Background Pork quality is affected by the type of muscle fibers, which is closely related to meat color, tenderness and juiciness. Exosomes are tiny vesicles with a diameter of approximately 30–150 nm that are secre...Background Pork quality is affected by the type of muscle fibers, which is closely related to meat color, tenderness and juiciness. Exosomes are tiny vesicles with a diameter of approximately 30–150 nm that are secreted by cells and taken up by recipient cells to mediate communication. Exosome-mediated muscle-fat tissue crosstalk is a newly discovered mechanism that may have an important effect on intramuscular fat deposition and with that on meat quality. Various of adipose tissue-derived exosomes have been discovered and identified, but the identification and function of muscle exosomes, especially porcine fast/slow myotube exosomes, remain unclear. Here, we first isolated and identified exosomes secreted from porcine extensor digitorum longus(EDL) and soleus(SOL), which represent fast and slow muscle, respectively, and further explored their effects on lipid accumulation in longissimus dorsi adipocytes.Results Porcine SOL-derived exosomes(SOL-EXO) and EDL-derived exosomes(EDL-EXO) were first identified and their average particle sizes were approximately 84 nm with double-membrane disc-shapes as observed via transmission electron microscopy and scanning electron microscopy. Moreover, the intramuscular fat content of the SOL was greater than that of the EDL at 180 days of age, because SOL intramuscular adipocytes had a stronger lipid-accumulating capacity than those of the EDL. Raman spectral analysis revealed that SOL-EXO protein content was much greater than that of EDL-EXO. Proteomic sequencing identified 72 proteins that were significantly differentially expressed between SOL-EXO and EDL-EXO, 31 of which were downregulated and 41 of which were upregulated in SOL-EXO.Conclusions Our findings suggest that muscle-fat tissue interactions occur partly via SOL-EXO promoting adipogenic activity of intramuscular adipocytes.展开更多
Background： The protein/energy ratio is important for the production performance and utilization of available feed resources by animals. Increased protein consumption by mammals leads to elevated feed costs and incre...Background： The protein/energy ratio is important for the production performance and utilization of available feed resources by animals. Increased protein consumption by mammals leads to elevated feed costs and increased nitrogen release into the environment. This study aimed to evaluate the effects of dietary protein/energy ratio on the growth performance, carcass traits, meat quality, and plasma metabolites of pigs of different genotypes. Methods： Bama mini-pigs and Landrace pigs were randomly assigned to two dietary treatment groups （Chinese conventional diet with low protein/energy ratio or National Research Council diet with high protein/energy ratio; n = 24 per treatment） in a 2 x 2 factorial arrangement. Blood and muscle samples were collected at the end of the nursery, growing, and finishing phases. Results： We observed significant interactions （P 〈 0.05） between breed and diet for total fat percentage, intramuscular fat （IMF） content, protein content in biceps femoris （BF） muscle, and plasma urea nitrogen （UN） concentration in the nursery phase; for average daily gain （ADG）, average daily feed intake （ADFI）, dry matter, IMF content in psoas major （PM） muscle, and plasma total protein and albumin concentrations in the growing phase; and for drip loss and plasma UN concentration in the finishing phase. Breed influenced （P 〈 0.05） growth performance, carcass traits, and meat quality, but not plasma metabolites. Throughout the trial, Landrace pigs showed significantly higher （P 〈 0.0_5） ADG, ADFI, dressing percentage, lean mass rate, and loin-eye area than did Bama mini-pigs, but significantly lower （P 〈 0.0.5） feed/gain ratio, fat percentage, backfat thickness, and IMF content. Dietary protein/energy ratio influenced the pH value, chemical composition of BF and PM muscles, and plasma activities of glutamic-pyruvic transaminase and gamma-glutamyl transpeptidase, and plasma concentration of UN. Conclusions： Compared with Landrace pigs, Bama mini-pigs showed slower growth and lower carcass performance, but had better meat quality. Moreover, unlike Landrace pigs, the dietary protein/energy ratio did not affect the growth performance of Bama mini-pigs. These results suggest that, in swine production, low dietary protein/energy ratio may be useful for reducing feed costs and minimizing the adverse effects of ammonia release into the environment.展开更多
Background： The intestinal epithelium is an important barrier that depends on a complex mixture of proteins and these proteins comprise different intercellular junctions. The purpose of this study was to investigate ...Background： The intestinal epithelium is an important barrier that depends on a complex mixture of proteins and these proteins comprise different intercellular junctions. The purpose of this study was to investigate the postnatal and developmental changes in morphology, intercellular junctions and voltage-gated potassium（Kv） channels in the intestine of piglets during the suckling and post-weaning periods.Results： Samples of the small intestine were obtained from 1-, 7-, 14-, and 21-d-old suckling piglets and piglets on d 1, 3, 5, and 7 after weaning at 14 d of age. The results showed that the percentage of proliferating cell nuclear antigen（PCNA）-positive cells and alkaline phosphatase（AKP） activity, as well as the abundances of E-cadherin,occludin, and Kv1.5 m RNA and claudin-1, claudin-3, and occludin protein in the jejunum were increased from d 1to d 21 during the suckling period（P 〈 0.05）. Weaning induced decreases in the percentage of PCNA-positive cells,AKP activity and the abundances of E-cadherin, occludin and zonula occludens（ZO）-1 m RNA or protein in the jejunum on d 1, 3 and 5 post-weaning（P 〈 0.05）. There were lower abundances of E-cadherin, occludin and ZO-1m RNA as well as claudin-1, claudin-3 and ZO-1 protein in the jejunum of weanling piglets than in 21-d-old suckling piglets（P 〈 0.05）. The abundances of E-cadherin, occludin, ZO-1 and integrin m RNA were positively related to the percentage of PCNA-positive cells.Conclusion： Weaning at 14 d of age induced damage to the intestinal morphology and barrier. While there was an adaptive restoration on d 7 post-weaning, the measured values did not return to the pre-weaning levels, which reflected the impairment of intercellular junctions and Kv channels.展开更多
Background: Oxidative stress is a key factor that influences piglets' health. Taurine plays an imperative role in keeping the biological system from damage. This study was conducted to investigate the protective e...Background: Oxidative stress is a key factor that influences piglets' health. Taurine plays an imperative role in keeping the biological system from damage. This study was conducted to investigate the protective effect of taurine against muscle injury due to the secondary effect of diquat toxicity.Results: Our study found that taurine effectively and dose-dependently alleviated the diquat toxicity induced rise of feed/gain, with a concurrent improvement of carcass lean percentage. The plasma content of taurine was considerably increased in a dose-dependent manner. Consequently, dietary taurine efficiently improved the activity of plasma antioxidant enzymes. Furthermore, taurine attenuated muscle damage by restoring mitochondrial micromorphology, suppressing protein degradation and reducing the percentage of apoptotic cells in the skeletal muscle. Taurine supplementation also suppressed the genes expression levels of the antioxidant-, mitochondrial biogenesis-, and muscle atrophy-related genes in the skeletal muscle of piglets with oxidative stress.Conclusions: These results showed that the dose of 0.60% taurine supplementation in the diet could attenuate skeletal muscle injury induced by diquat toxicity. It is suggested that taurine could be a potential nutritional intervention strategy to improve growth performance.展开更多
Background： To investigate the effects of dietary crude protein（CP） restriction on muscle fiber characteristics and key regulators related to protein deposition in skeletal muscle, a total of 18 growing-finishing p...Background： To investigate the effects of dietary crude protein（CP） restriction on muscle fiber characteristics and key regulators related to protein deposition in skeletal muscle, a total of 18 growing-finishing pigs（62.30 ± 0.88 kg）were allotted to 3 groups and fed with the recommended adequate protein（AP, 16 % CP） diet, moderately restricted protein（MP, 13 % CP） diet and low protein（LP, 10 % CP） diet, respectively. The skeletal muscle of different locations in pigs, including longissimus dorsi muscle（LDM）, psoas major muscle（PMM） and biceps femoris muscle（BFM） were collected and analyzed.Results： Results showed that growing-finishing pigs fed the MP or AP diet improved（P 〈 0.01） the average daily gain and feed： gain ratio compared with those fed the LP diet, and the MP diet tended to increase（P = 0.09） the weight of LDM. Moreover, the ATP content and energy charge value were varied among muscle samples from different locations of pigs fed the reduced protein diets. We also observed that pigs fed the MP diet up-regulated（P 〈 0.05） muscular m RNA expression of all the selected key genes, except that myosin heavy chain（My HC） IIb,My HC IIx, while m RNA expression of ubiquitin ligases genes was not affected by dietary CP level. Additionally, the activation of mammalian target of rapamycin complex 1（m TORC1） pathway was stimulated（P 〈 0.05） in skeletal muscle of the pigs fed the MP or AP diet compared with those fed the LP diet.Conclusion： The results suggest that the pigs fed the MP diet could catch up to the growth performance and the LDM weight of the pigs fed the AP diet, and the underlying mechanism may be partly due to the alteration in energy status, modulation of muscle fiber characteristics and m TORC1 activation as well as its downstream effectors in skeletal muscle of different locations in growing-finishing pigs.展开更多
