Pork Quality of Two Lithuanian Breeds: Effects of Breed, Gender and Feeding Regimen

The diversity of breeds is an important factor influencing carcass and meat quality traits that are also associated with other different effects. The objective of this study was to investigate the effects of breed, gender, and feeding level in the finishing phase on the carcass and meat quality of Lithuanian White and Lithuanian Indigenous Wattle pigs reared indoors. After 60 kg weight, half of the animals from both breeds were fed a restricted diet of approximately 82% of average ad libitum feeding intake, and the other half of pigs were further fed ad libitum to the end of the experiment. Feed restriction during the finishing phase decreased daily gain and weight of pigs at slaughter, and backfat thickness at the tenth rib (p ˂ 0.001, p ˂ 0.01, and p ˂ 0.05, respectively). Lithuanian White pigs demonstrated higher (p ˂ 0.001) growth rate, live body weight at slaughter and carcass weight, and had a higher (p ˂ 0.01) length of carcass and loin area and lower (p ˂ 0.05) backfat thickness at the last rib and at two points at the lumbar area compared with Lithuanian Indigenous Wattle pigs. The semimembranosus muscle of Lithuanian White pigs had relatively (8.1%) lower (p ˂ 0.001) proportions of saturated and 41.2% higher (p ˂ 0.001) proportions of polyunsaturated fatty acids compared with the pigs of the Lithuanian Indigenous Wattle breed, whereas in the longissimus muscle and subcutaneous tissue, the breed only affected the n-6/n-3 ratio (p ˂ 0.01 and p ˂ 0.001, respectively). Gender showed an effect on saturated fatty acids in all the studied tissues, however, the effects on polyunsaturated fatty acids were found in the semimembranosus muscle and subcutaneous tissue (p ˂ 0.05 and p ˂ 0.001) and the effects on monounsaturated fatty acids was found only in the semimembranosus muscle (p ˂ 0.01). These differences in the fatty acid composition of the semimembranosus muscle and subcutaneous tissue of females exhibited more favorable lipid quality indices compared with castrated males (p ˂ 0.001). The semimembranosus muscle of Lithuanian White pigs also showed more favorable lipid quality indices in relation to healthy nutrition compared with Lithuanian Indigenous Wattle pigs (p ˂ 0.001). This study is one of the steps toward the development and utilization of endangered breeds. The obtained information can be used to increase choice in pork production and consumption, and provides new insights for research into the conservation of local breeds.

Dissecting the Gene Expression Networks Associated with Variations in the Major Components of the Fatty Acid Semimembranosus Muscle Profile in Large White Heavy Pigs

To date, high-throughput technology such as RNA-sequencing has been successfully applied in livestock sciences to investigate molecular networks involved in complex traits, such as meat quality. Pork quality depends on several organoleptic, technological, and nutritional characteristics, and it is also influenced by the fatty acid (FA) composition of intramuscular fat (IMF). To explore the molecular networks associated with different IMF FA compositions, the Semimembranosus muscle (SM) from two groups of Italian Large White (ILW) heavy pigs divergent for SM IMF content was investigated using transcriptome analysis. After alignment and normalization, the obtained gene counts were used to perform the Weighted Correlation Network Analysis (WGCNA package in R environment). Palmitic and palmitoleic contents showed association with the same gene modules, comprising genes significantly enriched in autophagy, mitochondrial fusion, and mitochondrial activity. Among the key genes related to these FAs, we found TEAD4, a gene regulating mitochondrial activity that seems to be a promising candidate for further studies. On the other hand, the genes comprised in the modules associated with the IMF contents of oleic, n-6, and n-3 polyunsaturated FAs (PUFAs) were significantly enriched in Mitogen-Activated Protein Kinase (MAPK) signaling, in agreement with previous studies suggesting that several MAPK players may have a primary role in regulating lipid deposition. These results give an insight into the molecular cascade associated with different IMF FA composition in ILW heavy pigs. Further studies are needed to validate the results and confirm whether some of the identified key genes may be effective candidates for pork quality.

