Supplementation of sows with L-Arginine during gestating and lactation affects muscle traits of offspring related with postnatal growth and meat quality: From conception to consumption

Maternal Hypermethylated Genes Contribute to Intrauterine Growth Retardation of Piglets in Rongchang Pigs

The placenta is a crucial determinant of fetal survival, growth, and development. Deficiency in placental development directly causes intrauterine growth retardation (IUGR). IUGR can lead to fetal growth restriction and an increase in the mortality rate. The genetic mechanisms underlying IUGR development, however, remain unclear. In the present study, we integrated whole-genome DNA methylation and transcriptomic analyses to determine distinct gene expression patterns in various placental tissues to identify pivotal genes that are implicated with IUGR development. By performing RNA-sequencing analysis, 1487 differentially expressed genes (DEGs), with 737 upregulated and 750 downregulated genes, were identified in IUGR pigs (H_IUGR) compared with that in normal birth weight pigs (N_IUGR) (p < 0.05); furthermore, 77 miRNAs, 1331 lncRNAs, and 61 circRNAs were differentially expressed. The protein-protein interaction network analysis revealed that among these DEGs, the genes GNGT1, ANXA1, and CDC20 related to cellular developmental processes and blood vessel development were the key genes associated with the development of IUGR. A total of 495,870 differentially methylated regions were identified between the N_IUGR and H_IUGR groups, which included 25,053 differentially methylated genes (DMEs); moreover, the overall methylation level was higher in the H_IUGR group than in the N_IUGR group. Combined analysis showed an inverse correlation between methylation levels and gene expression. A total of 1375 genes involved in developmental processes, tissue development, and immune system regulation exhibited methylation differences in gene expression levels in the promoter regions and gene ontology regions. Five genes, namely, ANXA1, ADM, NRP2, SHH, and SMAD1, with high methylation levels were identified as potential contributors to IUGR development. These findings provide valuable insights that DNA methylation plays a crucial role in the epigenetic regulation of gene expression and mammalian development and that DNA-hypermethylated genes contribute to IUGR development in Rongchang pigs.

Effect of dietary arginine supplementation on protein synthesis, meat quality and flavor in growing lambs

This study aimed to assess the effect of dietary arginine supplementation on protein synthesis, meat quality and flavor in lambs. Eighteen Dorper (♂) × Small Tailed Han sheep (♀) crossed ewe lambs of similar weight (27.29 ± 2.02 kg; aged 3 months) were assigned to two groups, the control group was fed the basal diet (Con group), and the arginine group (Arg group) was supplemented with 1% l-arginine based on the Con group for 90 d. The results suggested that dietary arginine significantly increased final body weight, loin eye muscle area, muscle fiber diameter, cross-sectional area (P < 0.050), and decreased shear force value and cooking loss (P < 0.050), as well as altered the composition and contents of volatile flavor compounds in lambs. Importantly, the total protein (TP) content, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP) activities in serum, branched-chain aminotransferase (BCAT), AST, ALT activities and neuronal nitric oxide synthase (nNOS) gene expression and content were elevated (P < 0.050), while content of urea nitrogen (BUN) in serum and 3-methylhistidine (3-MH) were decreased in arginine fed lambs (P < 0.050). In addition, arginine triggered muscle protein synthesis through protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway, while minimized protein degradation by regulating gene expression of myogenin (MyoG), myostatin (MSTN), muscle atrophy F-box (MAFbx) and forkhead box O3 family (FoxO3) (P < 0.050). Taken together, this study suggested that arginine can be used to improve protein deposition and meat quality in lamb production.

Probiotics and Synbiotics Addition to Bama Mini-Pigs' Diet Improve Carcass Traits and Meat Quality by Altering Plasma Metabolites and Related Gene Expression of Offspring