This study was conducted to explore the regulatory mechanism of leucine(Leu)on lipid metabolism of finishing pigs.Twenty-four Duroc×Landrace×Large cross pigs with an average body weight of68.33±0.97 kg ...This study was conducted to explore the regulatory mechanism of leucine(Leu)on lipid metabolism of finishing pigs.Twenty-four Duroc×Landrace×Large cross pigs with an average body weight of68.33±0.97 kg were randomly allocated into 3 treatment groups with 8 replicates per group(1 pig per replicate).The dietary treatments were as follows:control group(CON),0.25%Leu group and 0.50%Leu group.The experimental period was 42 d.The results showed as follows.(1)Compared with the CON,0.25%and 0.50%Leu increased(P<0.01)the average daily gain(ADG),while the average backfat thickness(ABT)and the ratio of feed intake to body weight gain(F:G ratio)were decreased(P<0.05).(2)In the 0.25%Leu group,the relative mRNA expression levels of sterol regulatory element binding protein-1c(SREBP1c),recombinant fatty acid transport protein 1(FATP1),chemerin and peroxisome proliferatoractivated receptorγ(PPARγ)were decreased but the level of fatty acid binding protein 4(FABP4)and fatty acid translocase(FAT/CD36)were increased in backfat tissue.In the 0.25%Leu group,the protein levels of p-Rictor,p-Raptor,p-eIF4E-binding protein 1(p-4EBP1),p-silent mating type information regulator 2homolog 1(p-SIRT1)and acetylation ribosome s6 protein kinase 1(Ac—S6K1)were increased(P<0.05).(3)Compared to the CON,the diversity of gut microbiota in the 0.25%Leu group was increased.Principal component analysis showed that the relative abundance of Bacteroidetes,Lactobacillus and Desulfovibrio was higher in the 0.25%Leu group than the CON,but the relative abundance of Firmicutes,Treponema and Shigella was lower than in the CON(P<0.05).(4)Four different metabolites were screened out from the serum of finishing pigs including allolithocholic acid(alloLCA),isolithocholic acid(isoLCA),ursodeoxycholic acid(UDCA)and hyodeoxycholic acid(HDCA),which correlate to various degrees with the above microorganisms.In conclusion,Leu could promote adipose tissue lipolysis of finishing pigs through the mTOR-SIRT1 signaling pathway,and S6K1 is acetylated at the same time,and the interaction between gut microbiota and bile acid metabolism is also involved.展开更多
This study evaluated the potential of mulberry leaf powder as an unconventional feed material for fin-ishing pigs by assessing the growth performance,antioxidative properties,fatty acid profile,and lipid metabolism in...This study evaluated the potential of mulberry leaf powder as an unconventional feed material for fin-ishing pigs by assessing the growth performance,antioxidative properties,fatty acid profile,and lipid metabolism in 180 Xiangcun black pigs.Pigs with an initial body weight(BW)of 71.64±1.46 kg were randomly assigned to 5 treatment groups,including the control diet and 4 experimental diets.The corn,soybean meal,and wheat bran in the control diet were partly replaced by 3%,6%,9%,or 12%mulberry leaf powder in experimental diets.There were 6 replicates(pens)of 6 pigs per replicate in each treatment.Blood and muscle samples were collected after the 50-day feed experiment.Compared with the control group,the 3%,6%,and 9%mulberry diets had no adverse effect(P>0.05)on the growth performance of pigs.The serum glutathione peroxidase activity and glutathione concentration increased linearly(P<0.05)with the increase in dietary mulberry inclusion.There was no significant difference in the relative expression levels of antioxidant-related genes in muscle tissue between the control and mul-berry groups.Inclusion of dietary mulberry powder increased(P<0.05)the content of polyunsaturated fatty acids,especially in the longissimus dorsi(LD)muscle,up-regulated(P<0.05)the relative mRNA expression level of uncoupling protein-3 in muscle tissue,but down-regulated(P<0.05)the relative mRNA expression levels of hormone-sensitive lipase,acetyl CoA carboxylaseα,lipoprotein lipase,and peroxisome proliferator-activated receptor y in LD in a linear pattern.The nuclear respiratory factor 2 expression level in the LD muscle of pigs fed the 9%mulberry diet was higher(P<0.01)than that in the other mulberry groups and control group.The inclusion of less than 12%dietary mulberry did not detrimentally affect the growth performance of Xiangcun black pigs,but enhanced the serum antioxidant property,increased the polyunsaturated fatty acid content,and inhibited lipid oxidation by regulating gene expression levels of lipid metabolism and mitochondrial uncoupling protein in muscle tissue.Mulberry leaves can be utilized as a forage crop in the diet of finishing pigs.展开更多
Serine and glycine are 2 of the first-affected nonessential amino acids in low crude protein(CP)diets for pigs.Therefore,we explored the effects of different dietary serine-to-glycine ratios on growth perfor-mance and...Serine and glycine are 2 of the first-affected nonessential amino acids in low crude protein(CP)diets for pigs.Therefore,we explored the effects of different dietary serine-to-glycine ratios on growth perfor-mance and lipid metabolism in growing-finishing pigs.A total of 160 crossbred healthy barrows,with a similar body weight of around 59.50 kg,were randomly allotted into 1 of 5 treatments(8 pens per treatment and 4 pigs per pen).The serine-to-glycine ratios of the 5 dietary treatments were as follows:diet A(NORMAL group),1.18∶1(16%CP);diet B(LOW group),1.2∶1(12%CP);diet C(S2G1 group),2∶1(12%CP);diet D(S1G2 group),1∶2(12%CP);and diet E(S1G1 group),1∶1(12%CP).We found that the pigs fed a low CP diet(12%CP),when maintaining serine-to-glycine ratio at 1∶2 and a total amount of 1.44%,had the same average daily gain as the pigs fed a normal CP diet(16%CP)(P>0.05),but they had increased intramuscular fat(P<0.05).Furthermore,they exhibited higher expression of genes involved in lipid oxidation(P<0.05),which was regulated by modulating methylation levels in the promoters of acyl-CoA oxidase 1(ACOX1)and acyl-CoA dehydrogenase medium chain(ACADM).When compared with the pigs fed a normal CP diet,these pigs had more oxidative myofibers(P<0.05),which were regulated by AMPK-PGC-1αand Calcineurin-MEF2/NFAT pathways in a coordinated manner.Our findings suggested that a dietary serine-to-glycine ratio of 1:2 is beneficial for improving meat quality in pigs fed a low CP diet.展开更多
Pork meat is closely related to physicochemical alterations during growth and development,resulting in differences in nutritional value and meat flavor.This study aimed to evaluate the composition of amino acids,fatty...Pork meat is closely related to physicochemical alterations during growth and development,resulting in differences in nutritional value and meat flavor.This study aimed to evaluate the composition of amino acids,fatty acids,and metabolic profiles in the longissimus thoracis muscle(LM)of Shaziling pigs aged 30,90,150,210,and 300 days.The results showed that the predominant fatty acids identified in the LM of Shaziling pigs were C16:0,C16:1,C18:0,C18:1n9c,and C18:2n6c.An opposite correlation was observed for C18:2n6c and n6/n3 polyunsaturated fatty acids(P<0.05).Alanine,aspartate,glutamate,Dglutamine,and D-glutamate metabolism were the main metabolic pathways for the Shaziling pig meat flavor(P<0.05).Moreover,the correlation coefficients revealed that the contents of anserine,C16:0,C16:1,and C18:1n9c were positively correlated with intramuscular fat and/or p H24hand were negatively correlated with the values of L^(*)(lightness)and b^(*)(yellowness)(P<0.05).In conclusion,age greatly affected the meat quality of Shaziling pigs,and the contents of muscular anserine,C16:0,C16:1,and C18:1n9c might be promising indicators for better meat quality.展开更多
The objective of the study is to evaluate and compare the effects of betaine or glycine on carcass trait,meat quality and lipid metabolism of finishing Huan Jiang mini-pigs.Betaine called trimethylglycine is a methyl ...The objective of the study is to evaluate and compare the effects of betaine or glycine on carcass trait,meat quality and lipid metabolism of finishing Huan Jiang mini-pigs.Betaine called trimethylglycine is a methyl derivative of glycine,but few researches were conducted to compare the impact of dietary betaine and glycine on pigs.One hundred and forty-four Huan Jiang mini-pigs(body weight=10.55±0.15 kg;70 d)were randomly divided to 3 treatment groups(basal diet,glycine or betaine).Results indicated that dietary betaine increased the average daily gain(ADG)and final weight(P<0.05).Dietary glycine or betaine markedly reduced average backfat thickness(P<0.05)and heightened lean percentage(P<0.01)compared to the control group.Moreover,in comparison with the control group,betaine significantly improved the redness(a*)and tenderness(shear force)of the longissimus dorsi(LD)muscle(P<0.05),whereas glycine only raised the value of a*of the LD muscle(P<0.05).These results showed that diet supplemented with 0.25%betaine and equimolar amounts of glycine could regulate cascass trait and meat quality of finishing Huan Jiang mini-pigs,and the effect of betaine was superior to that of glycine.展开更多
