Background The energy/protein imbalance in a low-protein diet induces lipid metabolism disorders in late-phase laying hens.Reducing energy levels in the low-protein diet to adjust the energy-to-protein ratio may impro...Background The energy/protein imbalance in a low-protein diet induces lipid metabolism disorders in late-phase laying hens.Reducing energy levels in the low-protein diet to adjust the energy-to-protein ratio may improve fat deposition,but this also decreases the laying performance of hens.This study investigated the mechanism by which different energy levels in the low-protein diet influences liver lipid metabolism in late-phase laying hens through the enterohepatic axis to guide feed optimization and nutrition strategies.A total of 288 laying hens were randomly allocated to the normal-energy and normal-protein diet group(positive control:CK)or 1 of 3 groups:lowenergy and low-protein diet(LL),normal-energy and low-protein diet(NL),and high-energy and low-protein diet(HL)groups.The energy-to-protein ratios of the CK,LL,NL,and HL diets were 0.67,0.74,0.77,and 0.80,respectively.Results Compared with the CK group,egg quality deteriorated with increasing energy intake in late-phase laying hens fed low-protein diet.Hens fed LL,NL,and HL diets had significantly higher triglyceride,total cholesterol,acetylCo A carboxylase,and fatty acid synthase levels,but significantly lower hepatic lipase levels compared with the CK group.Liver transcriptome sequencing revealed that genes involved in fatty acid beta-oxidation(ACOX1,HADHA,EHHADH,and ACAA1)were downregulated,whereas genes related to fatty acid synthesis(SCD,FASN,and ACACA)were upregulated in LL group compared with the CK group.Comparison of the cecal microbiome showed that in hens fed an LL diet,Lactobacillus and Desulfovibrio were enriched,whereas riboflavin metabolism was suppressed.Cecal metabolites that were most significantly affected by the LL diet included several vitamins,such as riboflavin(vitamin B2),pantethine(vitamin B5 derivative),pyridoxine(vitamin B6),and 4-pyridoxic acid.Conclusion A lipid metabolism disorder due to deficiencies of vitamin B2 and pantethine originating from the metabolism of the cecal microbiome may be the underlying reason for fat accumulation in the liver of late-phase laying hens fed an LL diet.Based on the present study,we propose that targeting vitamin B2 and pantethine(vitamin B5 derivative)might be an effective strategy for improving lipid metabolism in late-phase laying hens fed a low-protein diet.展开更多
[Objectives]To explore the effects of Abrus cantoniensis Hance(ACH)extract on blood lipid indicators of laying hen fed with high energy and low protein diet.[Methods]Sixty 90-day-old laying hens were randomly divided ...[Objectives]To explore the effects of Abrus cantoniensis Hance(ACH)extract on blood lipid indicators of laying hen fed with high energy and low protein diet.[Methods]Sixty 90-day-old laying hens were randomly divided into five groups:the blank control group(basic diet),the model group(high-energy and low-protein diet,HELPD),the low-dose group(HELPD+0.5 g ACH extract per hen,LACH),and the medium-dose group(HELPD+1 g ACH extract per hen,MACH),high dose group(HELPD+2 g ACH extract per hen,HACH).The ACH extract was administrated by drinking water for 48 d.[Results]Different doses of ACH could improve the pathological changes induced by high energy and low protein.ACH extract had no significant effect on blood routine indicators of laying hens(P>0.05).The contents of total cholesterol(TC),triglyceride(TG)and low density lipoprotein cholesterol(LDL-C)in the model group were significant-ly higher than those in the control group(P<0.05),while the content of high density lipoprotein cholesterol(HDL-C)was significantly lower than that in the control group(P<0.05).There was no significant difference in blood lipid between LACH group and model group(P>0.05).In MACH and HACH groups,the contents of TC,TG and LDL-C were significantly lower than those in the model group(P<0.05),and the content of HDL-C was significantly higher than that in the model group(P<0.05).[Conclusions]The ACH extract can regulate theHELPD-induced dyslipidemia in laying hens.展开更多