This study evaluated the effects of maternal probiotics and synbiotics addition on several traits and parameters in offspring. A total of 64 Bama mini pigs were randomly allocated into the control (basal diet), antibiotic (50 g/t virginiamycin), probiotics (200 mL/day probiotics), or synbiotics (500 g/t xylo-oligosaccharides and 200 mL/day probiotics) group and fed with experimental diets during pregnancy and lactation. After weaning, two piglets per litter and eight piglets per group were selected and fed with a basal diet. Eight pigs per group were selected for analysis at 65, 95, and 125 days of age. The results showed that the addition of probiotics increased the average daily feed intake of the pigs during the 66- to 95-day-old periods and backfat thickness at 65 and 125 days of age, and that the addition of synbiotics increased backfat thickness and decreased muscle percentage and loin-eye area at 125 days of age. The addition of maternal probiotics increased the cooking yield and pH45min value at 65 and 95 days of age, respectively, the addition of synbiotics increased the meat color at 95 days of age, and the addition of probiotics and synbiotics decreased drip loss and shear force in 65- and 125-day-old pigs, respectively. However, maternal antibiotic addition increased shear force in 125-day-old pigs. Dietary probiotics and synbiotics addition in sows' diets increased several amino acids (AAs), including total AAs, histidine, methionine, asparagine, arginine, and leucine, and decreased glycine, proline, isoleucine, α-aminoadipic acid, α-amino-n-butyric acid, β-alanine, and γ-amino-n-butyric acid in the plasma and longissimus thoracis (LT) muscle of offspring at different stages. In the LT muscle fatty acid (FA) analysis, saturated FA (including C16:0, C17:0, and C20:0) and C18:1n9t contents were lower, and C18:2n6c, C16:1, C20:1, and unsaturated FA contents were higher in the probiotics group. C10:0, C12:0, and C14:0 contents were higher in 65-day-old pigs, and C20:1 and C18:1n9t contents were lower in the synbiotics group in 95- and 125-day-old pigs, respectively. The plasma biochemical analysis revealed that the addition of maternal probiotics and synbiotics decreased plasma cholinesterase, urea nitrogen, and glucose levels in 95-day-old pigs, and that the addition of synbiotics increased plasma high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total cholesterol concentrations in 65-day-old pigs and triglyceride concentration in 125-day-old pigs. The addition of maternal probiotics and synbiotics regulated muscle fiber type, myogenic regulation, and lipid metabolism-related gene expression of LT muscle in offspring. In conclusion, the addition of maternal probiotics and synbiotics improved the piglet feed intake and altered the meat quality parameters, plasma metabolites, and gene expression related to meat quality.

Arginine promotes myogenic differentiation and myotube formation through the elevation of cytoplasmic calcium concentration

This study aimed to explore the mechanism underlying arginine-promoted myogenesis of myoblasts. C2C12 cells were cultured with a medium containing 0.1, 0.4, 0.8, or 1.2 mmol/L arginine, respectively. Cell proliferation, viability, differentiation indexes, cytoplasmic Ca²⁺ concentration, and relative mRNA expression levels of myogenic regulatory factors (MRF) and key Ca²⁺ channels were measured in the absence or presence of 2 chemical inhibitors, dantrolene (DAN, 10 μmol/L) and nisoldipine (NIS, 10 μmol/L), respectively. Results demonstrated that arginine promoted myogenic differentiation and myotube formation. Compared with the control (0.4 mmol/L arginine), 1.2 mmol/L arginine upregulated the relative mRNA expression levels of myogenin (MyoG) and Myomaker at d 2 during myogenic induction (P < 0.05). Cytoplasmic Ca²⁺ concentrations were significantly elevated by arginine supplementation at d 2 and 4 (P < 0.05). Relative mRNA expression levels of Ca²⁺ channels including the type 1 ryanodine receptor (RyR1) and voltage-gated Ca²⁺ channel (Cav1.1) were upregulated by 1.2 mmol/L arginine during 2-d myogenic induction (P < 0.01). However, arginine-promoted myogenic potential of myoblasts was remarkably compromised by DAN and NIS, respectively (P < 0.05). These findings evidenced that the supplementation of arginine promoted myogenic differentiation and myotube formation through increasing cytoplasmic Ca²⁺ concentration from both extracellular and sarcoplasmic reticulum Ca²⁺.

Impact of arginine supplementation on serum prolactin and mRNA abundance of amino acid transporter genes in mammary tissue of lactating sows