This experiment was conducted to investigate the effects of branched-chain amino acids(BCAA)supplemented in protein-restricted diets on the growth performance and the expression profile of amino acid transporters and ...This experiment was conducted to investigate the effects of branched-chain amino acids(BCAA)supplemented in protein-restricted diets on the growth performance and the expression profile of amino acid transporters and energy metabolism related regulators in the white adipose tissue(WAT)of different regional depots including dorsal subcutaneous adipose(DSA) and abdominal subcutaneous adipose(ASA), A total of 24 crossbred barrows(7.40 ± 0.70 kg) were randomly divided into 4 groups and were fed the following isocaloric diets for 33 days: 1) a recommended adequate protein diet(AP, 20% CP, as a positive control); 2) a low protein diet(LP, 17% CP); 3) the LP diet supplemented with BCAA(LP + B, 17% CP) to reach the same level of the AP diet group; 4) the LP diet supplemented with 2 times the amount of BCAA(LP + 2B, 17% CP). The daily gain and daily feed intake of the LP diet group were the lowest among all the treatments(P < 0.01). The feed conversion was improved markedly in the group of LP + B compared with the LP diet group(P < 0.05). No significant difference was noted for the serum biochemical parameter concentrations of glucose, triglyceride, nonesterified fatty acid and insulin among the groups(P > 0.05). Moreover, BCAA supplementation down-regulated the expression levels of amino acid transporters including L-type amino acid transporter 1 and sodium-coupled neutral amino acid transporter 2 in DSA, but up-regulated the expression level of Ltype amino acid transporter 4 in ASA(P < 0.05), Meanwhile, the energy sensor AMP-activated protein kinase α was activated in the DSA of pigs fed LP diet and in the ASA of the pigs fed AP or LP + 2B diets(P < 0.05). The mRNA expression profile of the selected mitochondrial component and mitochondrial biogenesis associated regulators in DSA and ASA also responded differently to dietary BCAA supplementation. These results suggested that the growth performance of growing pigs fed protein restricted diets supplemented with BCAA could catch up to that of the pigs fed AP diets. The results also partly demonstrated that the regulation mechanisms of BCAA are different in the adipose tissues of different depots.展开更多
This study aims to compare the meat quality of Shaziling and Yorkshire pigs and to find the potential indicator in serum for superior meat quality.Six Shaziling and Yorkshire pigs at 30,60,90,150,210,and 300 d of age ...This study aims to compare the meat quality of Shaziling and Yorkshire pigs and to find the potential indicator in serum for superior meat quality.Six Shaziling and Yorkshire pigs at 30,60,90,150,210,and 300 d of age were selected to examine carcass traits,meat quality,and serum metabolome.The results showed that the body weight,carcass length,and loin eye area of Shaziling pigs at 150,210,and 300 d of age were significantly lower than those of Yorkshire pigs(P<0.05).Shaziling pigs at 150 and 300 d of age had significantly lower backfat thickness than Yorkshire pigs(P<0.05).Compared with Yorkshire pigs,Shaziling pigs at all 6 ages had a lower lean percentage and a higher fat percentage(P<0.05).At 60,90,and 150 d of age,the post-mortem pH-decline,b*value(yellowness),and drip loss of Shaziling pigs were significantly lower than those of Yorkshire pigs(P<0.05).Moreover,at 150 d of age,Shaziling pigs had significantly higher a^(*)value(redness)and intramuscular fat(IMF)content than Yorkshire pigs(P<0.05).Correlation analysis between the top 40 metabolites and phenotypes indicated that L-carnitine had positive correlations with fat percentage,pH24h,and IMF content,but had negative correlations with lean percentage,L^(*)value(lightness),and b^(*)value(P<0.05).Serum L-carnitine content,fat percentage,pH24h,and IMF content all decreased first and then increased as the pigs grew,which verified the positive correlations between L-carnitine and these phenotypes.In conclusion,Shaziling pigs have a slower growth rate but a better meat quality than Yorkshire pigs.The meat quality of Shaziling pigs is the best from 150 to 210 d of age.This study suggests that a higher serum L-carnitine content is a promising indicator for better meat quality.展开更多
Engineered probiotics can serve as therapeutics based on their ability of produce recombinant immune-stimulating properties.In this study,we built the recombinant Bacillus subtilis WB800 expressing antimicrobial pepti...Engineered probiotics can serve as therapeutics based on their ability of produce recombinant immune-stimulating properties.In this study,we built the recombinant Bacillus subtilis WB800 expressing antimicrobial peptide KR32(WB800-KR32)using genetic engineering methods and investigated its protective effects of nuclear factor-E2-related factor 2(Nrf2)-Kelch-like ECH-associated protein 1(Keap1)pathway activation in intestinal oxidative disturbance induced by enterotoxigenic Escherichia coli(ETEC)K88 in weaned piglets.Twenty-eight weaned piglets were randomly distributed into four treatment groups with seven replicates fed with a basal diet.The feed of the control group(CON)was infused with normal sterilized saline;meanwhile,the ETEC,ETEC+WB800,and ETEC+WB800-KR32 groups were orally administered normal sterilized saline,5×10^(10)CFU(CFU:colony forming units)WB800,and 5×10^(10)CFU WB800-KR32,respectively,on Days 1-14 and all infused with ETEC K881×10^(10)CFU on Days 15-17.The results showed that pretreatment with WB800-KR32 attenuated ETEC-induced intestinal disturbance,improved the mucosal activity of antioxidant enzyme(catalase(CAT),superoxide dismutase(SOD),and glutathione peroxidase(GPx))and decreased the content of malondialdehyde(MDA).More importantly,WB800-KR32 downregulated genes involved in antioxidant defense(GPx and SOD1).Interestingly,WB800-KR32 upregulated the protein expression of Nrf2 and downregulated the protein expression of Keap1 in the ileum.WB800-KR32 markedly changed the richness estimators(Ace and Chao)of gut microbiota and increased the abundance of Eubacterium_rectale_ATCC_33656 in the feces.The results suggested that WB800-KR32 may alleviate ETEC-induced intestinal oxidative injury through the Nrf2-Keap1 pathway,providing a new perspective for WB800-KR32 as potential therapeutics to regulate intestinal oxidative disturbance in ETEC K88 infection.展开更多
To study the effects of dietary energy level on the meat quality of different muscles in finishing pigs,400Xiangcun Black pigs(BW=79.55±4.77 kg)were randomly assigned to 5 treatments with varied calculated digest...To study the effects of dietary energy level on the meat quality of different muscles in finishing pigs,400Xiangcun Black pigs(BW=79.55±4.77 kg)were randomly assigned to 5 treatments with varied calculated digestive energy(DE)at 3,050,3,100,3,150,3,200 and 3,250 kcal/kg,respectively.Each treatment had 8replicates with 10 pigs per replicate.Meat quality,amino acid and fatty acid composition were tested in this study.No differences in average daily gain,average daily feed intake or feed-to-gain ratio(P>0.05)were observed among dietary treatments.Glycogen concentrations of longissimus dorsi(LD)muscle in DE3150was higher than those in other groups(P<0.05).The crude fat concentration of biceps femoris(BF)muscle in DE3250 tended to be higher than that in DE3150 and DE3100 groups(P<0.05).Pigs in DE3250 and DE3200 had higher fiber density and smaller cross-sectional area of BF muscle than those in DE3150(P<0.05).Pigs in DE3150 had the highest Cu concentration in LD muscle compared with those in DE3200,DE3250(P<0.05).The C16:1 proportion of LD muscle was lower(P<0.01)and C20:1 was higher(P<0.05)in DE3050 than that in the other dietary treatments.The C18:3n6 and C20:3n6 proportions of BF muscle in DE3150 were higher than those in DE 3050,DE3200 and DE3250(P<0.05).For LD muscle,m RNA expressions of type I and IIa MyHC in group DE3150 were higher than other treatments(P<0.01).The LD muscle in DE3150 expressed higher PPARd than in other groups(P<0.01).Pigs in DE3100 expressed higher FOX1 than in DE3200 and DE3250(P<0.05).Sterol-regulatory element binding proteins(SREBPa)mRNA expression decreased linearly when dietary energy level increased in BF muscle(P<0.01).In conclusion,a200 kcal/kg decrease in digestible energy for 4 consecutive weeks did not affect growth performance of Xiangcun Black pigs.Furthermore,LD and BF muscle respond differently to dietary energy level,and meat quality was improved by the medium energy level during the finishing phase.展开更多
Sodium-coupled neutral amino acid transporter 2(SNAT2),also known as solute carrier family 38 member 2(SLC38 A2),is expressed in the skeletal muscle.Our research previously indicated that SNAT2 m RNA expression level ...Sodium-coupled neutral amino acid transporter 2(SNAT2),also known as solute carrier family 38 member 2(SLC38 A2),is expressed in the skeletal muscle.Our research previously indicated that SNAT2 m RNA expression level in the skeletal muscle was modulated by genotype and dietary protein.The aim of this study was to investigate the key role of the amino acid transporter SNAT2 in muscle cell growth,differentiation,and related signaling pathways via SNAT2 suppression using the inhibitor a-methylaminoisobutyric acid(Me AIB).The results showed that SNAT2 suppression down-regulated both the m RNA and protein expression levels of SNAT2 in C2 C12 cells,inhibited cell viability and differentiation of the cell,and regulated the cell distribution in G0/G1 and S phases(P<0.05).Meanwhile,most of the intercellular amino acid content of the cells after Me AIB co-culturing was significantly lower(P<0.05).Furthermore,the m RNA expression levels of system L amino acid transporter 1(LAT1),silent information regulator 1,and peroxisome proliferator-activated receptor-gamma co-activator 1 alpha,as well as the protein expression levels of amino acid transporters LAT1 and vacuolar protein sorting 34,were all down-regulated.The phosphorylated protein expression levels of mammalian target of rapamycin(m TOR),regulatory-associated protein of m TOR,4 E binding protein 1,and ribosomal protein S6 kinase 1 after Me AIB treatment were also significantly down-regulated(P<0.05),which could contribute to the importance of SNAT2 in amino acid transportation and skeletal muscle cell sensing.In conclusion,SNAT2 suppression inhibited C2 C12 cell growth and differentiation,as well as the availability of free amino acids.Although the m TOR complex 1 signaling pathway was found to be involved,its response to different nutrients requires further study.展开更多
