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As an important factor secreted by skeletal muscle, myonectin can regulate lipid metabolism and energy metabolism, but its role in the utilization of peripheral free fatty acids (FFAs) by porcine intramuscular fat cells remains to be further investigated. In this study, porcine intramuscular adipocytes were treated with recombinant myonectin and palmitic acid (PA), either alone or in combination, and then were examined for their uptake of exogenous FFAs, intracellular lipid synthesis and catabolism, and mitochondrial oxidation of fatty acids. The results showed that myonectin decreased the area of lipid droplets in intramuscular adipocytes (p < 0.05) and significantly increased (p < 0.05) the expression levels of hormone-sensitive lipase (HSL) and lipoprotein lipase (LPL). Moreover, myonectin can up-regulate the expression of p38 mitogen-activated protein kinase (p38 MAPK). Myonectin significantly promoted the uptake of peripheral FFAs (p < 0.01), improved (p < 0.05) the expression of fatty transport protein 1 (FATP1) and fatty acid binding protein 4 (FABP4) in intramuscular adipocytes. Myonectin also significantly increased (p < 0.05) the expression levels of fatty acid oxidation markers: transcription factor (TFAM), uncoupling protein-2 (UCP2) and oxidative respiratory chain marker protein complex I (NADH-CoQ) in mitochondria of intramuscular adipocytes. In summary, myonectin promoted the absorption, transport, and oxidative metabolism of exogenous FFAs in mitochondria, thereby inhibiting lipid deposition in porcine intramuscular adipocytes. [ABSTRACT FROM AUTHOR]

This study aimed to explore the protective effects of L-theanine supplementation on the diquat-challenged weaned piglets. A total of 160 weaned piglets were randomly divided into 4 groups using a 2 × 2 two-factor design, there were 4 replicates per group and 10 pigs per replicate. Piglets were fed diets (with 1000 mg/kg L-theanine addition or not), then challenged with diquat or saline on day 7. 21 days after challenge, two pigs from each replicate were selected for sample collection. Results showed that supplement with 1000 mg/kg L-theanine down-regulated the diarrhea rate, serum D-lactate level, tumor necrosis factor-α, and phosphorylation of extracellular regulated protein kinases (ERK1/2), p38 mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase (JNK) signaling in pigs without diquat challenge (p < 0.05). While for diquat-challenged piglets, L-theanine addition increased average daily gain, jejunum villus height, and interferon-γ level (p < 0.05). Meanwhile, L-theanine addition decreased the diarrhea rates and mortality, serum D-lactate level, and phosphorylation of ERK and JNK in diquat-challenged pigs (p < 0.05). These results demonstrate that L-theanine pretreatment could alleviate diquat-induced oxidative stress and improve intestinal barrier function in diquat-challenged weaned piglets, which can be attributed to suppression of MAPK phosphorylation signaling pathways. [ABSTRACT FROM AUTHOR]

This study was to investigate time-course effects of different types of dietary fiber on the energy values, fecal microbiota and short-chain fatty acid (SCFA) concentration in growing pigs. A total of 24 barrows (initial body weight, 19.8 ± 0.5 kg) were assigned to 4 dietary treatments based on body weight (BW) in a completely randomized design, including a basal diet (CON) and 3 fiber-rich diets replacing corn, soybean meal and soybean oil in the CON diet with 20% sugar beet pulp (SBP), defatted rice bran (DFRB) or soybean hull (SBH), respectively. Fresh feces were sampled on d 7, 14 and 21, followed by 5 d total feces and urine collections. The results showed that there were no differences in DE and ME between any of the fiber ingredients on d 7, 14 or 21. However, fiber inclusion decreased the DE and ME of the diet ( P  < 0.05) regardless of the time effect. Principal coordinate analysis (PCoA) revealed distinctly different microbial communities on the DFRB diet and SBH diet across different times ( P  < 0.05) and the fecal microbiota of the 4 diet groups demonstrated notably distinct clusters at each time point ( P  < 0.05). With adaptation time increased from 7 to 21 d, cellulose-degrading bacteria and SCFA-producing bacteria (e.g., Ruminococcaceae &#95;UCG-014 , Rikenellaceae &#95;RC9&#95;gut&#95;group and Bifidobacterium ) increased in the fiber inclusion diets, and pathogenic genera (e.g., Streptococcus and Selenomonas ) were increased in the basal diet ( P  < 0.05). Furthermore, the gut microbiota of growing pigs adapted more easily and quickly to the SBP diet compared to the DFRB diet, as reflected by the concentration of propionate, butyrate, isovalerate and total SCFA which increased with time for growing pigs fed the DFRB diet ( P  < 0.05). Collectively, our results indicated at least 7 d adaptation was required to evaluate the energy values of fiber-rich ingredients, as the hindgut microbiota of growing pigs may need more time to adapt to a high fiber diet, especially for insoluble dietary fiber., Competing Interests: No conflict of interest exists in the submission, and all authors have approved the manuscript., (© 2022 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.)