Feeding Tall Fescue Seed during Mid and Late Gestation Influences Subsequent Postnatal Growth, Puberty, and Carcass Quality of Offspring

Weaned lambs (n = 82), born to ewes fed endophyte-free (E−) or endophyte-infected (E+; 1.77 mg hd−1 d−1 ergovaline + ergovalinine) tall fescue seed from d 35 to 85 of gestation (MID) and/or d 86 of gestation to parturition (LATE), were used to examine how ergot alkaloid exposure during fetal development altered subsequent puberty attainment or carcass quality. Lambs were weaned at 75 d of age and separated by sex to assess puberty in ewe lambs (n = 39) and to evaluate growth, carcass and meat quality in wethers (n = 43). Data were analyzed with maternal fescue treatment, stage of gestation, and two-way interaction in the model. Age at puberty tended (P = 0.06) to be longer for ewe lambs born to dams fed E+ fescue during LATE gestation versus those fed E−. Post-weaning average daily gain tended to be higher (P = 0.07) for wether lambs born to dams fed E+ fescue seed during MID gestation compared to E−. Exposure to ergot alkaloids during fetal growth altered (P < 0.10) longissimus muscle weight and color, lipid deposition, fatty acid composition, and shear force values of semimembranosus muscle in wether lambs. These results indicate that exposure to ergot alkaloids in utero does alter subsequent post-weaning puberty attainment and body composition in offspring.

Effect of Breed on the Level of the Nutritional and Health-Promoting Quality of Semimembranosus Muscle in Purebred and Crossbred Bulls

Meat from commercial breed cattle are very often used to crossbreed with dairy breeds. The effect of heterosis is most evident when crossbreeds are genetically different from each other. Therefore, the aim of the study was to determine the influence of breed types on the nutritional and pro-health quality of beef. The experiment was conducted on 62 bulls from three breeds: Limousin, Polish Holstein-Friesian, and Polish Holstein-Friesian (PHF) × Limousin. During the fattening period, the animals were fed ad libitum using the same diet. Bulls were slaughtered at 21–23 months of age. The meat of PHF × Limousin hybrids was characterized by the lowest level of SFA and the highest content of n-3 PUFA fatty acids, carnosine, and α-tocopherol compared to the values obtained for the Polish Holstein-Friesian and Limousin breeds. In the case of PHF × Limousin hybrids, there was a 6% increase in n-3 PUFA, 21% in carnosine, and 66% in α-tocopherol compared to the Polish Holstein-Friesian breed. Commodity crossbreeding significantly improved the quality of beef analyzed in this study, resulting in similar or even better results than purebred cattle. This meant that beef from the hybrids with PHF was of the best nutritional and health-promoting quality.

Investigation of Various Intramuscular Volumes Delivered to the Semimembranosus Muscle of Cavia porcellus

The goal of this study is to provide quantitative data on the ideal volume for intramuscular (IM) injections into the semimembranosus muscle of guinea pigs weighing between 320 to 410 grams. This evaluation comprised 2 experiments. The first was to assess dispersion leakage of intramuscularly injected iohexol, a radiocontrast agent commonly used in Computed Tomography (CT), based on analysis of in vivo imaging. The second used varying volumes of intramuscularly injected sodium chloride (0.9% NaCl) to assess pain and pathology associated with IM injection. Hartley guinea pigs were injected IM with varying volumes of either iohexol or sodium chloride (150, 300, 500, 1000 and 1500 μL). In the iohexol experiment, results suggest IM volumes of 150 and 300 μL remain within the target muscle. In the experiment using sodium chloride, pain and pathology did not increase as IM volume increased. The pathology noted was related to needle tract through the musculature rather than the volume size of the injectate. The results did not reveal a correlation between volume of IM 0.9% NaCl and pain levels. We conclude that volume size correlates more with precision and accuracy of delivery into the intended muscle tissue. Regarding tissue distribution, our findings also suggest that the optimal capacity for IM injection in the semimembranosus muscle should be less than 500 μL.