Interleukin-15(IL-15) is a cytokine highly expressed in skeletal muscle. The objective of the present study was to investigate the development of muscle IL-15 expression in suckling piglets and in early weaning piglet...Interleukin-15(IL-15) is a cytokine highly expressed in skeletal muscle. The objective of the present study was to investigate the development of muscle IL-15 expression in suckling piglets and in early weaning piglets(day 14) at each level, that is, mRNA, protein, and secretion. Eight litters(eight piglets per litter) of newborn healthy piglets(Large × White × Landrace) with a similar initial weight(1618.0 ± 140.1 g) were chosen and divided into two groups, Group one used suckling piglets that were killed, respectively, at days 1,7,14,21, and group two used early(day 14) weaning piglets that were killed respectively, at days 15, 17, 19, 21. In group one, IL-15 gene expression levels increased significantly(P < 0.05) along with increased body weight over time. IL-15 protein expression levels in piglets at day 21 of age were higher(P < 0.05) than those in piglets at other ages, and there was no difference(P > 0.05)among piglets at other ages. These findings indicated that increased IL-15 mRNA expression did not result in a corresponding increase of its protein expression. In group two, which used early weaning piglets from days 15-19, IL-15 mRNA and protein expression levels increased constantly(P < 0.05) and were higher(P < 0.05) than those in suckling piglets. Moreover, there was no gain of body weight(P > 0.05) compared with suckling piglets at day 14 of age. However, IL-15 protein expression levels in early weaning piglets at day 21 of age dropped significantly(P < 0.05) to the levels as suckling piglets at day 21 of age, while body weight increased(P < 0.05) markedly to the levels as suckling piglets at day 21 of age. In both groups, the serum IL-15 levels of piglets decreased significantly(P < 0.01) over time. Taken together, our results indicate that IL-15 expression differs in suckling piglets and in weaning piglets. It is speculated that IL-15 may play an important role in counteracting the effects of early weaning stress.展开更多
We previously demonstrated that lipopolysaccharide(LPS)injection-induced immune stress could impair muscle growth in weaned piglets,but the precise mechanisms behind this remain elusive.Here,we found that chronic immu...We previously demonstrated that lipopolysaccharide(LPS)injection-induced immune stress could impair muscle growth in weaned piglets,but the precise mechanisms behind this remain elusive.Here,we found that chronic immune stress induced by LPS resulted in a significant reduction of 36.86%in the total muscle mass of piglets at 5 d post-treatment compared with the control group.At 1 d,prior to muscle mass loss,multiple alterations were noted in response to LPS treatment.These included a reduction in the abundance of Bacteroidetes,an increase in serum concentrations of pro-inflammatory cytokines,compromised mitochondrial morphology,and an upregulation in the expression of dynamin-related protein 1(Drp1),a critical protein involved in mitochondrial fission.We highlight a strong negative correlation between Bacteroidetes abundance and the levels of serum pro-inflammatory cytokines,corroborated by in vivo intervention strategies in the musculature of both pig and mouse models.Mechanistically,the effects of Bacteroidetes on inflammation and muscle mass loss may involve the signaling pathway of the tauro-β-muricholic acid-fibroblast growth factor 15.Furthermore,the induction of overexpression of inflammatory cytokines,achieved without LPS treatment through oral administration of recombinant human IL-6(rh IL-6),led to increased levels of circulating cytokines,subsequently causing a decrease in muscle mass.Notably,pre-treatment with Mdivi-1,an inhibitor of Drp-1,markedly attenuated the LPS-induced elevation in reactive oxygen species levels and rescued the associated decline in muscle mass.Collectively,these data indicate that LPS-induced muscle mass loss was linked to the reduction of Bacteroidetes abundance,increased inflammation,and the disruption of mitochondrial morphology.These insights offer promising avenues for the identification of potential therapeutic targets aimed at mitigating muscle mass loss.展开更多
Tea trees have a long history of cultivation and utilization.People in many countries have the habit of drinking tea and choosing green tea,oolong tea,or black tea according to different regions and personal tastes.Te...Tea trees have a long history of cultivation and utilization.People in many countries have the habit of drinking tea and choosing green tea,oolong tea,or black tea according to different regions and personal tastes.Tea polyphe nols are a general term for polyphenol co mpounds in tea,and has been shown to have good effects on antioxidant,anti-inflammatory,cancer prevention and regulation of lipid metabolism.Tea polyphenols have been widely used as antioxidants in disease treatment and animal husbandry,but their specific mechanism of action needs to be further clarified and revealed.This review focuses on the definition,classification,antioxidant activity and the regulation of signaling pathways of tea polyphenols.This paper also aims to examine the application of tea polyphenols in human and animal health,providing a scientific basis for this application in addition to proposing future directions for the development of this resource.展开更多
Free radical-induced oxidative stress contributes to the development of metabolic syndromes(Mets), including overweight,hyperglycemia, insulin resistance and pro-inflammatory state. Most free radicals are generated fr...Free radical-induced oxidative stress contributes to the development of metabolic syndromes(Mets), including overweight,hyperglycemia, insulin resistance and pro-inflammatory state. Most free radicals are generated from the mitochondrial electron transport chain;under physiological conditions, their levels are maintained by efficient antioxidant systems. A variety of transcription factors have been identified and characterized that control gene expression in response to oxidative stress status.Natural antioxidant compounds have been largely studied for their strong antioxidant capacities. This review discusses the recent progress in oxidative stress and mitochondrial dysfunction in Mets and highlights the anti-Mets, anti-oxidative, and antiinflammatory effect of polyphenols as potential nutritional therapy.展开更多
A 60-days feeding trial was conducted to determine the effect of dietary supplementation of Lonicera macranthoides leaf(LML) on growth performance, meat quality, and free amino acid profiles in growingfinishing pigs. ...A 60-days feeding trial was conducted to determine the effect of dietary supplementation of Lonicera macranthoides leaf(LML) on growth performance, meat quality, and free amino acid profiles in growingfinishing pigs. L. macranthoides leaves were harvested, air-dried and milled to powder. A total of 288 crossbred barrows(Large White x Landrace) with an average initial BW of 54.0 ± 3.4 kg were randomly allocated to 3 treatment groups and fed either a basal diet or a diet supplemented with 0.5% or 1.0% LML powder. Results showed that diet supplemented with LML powder did not affect average daily feed intake(ADFI) and feed: gain ratio(P> 0.05) in growing-finishing pigs. Moreover, diet supplemented with LML powder showed no significant effects on carcass traits(P > 0.05) including dressing percentage,backfat thickness and loin muscle area, and meat quality traits(P > 0.05) including meat color, intramuscular fat and cooking loss. However, diet supplemented with LML powder significantly improved free amino acid profiles in serum and longissimus thoracis muscle in growing-finishing pigs. Most importantly, dietary LML powder increased total free amino acids content(P < 0.001) and essential free amino acid content(P < 0.001) in longissimus thoracis muscle. These results indicate that LML has the potential to improve the nutritional value of meat through improving free amino acid profiles.展开更多
基金supported by the National Natural Science Foundation of China (32272847, U22A20516)the Key Research and Development Program of Shaanxi Province (2022ZDLNY01-04)the China Agriculture Research System of MOF and MARA (CARS-35)。
文摘Background Pork quality is affected by the type of muscle fibers, which is closely related to meat color, tenderness and juiciness. Exosomes are tiny vesicles with a diameter of approximately 30–150 nm that are secreted by cells and taken up by recipient cells to mediate communication. Exosome-mediated muscle-fat tissue crosstalk is a newly discovered mechanism that may have an important effect on intramuscular fat deposition and with that on meat quality. Various of adipose tissue-derived exosomes have been discovered and identified, but the identification and function of muscle exosomes, especially porcine fast/slow myotube exosomes, remain unclear. Here, we first isolated and identified exosomes secreted from porcine extensor digitorum longus(EDL) and soleus(SOL), which represent fast and slow muscle, respectively, and further explored their effects on lipid accumulation in longissimus dorsi adipocytes.Results Porcine SOL-derived exosomes(SOL-EXO) and EDL-derived exosomes(EDL-EXO) were first identified and their average particle sizes were approximately 84 nm with double-membrane disc-shapes as observed via transmission electron microscopy and scanning electron microscopy. Moreover, the intramuscular fat content of the SOL was greater than that of the EDL at 180 days of age, because SOL intramuscular adipocytes had a stronger lipid-accumulating capacity than those of the EDL. Raman spectral analysis revealed that SOL-EXO protein content was much greater than that of EDL-EXO. Proteomic sequencing identified 72 proteins that were significantly differentially expressed between SOL-EXO and EDL-EXO, 31 of which were downregulated and 41 of which were upregulated in SOL-EXO.Conclusions Our findings suggest that muscle-fat tissue interactions occur partly via SOL-EXO promoting adipogenic activity of intramuscular adipocytes.
