pancreas, jejunum, longissimus lumborum muscle (LLM), and gastrocnemius muscle (GM) were obtained from the pigs within 1 wk after the feeding trial ended at 188 d of age to determine concentrations of guanidinoacetate (GAA), Cr, creatinine, and phosphocreatine (CrP). The organs were also analyzed for activities and mRNA levels for Cr-synthetic enzymes: l-arginine:glycine amidinotransferase (AGAT; forming GAA from Gly and l-arginine) and guanidinoacetate n-methyltransferase (GAMT; converting GAA and l-methionine into Cr). AGAT activity was present in the kidneys, liver, and pancreas, whereas GAMT activity was found in all the organs analyzed. AGAT and GAMT were most active per gram of tissue in the kidneys and pancreas, respectively. Based on tissue mass, the kidneys had the greatest (P < 0.001) AGAT activity per whole organ, followed by the liver, while skeletal muscle had the greatest (P < 0.001) GAMT activity per whole organ, followed by the liver. Thus, the kidneys played a dominant role in forming GAA, whereas skeletal muscle and liver were the major sites for converting GAA into Cr. Dietary supplementation with 1% Gly enhanced AGAT activity in the kidneys and pancreas but reduced GAMT activity in the pancreas and small intestine, therefore directing GAA to the liver and skeletal muscle for Cr production. IUGR selectively reduced the concentration of Cr in LLM among all the organs studied. Except for the GM that had greater mRNA levels for GAMT in IUGR than in NBW pigs, neither Gly nor IUGR affected mRNA levels for the selected genes in the tissues examined. Collectively, these novel results indicate that dietary Gly intake upregulates the Cr-synthetic pathway in swine.

Muscle characteristics comparison and targeted metabolome analysis reveal differences in carcass traits and meat quality of three pig breeds

This study investigated the molecular basis for differences in meat yield and quality between Duroc, Taoyuan black (TB), and Xiangcun black (XB) pigs. The results show that TB pigs have lower carcass weight, lean percentage, pH decline, and glycolytic potential but have higher fat percentage, water- holding capacity, intramuscular fat content, antioxidant capacity, and percentage of slow-twitch fibers than the Duroc pigs. Moreover, muscles of TB pigs have lower protein synthesis and lipolysis gene expression than the muscles of Duroc pigs. Targeted metabolome analysis indicates that 24 metabolites significantly differ among these three pig breeds. Correlation analysis suggests that L-malic acid and β-alanine contents in muscle are closely related to meat quality. These findings suggest that the excellent meat quality of TB pigs is closely related to muscle metabolism and fiber characteristics, while lower protein synthesis and lipolysis may contribute to less meat yield.

Genetic architecture for skeletal muscle glycolytic potential in Chinese Erhualian pigs revealed by a genome-wide association study using 1.4M SNP array

Introduction: Muscle glycolytic potential (GP) is a key factor affecting multiple meat quality traits. It is calculated based on the contents of residual glycogen and glucose (RG), glucose-6-phosphate (G6P), and lactate (LAT) contents in muscle. However, the genetic mechanism of glycolytic metabolism in skeletal muscle of pigs remains poorly understood. With a history of more than 400 years and some unique characteristics, the Erhualian pig is called the “giant panda” (very precious) in the world’s pig species by Chinese animal husbandry.

Methods: Here, we performed a genome-wide association study (GWAS) using 1.4M single nucleotide polymorphisms (SNPs) chips for longissimus RG, G6P, LAT, and GP levels in 301 purebred Erhualian pigs.

Results: We found that the average GP value of Erhualian was unusually low (68.09 μmol/g), but the variation was large (10.4–112.7 μmol/g). The SNP-based heritability estimates for the four traits ranged from 0.16–0.32. In total, our GWAS revealed 31 quantitative trait loci (QTLs), including eight for RG, nine for G6P, nine for LAT, five for GP. Of these loci, eight were genome-wide significant (p &lt; 3.8 × 10−7), and six loci were common to two or three traits. Multiple promising candidate genes such as FTO, MINPP1, RIPOR2, SCL8A3, LIFR and SRGAP1 were identified. The genotype combinations of the five GP-associated SNPs also showed significant effect on other meat quality traits.

Discussion: These results not only provide insights into the genetic architecture of GP related traits in Erhualian, but also are useful for pig breeding programs involving this breed.

An alternative asymmetric figure-of-eight single-layer suture technique for bowel anastomosis in an in vitro porcine model

Anastomotic techniques are of vital importance in restoring gastrointestinal continuity after resection. An alternative asymmetric figure-of-eight single-layer suture anastomotic technique was introduced and its effects were evaluated in an in vitro porcine model. Twelve 15-cm grossly healthy small intestine segments from a porcine cadaver were harvested and randomly divided into asymmetric figure-of-eight single-layer suture (figure-of-eight suture) and single-layer interrupted suture technique (interrupted suture) groups (n = 6 in each group). The anastomosed bowel was infused with methylene blue solution to test anastomotic leakage. Anastomosis construction time, leakage, and suture material cost were recorded and analyzed statistically using Fisher's exact test and Student's t-test. One anastomotic leakage occurred (16.67%) in the figure-of-eight suture group, and two (33.33%) in the interrupted suture group (p &gt; 0.9999). The anastomosis construction time was relatively short in the figure-of-eight suture group, but the difference did not reach a statistically significant level between the two groups. The mean number of suture knots and the cost of suture material in the figure-of-eight suture group were significantly decreased in comparison to the interrupted suture group (15.67 ± 3.30 vs. 22.17 ± 2.03, 167.11 ± 35.20 vs. 236.45 ± 21.70 CNY, p &lt; 0.01, respectively). Our results suggested that the alternative asymmetric figure-of-eight suture technique was safe and economic for intestinal anastomosis. An in vivo experiment is required to elucidate the effects of this suture technique on the physiological anastomotic healing process.