This study was conducted to test the hypothesis that supplemental dietary Arg to late-pregnant and lactating sows increases serum prolactin concentrations and mRNA abundance of SLC7A1, SLC7A2, and SLC6A14 in mammary parenchymal tissue. From day 108 of gestation and until day 21 of lactation, sows were fed a diet either supplemented with 0.10 g of l-Arg/kg body weight (BW) per day (n = 10, ARG) or 0.34 g of l-Glu/kg BW per day (n = 10, control). Litters were standardized to 10 piglets on day 1 of lactation and piglets were weighed on days 1, 7, 14, and 21 of lactation. Sow BW was recorded on day 108 of gestation and days 1, 10, and 21 of lactation. Lactation sow feed intake was recorded daily. Mammary parenchymal tissue was biopsied on day 5 of lactation to measure mRNA abundance SLC7A1, SLC7A2, and SLC6A14. On days 4 and 18 of lactation, blood samples were collected from sows at 2, 4, and 6 hr postfeeding to measure serum prolactin concentrations. Milk samples were collected on days 4, 10, and 18 of lactation to measure fat, lactose, urea N, and true protein concentrations. Sow BW, backfat, and feed intake over all sampling days did not differ between treatments. Piglet BW on d 1 tended to be greater for the ARG treatment than the control treatment (P = 0.12). Sow milk yield and composition (fat, protein, lactose, and urea N) and mammary mRNA abundance of candidate genes did not differ between the ARG and the control group. Compared to controls, serum prolactin concentrations tended to be greater (P = 0.08) in ARG sows on day 4 of lactation, and did not differ on day 18. Current findings show a potential beneficial effect of dietary supplementation with Arg to late-pregnant multiparous sows on BW of their piglets on day 1. Dietary Arg supplementation at a rate of 0.10 g/kg BW during late pregnancy and lactation tended to increase serum prolactin concentrations with no increase in mammary transcript abundance of SLC7A1, SLC7A2, and SLC6A14 in early lactation.

Differentially expressed marker genes and glycogen levels in pectoralis major of Ross308 broilers with wooden breast syndrome indicates stress, inflammation and hypoxic conditions

The occurrence of wooden breast (WB) in broiler production is increasing, but onset of its development is only described in part. In this study, we determined the regulation of marker genes related to oxidative stress in Ross308 broilers categorized as no-, mild- or severe-WB, on days 21 and 30 of production. The biochemical parameters, lactate dehydrogenase and pro- and macro-glycogen, were also determined. On day 21, breast meat from birds affected severely by WB had increased mRNA abundances of heat-shock protein 70, heme-oxygenase 1, cyclooxygenase 2, tumor necrosis factor 1, and hypoxia inducible factors as well as higher pH and lower dry matter contents. On day 30, breast meat from both mild and severely affected birds had increased mRNA for heme oxygenase 1, lactate dehydrogenase, and hypoxia inducible factor. Moreover, pro- and micro-glycogen, as well as the total pool of glycogen, were decreased compared with the non-WB birds. In conclusion, this study indicates oxidative stress, inflammation and hypoxic conditions in WB.

Resveratrol improves meat quality, muscular antioxidant capacity, lipid metabolism and fiber type composition of intrauterine growth retarded pigs

This study investigated whether resveratrol could improve meat quality, muscular antioxidant capacity, lipid metabolism and fiber type composition of intrauterine growth retarded pigs. Thirty-six pairs of male normal birth weight and intrauterine growth retardation (IUGR) piglets were orally fed with 80 mg resveratrol/kg body weight/d or vehicle during the sucking period (7-21 d). Then the offspring were fed with a basal diet containing 300 mg resveratrol/kg or a basal diet from weaning to slaughter (150 d). The IUGR-impaired meat quality (luminance and yellowness) was associated with muscular oxidative stress via increased Keap1 protein level, fat accumulation, and higher MyHC IIb gene expression. Expectedly, resveratrol increased glutathione peroxidase activity and MyHC I gene expression, reduced protein carbonyl and malondialdehyde contents, enhanced fatty acid oxidation via upregulated PPARα and targeted genes expression, and thereby improving drip loss and yellowness. Results indicate that resveratrol improved meat quality of IUGR pigs through enhancing antioxidant capacity, increasing oxidative fiber composition, and suppressing lipid accumulation.

Effects of dietary resveratrol supplementation in sows on antioxidative status, myofiber characteristic and meat quality of offspring

This study investigated the influence of dietary resveratrol (300 mg/kg) supplementation in sows on the antioxidative status, myofiber characteristic and meat quality of their progeny. Results showed that maternal dietary resveratrol supplementation increased (P < 0.05) the backfat thickness and tended (P = 0.055) to increase the intramuscular fat of finishing pigs. The drip loss and lactic acid level were reduced, and the pH_{24 h} of longissimus thoracis was increased by maternal dietary resveratrol supplementation (P < 0.05). Maternal dietary resveratrol supplementation increased the mRNA and protein expression of MyHC I and decreased the mRNA and protein expression of MyHC IIb in the longissimus thoracis (P < 0.05). The malonaldehyde (MDA) level in longissimus thoracis was reduced and the superoxide dismutase (SOD) activity and SOD2 mRNA expression were increased by maternal dietary resveratrol supplementation (P < 0.05). In conclusion, dietary resveratrol supplementation in sows improves the meat quality of offspring by altering the myofiber characteristic and antioxidative status.