基金supported by the National Basic Research Program of China(No.2012CB124704 and 2013CB127305)KC.Wong Education Foundation,Hong Kong
文摘Background： The protein/energy ratio is important for the production performance and utilization of available feed resources by animals. Increased protein consumption by mammals leads to elevated feed costs and increased nitrogen release into the environment. This study aimed to evaluate the effects of dietary protein/energy ratio on the growth performance, carcass traits, meat quality, and plasma metabolites of pigs of different genotypes. Methods： Bama mini-pigs and Landrace pigs were randomly assigned to two dietary treatment groups （Chinese conventional diet with low protein/energy ratio or National Research Council diet with high protein/energy ratio; n = 24 per treatment） in a 2 x 2 factorial arrangement. Blood and muscle samples were collected at the end of the nursery, growing, and finishing phases. Results： We observed significant interactions （P 〈 0.05） between breed and diet for total fat percentage, intramuscular fat （IMF） content, protein content in biceps femoris （BF） muscle, and plasma urea nitrogen （UN） concentration in the nursery phase; for average daily gain （ADG）, average daily feed intake （ADFI）, dry matter, IMF content in psoas major （PM） muscle, and plasma total protein and albumin concentrations in the growing phase; and for drip loss and plasma UN concentration in the finishing phase. Breed influenced （P 〈 0.05） growth performance, carcass traits, and meat quality, but not plasma metabolites. Throughout the trial, Landrace pigs showed significantly higher （P 〈 0.0_5） ADG, ADFI, dressing percentage, lean mass rate, and loin-eye area than did Bama mini-pigs, but significantly lower （P 〈 0.0.5） feed/gain ratio, fat percentage, backfat thickness, and IMF content. Dietary protein/energy ratio influenced the pH value, chemical composition of BF and PM muscles, and plasma activities of glutamic-pyruvic transaminase and gamma-glutamyl transpeptidase, and plasma concentration of UN. Conclusions： Compared with Landrace pigs, Bama mini-pigs showed slower growth and lower carcass performance, but had better meat quality. Moreover, unlike Landrace pigs, the dietary protein/energy ratio did not affect the growth performance of Bama mini-pigs. These results suggest that, in swine production, low dietary protein/energy ratio may be useful for reducing feed costs and minimizing the adverse effects of ammonia release into the environment.
基金funded by the National Key Basic Research Program of China(2013CB127302)National Natural Science Foundation of China(31330075,31372326,31301988,31301989)+4 种基金the State Key Laboratory of Animal Nutrition(2004DA125184F1401)the Spark Program of Jiangxi Province(20142BBF061051)Changsha Lvye Biotechnology Limited Company Academician Expert WorkstationGuangdong Wangda Group Academician Workstation for Clean Feed Technology Research and Development in SwineGuangdong Hinapharm Group Academician Workstation for Biological Feed and Feed Additives and Animal Intestinal Health
文摘Background： The intestinal epithelium is an important barrier that depends on a complex mixture of proteins and these proteins comprise different intercellular junctions. The purpose of this study was to investigate the postnatal and developmental changes in morphology, intercellular junctions and voltage-gated potassium（Kv） channels in the intestine of piglets during the suckling and post-weaning periods.Results： Samples of the small intestine were obtained from 1-, 7-, 14-, and 21-d-old suckling piglets and piglets on d 1, 3, 5, and 7 after weaning at 14 d of age. The results showed that the percentage of proliferating cell nuclear antigen（PCNA）-positive cells and alkaline phosphatase（AKP） activity, as well as the abundances of E-cadherin,occludin, and Kv1.5 m RNA and claudin-1, claudin-3, and occludin protein in the jejunum were increased from d 1to d 21 during the suckling period（P 〈 0.05）. Weaning induced decreases in the percentage of PCNA-positive cells,AKP activity and the abundances of E-cadherin, occludin and zonula occludens（ZO）-1 m RNA or protein in the jejunum on d 1, 3 and 5 post-weaning（P 〈 0.05）. There were lower abundances of E-cadherin, occludin and ZO-1m RNA as well as claudin-1, claudin-3 and ZO-1 protein in the jejunum of weanling piglets than in 21-d-old suckling piglets（P 〈 0.05）. The abundances of E-cadherin, occludin, ZO-1 and integrin m RNA were positively related to the percentage of PCNA-positive cells.Conclusion： Weaning at 14 d of age induced damage to the intestinal morphology and barrier. While there was an adaptive restoration on d 7 post-weaning, the measured values did not return to the pre-weaning levels, which reflected the impairment of intercellular junctions and Kv channels.
基金supported by the National Key R&D Program(2018YFD0500405)the National Nature Science Foundation of China(31972582)+3 种基金the Science and technology projects of Changsha City(kq1801059)the STS regional key projects of Chinese Academy of Sciences(KFJ-STS-QYZD-052)the Youth Innovation Team Project of ISA,CAS(2017QNCXTD_ZCS)the Earmarked Fund for China Agriculture Research System (CARS-35)。
文摘Background: Oxidative stress is a key factor that influences piglets' health. Taurine plays an imperative role in keeping the biological system from damage. This study was conducted to investigate the protective effect of taurine against muscle injury due to the secondary effect of diquat toxicity.Results: Our study found that taurine effectively and dose-dependently alleviated the diquat toxicity induced rise of feed/gain, with a concurrent improvement of carcass lean percentage. The plasma content of taurine was considerably increased in a dose-dependent manner. Consequently, dietary taurine efficiently improved the activity of plasma antioxidant enzymes. Furthermore, taurine attenuated muscle damage by restoring mitochondrial micromorphology, suppressing protein degradation and reducing the percentage of apoptotic cells in the skeletal muscle. Taurine supplementation also suppressed the genes expression levels of the antioxidant-, mitochondrial biogenesis-, and muscle atrophy-related genes in the skeletal muscle of piglets with oxidative stress.Conclusions: These results showed that the dose of 0.60% taurine supplementation in the diet could attenuate skeletal muscle injury induced by diquat toxicity. It is suggested that taurine could be a potential nutritional intervention strategy to improve growth performance.
基金financially supported by the National Basic Research Program of China(2013CB127305)the Nature Science Foundation of Hunan Province(S2014J504I)+1 种基金the Major Project of Hunan Province(2015NK1002)the National Science and Technology Ministry(2014BAD08B11)
文摘Background： To investigate the effects of dietary crude protein（CP） restriction on muscle fiber characteristics and key regulators related to protein deposition in skeletal muscle, a total of 18 growing-finishing pigs（62.30 ± 0.88 kg）were allotted to 3 groups and fed with the recommended adequate protein（AP, 16 % CP） diet, moderately restricted protein（MP, 13 % CP） diet and low protein（LP, 10 % CP） diet, respectively. The skeletal muscle of different locations in pigs, including longissimus dorsi muscle（LDM）, psoas major muscle（PMM） and biceps femoris muscle（BFM） were collected and analyzed.Results： Results showed that growing-finishing pigs fed the MP or AP diet improved（P 〈 0.01） the average daily gain and feed： gain ratio compared with those fed the LP diet, and the MP diet tended to increase（P = 0.09） the weight of LDM. Moreover, the ATP content and energy charge value were varied among muscle samples from different locations of pigs fed the reduced protein diets. We also observed that pigs fed the MP diet up-regulated（P 〈 0.05） muscular m RNA expression of all the selected key genes, except that myosin heavy chain（My HC） IIb,My HC IIx, while m RNA expression of ubiquitin ligases genes was not affected by dietary CP level. Additionally, the activation of mammalian target of rapamycin complex 1（m TORC1） pathway was stimulated（P 〈 0.05） in skeletal muscle of the pigs fed the MP or AP diet compared with those fed the LP diet.Conclusion： The results suggest that the pigs fed the MP diet could catch up to the growth performance and the LDM weight of the pigs fed the AP diet, and the underlying mechanism may be partly due to the alteration in energy status, modulation of muscle fiber characteristics and m TORC1 activation as well as its downstream effectors in skeletal muscle of different locations in growing-finishing pigs.
基金supported by National Natural Science Foundation of China(31972582,U22A20516)Science and Technology Innovation Program of Hunan Province(2021RC4039)+1 种基金Key R&D Program of Hunan Province(2022NK2026)the Youth Innovation Promotion Association CAS(Y202079)
文摘This study was conducted to explore the regulatory mechanism of leucine(Leu)on lipid metabolism of finishing pigs.Twenty-four Duroc×Landrace×Large cross pigs with an average body weight of68.33±0.97 kg were randomly allocated into 3 treatment groups with 8 replicates per group(1 pig per replicate).The dietary treatments were as follows:control group(CON),0.25%Leu group and 0.50%Leu group.The experimental period was 42 d.The results showed as follows.(1)Compared with the CON,0.25%and 0.50%Leu increased(P<0.01)the average daily gain(ADG),while the average backfat thickness(ABT)and the ratio of feed intake to body weight gain(F:G ratio)were decreased(P<0.05).(2)In the 0.25%Leu group,the relative mRNA expression levels of sterol regulatory element binding protein-1c(SREBP1c),recombinant fatty acid transport protein 1(FATP1),chemerin and peroxisome proliferatoractivated receptorγ(PPARγ)were decreased but the level of fatty acid binding protein 4(FABP4)and fatty acid translocase(FAT/CD36)were increased in backfat tissue.In the 0.25%Leu group,the protein levels of p-Rictor,p-Raptor,p-eIF4E-binding protein 1(p-4EBP1),p-silent mating type information regulator 2homolog 1(p-SIRT1)and acetylation ribosome s6 protein kinase 1(Ac—S6K1)were increased(P<0.05).(3)Compared to the CON,the diversity of gut microbiota in the 0.25%Leu group was increased.Principal component analysis showed that the relative abundance of Bacteroidetes,Lactobacillus and Desulfovibrio was higher in the 0.25%Leu group than the CON,but the relative abundance of Firmicutes,Treponema and Shigella was lower than in the CON(P<0.05).(4)Four different metabolites were screened out from the serum of finishing pigs including allolithocholic acid(alloLCA),isolithocholic acid(isoLCA),ursodeoxycholic acid(UDCA)and hyodeoxycholic acid(HDCA),which correlate to various degrees with the above microorganisms.In conclusion,Leu could promote adipose tissue lipolysis of finishing pigs through the mTOR-SIRT1 signaling pathway,and S6K1 is acetylated at the same time,and the interaction between gut microbiota and bile acid metabolism is also involved.
基金China Postdoctoral Science Foundation(2019M652772)Hunan Provincial Natural Science Foundation of China(2017JJ3137)+2 种基金National Natural Science Foundation of China(31601954,31872991)Key Project of Hunan Provincial Education Department(16A096)Earmarked Fund for China Agricultural Research System(CARS-35).
文摘This study evaluated the potential of mulberry leaf powder as an unconventional feed material for fin-ishing pigs by assessing the growth performance,antioxidative properties,fatty acid profile,and lipid metabolism in 180 Xiangcun black pigs.Pigs with an initial body weight(BW)of 71.64±1.46 kg were randomly assigned to 5 treatment groups,including the control diet and 4 experimental diets.The corn,soybean meal,and wheat bran in the control diet were partly replaced by 3%,6%,9%,or 12%mulberry leaf powder in experimental diets.There were 6 replicates(pens)of 6 pigs per replicate in each treatment.Blood and muscle samples were collected after the 50-day feed experiment.Compared with the control group,the 3%,6%,and 9%mulberry diets had no adverse effect(P>0.05)on the growth performance of pigs.The serum glutathione peroxidase activity and glutathione concentration increased linearly(P<0.05)with the increase in dietary mulberry inclusion.There was no significant difference in the relative expression levels of antioxidant-related genes in muscle tissue between the control and mul-berry groups.Inclusion of dietary mulberry powder increased(P<0.05)the content of polyunsaturated fatty acids,especially in the longissimus dorsi(LD)muscle,up-regulated(P<0.05)the relative mRNA expression level of uncoupling protein-3 in muscle tissue,but down-regulated(P<0.05)the relative mRNA expression levels of hormone-sensitive lipase,acetyl CoA carboxylaseα,lipoprotein lipase,and peroxisome proliferator-activated receptor y in LD in a linear pattern.The nuclear respiratory factor 2 expression level in the LD muscle of pigs fed the 9%mulberry diet was higher(P<0.01)than that in the other mulberry groups and control group.The inclusion of less than 12%dietary mulberry did not detrimentally affect the growth performance of Xiangcun black pigs,but enhanced the serum antioxidant property,increased the polyunsaturated fatty acid content,and inhibited lipid oxidation by regulating gene expression levels of lipid metabolism and mitochondrial uncoupling protein in muscle tissue.Mulberry leaves can be utilized as a forage crop in the diet of finishing pigs.
基金National Key Research and Development Program of China(2018YFD0500405)Youth Innovation Promotion Association CAS,Open Fund of Key Laboratory of Agro-ecological Processes in Subtropical Region,Chinese Academy of Sciences(ISA2018304)the earmarked fund for China Agriculture Research System(CARS-35).
文摘Serine and glycine are 2 of the first-affected nonessential amino acids in low crude protein(CP)diets for pigs.Therefore,we explored the effects of different dietary serine-to-glycine ratios on growth perfor-mance and lipid metabolism in growing-finishing pigs.A total of 160 crossbred healthy barrows,with a similar body weight of around 59.50 kg,were randomly allotted into 1 of 5 treatments(8 pens per treatment and 4 pigs per pen).The serine-to-glycine ratios of the 5 dietary treatments were as follows:diet A(NORMAL group),1.18∶1(16%CP);diet B(LOW group),1.2∶1(12%CP);diet C(S2G1 group),2∶1(12%CP);diet D(S1G2 group),1∶2(12%CP);and diet E(S1G1 group),1∶1(12%CP).We found that the pigs fed a low CP diet(12%CP),when maintaining serine-to-glycine ratio at 1∶2 and a total amount of 1.44%,had the same average daily gain as the pigs fed a normal CP diet(16%CP)(P>0.05),but they had increased intramuscular fat(P<0.05).Furthermore,they exhibited higher expression of genes involved in lipid oxidation(P<0.05),which was regulated by modulating methylation levels in the promoters of acyl-CoA oxidase 1(ACOX1)and acyl-CoA dehydrogenase medium chain(ACADM).When compared with the pigs fed a normal CP diet,these pigs had more oxidative myofibers(P<0.05),which were regulated by AMPK-PGC-1αand Calcineurin-MEF2/NFAT pathways in a coordinated manner.Our findings suggested that a dietary serine-to-glycine ratio of 1:2 is beneficial for improving meat quality in pigs fed a low CP diet.
基金jointly supported by the National Natural Science Foundation of China (U19A2037)the Changsha Natural Science Funds for Distinguished Young Scholars (kq2009020)+6 种基金Young Elite Scientists Sponsorship Program by CAST (2020-2022QNRC003)the Natural Science Foundation of Hunan Province (2021JJ20044)the Natural Science Foundation of Guangxi Province (2020JJA130102)China Agriculture Research System of MOF and MARA (CARS-35)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA24030204)the National Key Research and Development Program of China (2022YFD1300503)the Science and Technology Innovation Program of Hunan Province (2022RC1159)。
文摘Pork meat is closely related to physicochemical alterations during growth and development,resulting in differences in nutritional value and meat flavor.This study aimed to evaluate the composition of amino acids,fatty acids,and metabolic profiles in the longissimus thoracis muscle(LM)of Shaziling pigs aged 30,90,150,210,and 300 days.The results showed that the predominant fatty acids identified in the LM of Shaziling pigs were C16:0,C16:1,C18:0,C18:1n9c,and C18:2n6c.An opposite correlation was observed for C18:2n6c and n6/n3 polyunsaturated fatty acids(P<0.05).Alanine,aspartate,glutamate,Dglutamine,and D-glutamate metabolism were the main metabolic pathways for the Shaziling pig meat flavor(P<0.05).Moreover,the correlation coefficients revealed that the contents of anserine,C16:0,C16:1,and C18:1n9c were positively correlated with intramuscular fat and/or p H24hand were negatively correlated with the values of L^(*)(lightness)and b^(*)(yellowness)(P<0.05).In conclusion,age greatly affected the meat quality of Shaziling pigs,and the contents of muscular anserine,C16:0,C16:1,and C18:1n9c might be promising indicators for better meat quality.
基金the National Key R&D Program(2018YFD0500405)the National Nature Science Foundation of China(31972582,U19A2037)+7 种基金the Changsha Natural Science Funds for Distinguished Young Scholar(kq2009020)Special funds for the construction of innovative provinces in Hunan Project(2019NK2193,2019RS3022)Open Fund of Key Laboratory of Agro-ecological Processes in Subtropical Region,Chinese Academy of Sciences(ISA2020203)the‘Strategic Priority Research Program’of the Chinese Academy of Sciences(XDA24030204)the Science and technology projects of Changsha City(kq1801059)Hunan Province Key Laboratory of Animal Nutritional Physiology and Metabolic Process(2018TP1031)the General Program of National Natural Science Foundation of China(31872985)the Earmarked Fund for China Agriculture Research System(CARS-35).
文摘The objective of the study is to evaluate and compare the effects of betaine or glycine on carcass trait,meat quality and lipid metabolism of finishing Huan Jiang mini-pigs.Betaine called trimethylglycine is a methyl derivative of glycine,but few researches were conducted to compare the impact of dietary betaine and glycine on pigs.One hundred and forty-four Huan Jiang mini-pigs(body weight=10.55±0.15 kg;70 d)were randomly divided to 3 treatment groups(basal diet,glycine or betaine).Results indicated that dietary betaine increased the average daily gain(ADG)and final weight(P<0.05).Dietary glycine or betaine markedly reduced average backfat thickness(P<0.05)and heightened lean percentage(P<0.01)compared to the control group.Moreover,in comparison with the control group,betaine significantly improved the redness(a*)and tenderness(shear force)of the longissimus dorsi(LD)muscle(P<0.05),whereas glycine only raised the value of a*of the LD muscle(P<0.05).These results showed that diet supplemented with 0.25%betaine and equimolar amounts of glycine could regulate cascass trait and meat quality of finishing Huan Jiang mini-pigs,and the effect of betaine was superior to that of glycine.
基金supported by National Basic Research Program of China (2013CB127305, 2012CB124704)National Nature Science Foundation of China (31110103909, 31330075)+3 种基金Nature Science Foundation of Hunan (2015JJ2146)The Chinese Academy of Sciences STS Project(KFJ-EW-STS-063)Key Projects in the National Science & Technology Pillar Program (2013BAD21B04)Hunan Province project (2014GK1007)
文摘This experiment was conducted to investigate the effects of branched-chain amino acids(BCAA)supplemented in protein-restricted diets on the growth performance and the expression profile of amino acid transporters and energy metabolism related regulators in the white adipose tissue(WAT)of different regional depots including dorsal subcutaneous adipose(DSA) and abdominal subcutaneous adipose(ASA), A total of 24 crossbred barrows(7.40 ± 0.70 kg) were randomly divided into 4 groups and were fed the following isocaloric diets for 33 days: 1) a recommended adequate protein diet(AP, 20% CP, as a positive control); 2) a low protein diet(LP, 17% CP); 3) the LP diet supplemented with BCAA(LP + B, 17% CP) to reach the same level of the AP diet group; 4) the LP diet supplemented with 2 times the amount of BCAA(LP + 2B, 17% CP). The daily gain and daily feed intake of the LP diet group were the lowest among all the treatments(P < 0.01). The feed conversion was improved markedly in the group of LP + B compared with the LP diet group(P < 0.05). No significant difference was noted for the serum biochemical parameter concentrations of glucose, triglyceride, nonesterified fatty acid and insulin among the groups(P > 0.05). Moreover, BCAA supplementation down-regulated the expression levels of amino acid transporters including L-type amino acid transporter 1 and sodium-coupled neutral amino acid transporter 2 in DSA, but up-regulated the expression level of Ltype amino acid transporter 4 in ASA(P < 0.05), Meanwhile, the energy sensor AMP-activated protein kinase α was activated in the DSA of pigs fed LP diet and in the ASA of the pigs fed AP or LP + 2B diets(P < 0.05). The mRNA expression profile of the selected mitochondrial component and mitochondrial biogenesis associated regulators in DSA and ASA also responded differently to dietary BCAA supplementation. These results suggested that the growth performance of growing pigs fed protein restricted diets supplemented with BCAA could catch up to that of the pigs fed AP diets. The results also partly demonstrated that the regulation mechanisms of BCAA are different in the adipose tissues of different depots.
基金This study was jointly supported by the National Natural Science Foundation of China(U19A2037,31802077)the Changsha Natural Science Funds for Distinguished Young Scholar(kq2009020)+6 种基金the Natural Science Foundation of Guangxi Province(2020JJA130102,2018JJB130239)Young Elite Scientists Sponsorship Program by CAST(2020QNRC001)Special funds for the construction of innovative provinces in Hunan Project(2019NK2193,2019RS3022)China Agriculture Research System of MOF and MARA(CARS-35)the‘Strategic Priority Research Program’of the Chinese Academy of Sciences(XDA24030204)Open Fund of Key Laboratory of Agroecological Processes in Subtropical Region,Chinese Academy of Sciences(ISA2020203)Taishan industry leading talent project special funds.
文摘This study aims to compare the meat quality of Shaziling and Yorkshire pigs and to find the potential indicator in serum for superior meat quality.Six Shaziling and Yorkshire pigs at 30,60,90,150,210,and 300 d of age were selected to examine carcass traits,meat quality,and serum metabolome.The results showed that the body weight,carcass length,and loin eye area of Shaziling pigs at 150,210,and 300 d of age were significantly lower than those of Yorkshire pigs(P<0.05).Shaziling pigs at 150 and 300 d of age had significantly lower backfat thickness than Yorkshire pigs(P<0.05).Compared with Yorkshire pigs,Shaziling pigs at all 6 ages had a lower lean percentage and a higher fat percentage(P<0.05).At 60,90,and 150 d of age,the post-mortem pH-decline,b*value(yellowness),and drip loss of Shaziling pigs were significantly lower than those of Yorkshire pigs(P<0.05).Moreover,at 150 d of age,Shaziling pigs had significantly higher a^(*)value(redness)and intramuscular fat(IMF)content than Yorkshire pigs(P<0.05).Correlation analysis between the top 40 metabolites and phenotypes indicated that L-carnitine had positive correlations with fat percentage,pH24h,and IMF content,but had negative correlations with lean percentage,L^(*)value(lightness),and b^(*)value(P<0.05).Serum L-carnitine content,fat percentage,pH24h,and IMF content all decreased first and then increased as the pigs grew,which verified the positive correlations between L-carnitine and these phenotypes.In conclusion,Shaziling pigs have a slower growth rate but a better meat quality than Yorkshire pigs.The meat quality of Shaziling pigs is the best from 150 to 210 d of age.This study suggests that a higher serum L-carnitine content is a promising indicator for better meat quality.
基金supported by the Zhejiang Provincial Key R&D Program of China(No.2021C02008)the China Agriculture Research System of MOF and MARA(No.CARS-35)+2 种基金the National Natural Science Foundation of China(No.32022079)the Fundamental Research Funds for the Central Universities(No.2022QZJH46)the Taishan Industrial Leading Talents Project.
文摘Engineered probiotics can serve as therapeutics based on their ability of produce recombinant immune-stimulating properties.In this study,we built the recombinant Bacillus subtilis WB800 expressing antimicrobial peptide KR32(WB800-KR32)using genetic engineering methods and investigated its protective effects of nuclear factor-E2-related factor 2(Nrf2)-Kelch-like ECH-associated protein 1(Keap1)pathway activation in intestinal oxidative disturbance induced by enterotoxigenic Escherichia coli(ETEC)K88 in weaned piglets.Twenty-eight weaned piglets were randomly distributed into four treatment groups with seven replicates fed with a basal diet.The feed of the control group(CON)was infused with normal sterilized saline;meanwhile,the ETEC,ETEC+WB800,and ETEC+WB800-KR32 groups were orally administered normal sterilized saline,5×10^(10)CFU(CFU:colony forming units)WB800,and 5×10^(10)CFU WB800-KR32,respectively,on Days 1-14 and all infused with ETEC K881×10^(10)CFU on Days 15-17.The results showed that pretreatment with WB800-KR32 attenuated ETEC-induced intestinal disturbance,improved the mucosal activity of antioxidant enzyme(catalase(CAT),superoxide dismutase(SOD),and glutathione peroxidase(GPx))and decreased the content of malondialdehyde(MDA).More importantly,WB800-KR32 downregulated genes involved in antioxidant defense(GPx and SOD1).Interestingly,WB800-KR32 upregulated the protein expression of Nrf2 and downregulated the protein expression of Keap1 in the ileum.WB800-KR32 markedly changed the richness estimators(Ace and Chao)of gut microbiota and increased the abundance of Eubacterium_rectale_ATCC_33656 in the feces.The results suggested that WB800-KR32 may alleviate ETEC-induced intestinal oxidative injury through the Nrf2-Keap1 pathway,providing a new perspective for WB800-KR32 as potential therapeutics to regulate intestinal oxidative disturbance in ETEC K88 infection.
基金supported by Natural Science Foundation of Hunan Province(No.2021JJ30061)Research foundation of the Education of Hunan Province(18B374)Major Project of Science and Technology Foundation of Hunan Province(No.2015NK1002)。
文摘To study the effects of dietary energy level on the meat quality of different muscles in finishing pigs,400Xiangcun Black pigs(BW=79.55±4.77 kg)were randomly assigned to 5 treatments with varied calculated digestive energy(DE)at 3,050,3,100,3,150,3,200 and 3,250 kcal/kg,respectively.Each treatment had 8replicates with 10 pigs per replicate.Meat quality,amino acid and fatty acid composition were tested in this study.No differences in average daily gain,average daily feed intake or feed-to-gain ratio(P>0.05)were observed among dietary treatments.Glycogen concentrations of longissimus dorsi(LD)muscle in DE3150was higher than those in other groups(P<0.05).The crude fat concentration of biceps femoris(BF)muscle in DE3250 tended to be higher than that in DE3150 and DE3100 groups(P<0.05).Pigs in DE3250 and DE3200 had higher fiber density and smaller cross-sectional area of BF muscle than those in DE3150(P<0.05).Pigs in DE3150 had the highest Cu concentration in LD muscle compared with those in DE3200,DE3250(P<0.05).The C16:1 proportion of LD muscle was lower(P<0.01)and C20:1 was higher(P<0.05)in DE3050 than that in the other dietary treatments.The C18:3n6 and C20:3n6 proportions of BF muscle in DE3150 were higher than those in DE 3050,DE3200 and DE3250(P<0.05).For LD muscle,m RNA expressions of type I and IIa MyHC in group DE3150 were higher than other treatments(P<0.01).The LD muscle in DE3150 expressed higher PPARd than in other groups(P<0.01).Pigs in DE3100 expressed higher FOX1 than in DE3200 and DE3250(P<0.05).Sterol-regulatory element binding proteins(SREBPa)mRNA expression decreased linearly when dietary energy level increased in BF muscle(P<0.01).In conclusion,a200 kcal/kg decrease in digestible energy for 4 consecutive weeks did not affect growth performance of Xiangcun Black pigs.Furthermore,LD and BF muscle respond differently to dietary energy level,and meat quality was improved by the medium energy level during the finishing phase.
基金financially supported by the National Key R&D Program(2018YFD0500405)the Science and technology projects of Changsha City(kq1801059)+2 种基金the STS regional key projects of Chinese Academy of Sciences(KFJ-STS-QYZD-052)the Youth Innovation Promotion Association CAS(2016326)the Earmarked Fund for China Agriculture Research System(CARS-35)
文摘Sodium-coupled neutral amino acid transporter 2(SNAT2),also known as solute carrier family 38 member 2(SLC38 A2),is expressed in the skeletal muscle.Our research previously indicated that SNAT2 m RNA expression level in the skeletal muscle was modulated by genotype and dietary protein.The aim of this study was to investigate the key role of the amino acid transporter SNAT2 in muscle cell growth,differentiation,and related signaling pathways via SNAT2 suppression using the inhibitor a-methylaminoisobutyric acid(Me AIB).The results showed that SNAT2 suppression down-regulated both the m RNA and protein expression levels of SNAT2 in C2 C12 cells,inhibited cell viability and differentiation of the cell,and regulated the cell distribution in G0/G1 and S phases(P<0.05).Meanwhile,most of the intercellular amino acid content of the cells after Me AIB co-culturing was significantly lower(P<0.05).Furthermore,the m RNA expression levels of system L amino acid transporter 1(LAT1),silent information regulator 1,and peroxisome proliferator-activated receptor-gamma co-activator 1 alpha,as well as the protein expression levels of amino acid transporters LAT1 and vacuolar protein sorting 34,were all down-regulated.The phosphorylated protein expression levels of mammalian target of rapamycin(m TOR),regulatory-associated protein of m TOR,4 E binding protein 1,and ribosomal protein S6 kinase 1 after Me AIB treatment were also significantly down-regulated(P<0.05),which could contribute to the importance of SNAT2 in amino acid transportation and skeletal muscle cell sensing.In conclusion,SNAT2 suppression inhibited C2 C12 cell growth and differentiation,as well as the availability of free amino acids.Although the m TOR complex 1 signaling pathway was found to be involved,its response to different nutrients requires further study.
基金supported by National Basic Research Program of China (2012CB124704,2013CB127305)National Nature Science Foundation of China (31372325,31110103909, 31330075)+1 种基金Key Projects in the National Science & Technology Pillar Program (2013BAD21B04)The Chinese Academy of Science STS Project (KFJ-EW-STS-063)
文摘Interleukin-15(IL-15) is a cytokine highly expressed in skeletal muscle. The objective of the present study was to investigate the development of muscle IL-15 expression in suckling piglets and in early weaning piglets(day 14) at each level, that is, mRNA, protein, and secretion. Eight litters(eight piglets per litter) of newborn healthy piglets(Large × White × Landrace) with a similar initial weight(1618.0 ± 140.1 g) were chosen and divided into two groups, Group one used suckling piglets that were killed, respectively, at days 1,7,14,21, and group two used early(day 14) weaning piglets that were killed respectively, at days 15, 17, 19, 21. In group one, IL-15 gene expression levels increased significantly(P < 0.05) along with increased body weight over time. IL-15 protein expression levels in piglets at day 21 of age were higher(P < 0.05) than those in piglets at other ages, and there was no difference(P > 0.05)among piglets at other ages. These findings indicated that increased IL-15 mRNA expression did not result in a corresponding increase of its protein expression. In group two, which used early weaning piglets from days 15-19, IL-15 mRNA and protein expression levels increased constantly(P < 0.05) and were higher(P < 0.05) than those in suckling piglets. Moreover, there was no gain of body weight(P > 0.05) compared with suckling piglets at day 14 of age. However, IL-15 protein expression levels in early weaning piglets at day 21 of age dropped significantly(P < 0.05) to the levels as suckling piglets at day 21 of age, while body weight increased(P < 0.05) markedly to the levels as suckling piglets at day 21 of age. In both groups, the serum IL-15 levels of piglets decreased significantly(P < 0.01) over time. Taken together, our results indicate that IL-15 expression differs in suckling piglets and in weaning piglets. It is speculated that IL-15 may play an important role in counteracting the effects of early weaning stress.
基金supported by the National Natural Science Foundation of China(32372925)the Science and Technology Innovation Program of Hunan Province(2022RC1159)+2 种基金the Changsha Natural Science Funds for Distinguished Young Scholar(kq2009020)the National Key Research and Development Programs of China(2022YFD1300503)the China Agriculture Research System of MOF and MARA(CARS35)。
文摘We previously demonstrated that lipopolysaccharide(LPS)injection-induced immune stress could impair muscle growth in weaned piglets,but the precise mechanisms behind this remain elusive.Here,we found that chronic immune stress induced by LPS resulted in a significant reduction of 36.86%in the total muscle mass of piglets at 5 d post-treatment compared with the control group.At 1 d,prior to muscle mass loss,multiple alterations were noted in response to LPS treatment.These included a reduction in the abundance of Bacteroidetes,an increase in serum concentrations of pro-inflammatory cytokines,compromised mitochondrial morphology,and an upregulation in the expression of dynamin-related protein 1(Drp1),a critical protein involved in mitochondrial fission.We highlight a strong negative correlation between Bacteroidetes abundance and the levels of serum pro-inflammatory cytokines,corroborated by in vivo intervention strategies in the musculature of both pig and mouse models.Mechanistically,the effects of Bacteroidetes on inflammation and muscle mass loss may involve the signaling pathway of the tauro-β-muricholic acid-fibroblast growth factor 15.Furthermore,the induction of overexpression of inflammatory cytokines,achieved without LPS treatment through oral administration of recombinant human IL-6(rh IL-6),led to increased levels of circulating cytokines,subsequently causing a decrease in muscle mass.Notably,pre-treatment with Mdivi-1,an inhibitor of Drp-1,markedly attenuated the LPS-induced elevation in reactive oxygen species levels and rescued the associated decline in muscle mass.Collectively,these data indicate that LPS-induced muscle mass loss was linked to the reduction of Bacteroidetes abundance,increased inflammation,and the disruption of mitochondrial morphology.These insights offer promising avenues for the identification of potential therapeutic targets aimed at mitigating muscle mass loss.
基金financially supported by the National Key R&D Program(2018YFD0500405)the National Nature Science Foundation of China(31972582)+3 种基金the Science and Technology Projects of Changsha City(kq1801059)the STS regional key projects of Chinese Academy of Sciences(KFJ-STS-QYZD-052)the Youth Innovation Team Project of ISA,CAS(2017QNCXTD_ZCS)the Earmarked Fund for China Agriculture Research System(CARS-35)
文摘Tea trees have a long history of cultivation and utilization.People in many countries have the habit of drinking tea and choosing green tea,oolong tea,or black tea according to different regions and personal tastes.Tea polyphe nols are a general term for polyphenol co mpounds in tea,and has been shown to have good effects on antioxidant,anti-inflammatory,cancer prevention and regulation of lipid metabolism.Tea polyphenols have been widely used as antioxidants in disease treatment and animal husbandry,but their specific mechanism of action needs to be further clarified and revealed.This review focuses on the definition,classification,antioxidant activity and the regulation of signaling pathways of tea polyphenols.This paper also aims to examine the application of tea polyphenols in human and animal health,providing a scientific basis for this application in addition to proposing future directions for the development of this resource.
基金the National Key Research and Development Program (2016YFD0501204, 2018YFD0500405)the Youth Innovation Promotion Association CAS (2016326)+5 种基金the Science and Technology Projects of Hunan Province (2016SK3022, 2017RS3058)Key Project of Research and Development Plan of Hunan Province (2016NK2170)Science and Technology Projects of Changsha City (kq1801059)Youth Innovation Team Project of ISA, CAS (2017QNCXTD_ZCS)the Key Research Program of the Chinese Academy of Sciences (KFZD-SW-219)the Earmarked Fund for China Agriculture Research System (CARS-35)。
文摘Free radical-induced oxidative stress contributes to the development of metabolic syndromes(Mets), including overweight,hyperglycemia, insulin resistance and pro-inflammatory state. Most free radicals are generated from the mitochondrial electron transport chain;under physiological conditions, their levels are maintained by efficient antioxidant systems. A variety of transcription factors have been identified and characterized that control gene expression in response to oxidative stress status.Natural antioxidant compounds have been largely studied for their strong antioxidant capacities. This review discusses the recent progress in oxidative stress and mitochondrial dysfunction in Mets and highlights the anti-Mets, anti-oxidative, and antiinflammatory effect of polyphenols as potential nutritional therapy.
基金financial support from the Major Project of Hunan Province (2015NK1002)the National Science and Technology Support Program Funding (2012BAD39B03)Key Research and Development Program of Hunan Province(field of agricultural support) (2015NK2004, 2015JC3100)
文摘A 60-days feeding trial was conducted to determine the effect of dietary supplementation of Lonicera macranthoides leaf(LML) on growth performance, meat quality, and free amino acid profiles in growingfinishing pigs. L. macranthoides leaves were harvested, air-dried and milled to powder. A total of 288 crossbred barrows(Large White x Landrace) with an average initial BW of 54.0 ± 3.4 kg were randomly allocated to 3 treatment groups and fed either a basal diet or a diet supplemented with 0.5% or 1.0% LML powder. Results showed that diet supplemented with LML powder did not affect average daily feed intake(ADFI) and feed: gain ratio(P> 0.05) in growing-finishing pigs. Moreover, diet supplemented with LML powder showed no significant effects on carcass traits(P > 0.05) including dressing percentage,backfat thickness and loin muscle area, and meat quality traits(P > 0.05) including meat color, intramuscular fat and cooking loss. However, diet supplemented with LML powder significantly improved free amino acid profiles in serum and longissimus thoracis muscle in growing-finishing pigs. Most importantly, dietary LML powder increased total free amino acids content(P < 0.001) and essential free amino acid content(P < 0.001) in longissimus thoracis muscle. These results indicate that LML has the potential to improve the nutritional value of meat through improving free amino acid profiles.