The California least tern (Sternula antillarum browni) is an endangered species. The two largest colonies of this bird species in the San Francisco Bay, California, USA, are located 23 km apart at Alameda Point and ...The California least tern (Sternula antillarum browni) is an endangered species. The two largest colonies of this bird species in the San Francisco Bay, California, USA, are located 23 km apart at Alameda Point and Hayward Regional Shoreline. The Alameda Point colony, on the former Naval Air Station, Alameda, has grown at an average rate of 9.2% per year since its discovery in 1976 and has a nesting density ranging from 1-153 nests per ha. Long-term breeding success at Alameda has averaged 0.86 fledglings per breeding pair. Least tems began appearing in 2003, at an island in Hayward enhanced with substrate mediums and social attraction devices. Successful breeding attempts have been observed at the Hayward colony since 2006. The Hayward colony has grown at an average rate of 51.5% per year, has a nesting density ranging from 33-333 nests per ha and long-term breeding success average of 0.87 fledglings per breeding pair. Dropped fish have been collected from both colonies, and silversides (family Atherinopsidae) are the dominant prey. Alameda terns forage on a greater variety of species than the Hayward terns. The regression results indicate the importance of Northern anchovy (Engraulis mordax) to the breeding success of the Alameda colony.展开更多
Background:High-protein diets can increase the colonic health risks.A moderate reduction of dietary crude-protein(CP)level can improve the colonic bacterial community and mucosal immunity of pigs.However,greatly reduc...Background:High-protein diets can increase the colonic health risks.A moderate reduction of dietary crude-protein(CP)level can improve the colonic bacterial community and mucosal immunity of pigs.However,greatly reducing the dietary CP level,even supplemented with all amino acids(AAs),detrimentally affects the colonic health,which may be due to the lack of protein-derived peptides.Therefore,this study evaluated the effects of supplementation of casein hydrolysate(peptide source)in low-protein(LP)diets,in comparison with AAs supplementation,on the colonic microbiota,microbial metabolites and mucosal immunity in pigs,aiming to determine whether a supplementation of casein hydrolysate can improve colonic health under very LP level.Twenty-one pigs(initial BW 19.90±1.00 kg,63±1 days of age)were assigned to three groups and fed with control diet(16%CP),LP diets(13%CP)supplemented with free AAs(LPA)or casein hydrolysate(LPC)for 4 weeks.Results:Compared with control diet,LPA and LPC diet decreased the relative abundance of Streptococcus and Escherichia coli,and LPC diet further decreased the relative abundance of Proteobacteria.LPC diet also increased the relative abundance of Lactobacillus reuteri.Both LP diets decreased concentrations of ammonia and cadaverine,and LPC diet also reduced concentrations of putrescine,phenol and indole.Moreover,LPC diet increased total short-chain fatty acid concentration.In comparison with control diet,both LP diets decreased protein expressions of Toll-like receptor-4,nuclear factor-κB,interleukin-1βand tumor necrosis factor-α,and LPC diet further decreased protein expressions of nucleotide-binding oligomerization domain protein-1 and interferon-γ.LPC diet also increased protein expressions of G-protein coupled receptor-43,interleukin-4,transforming growth factor-β,immunoglobulin A and mucin-4,which are indicators for mucosal defense activity.Conclusions:The results showed that supplementing casein hydrolysate showed beneficial effects on the colonic microbiota and mucosal immunity and barrier function in comparison with supplementing free AAs in LP diets.These findings may provide new framework for future nutritional interventions for colon health in pigs.展开更多
A study was conducted to evaluate production performance of minks in growing-furring period with supplementing DL-Methinnine (Met) in low protein diet. Seventy healthy male minks were randomly divided into five grou...A study was conducted to evaluate production performance of minks in growing-furring period with supplementing DL-Methinnine (Met) in low protein diet. Seventy healthy male minks were randomly divided into five groups of 14 minks each. The minks were fed in five kinds of experiment diets (HP, LP, LP+M1, LP+M2 and LP+M3). The dietary protein levels, expressed as percentage of dry matter (DM), were 32% (high protein, HP) and 24% (low protein, LP). LP was supple- mented with Met 0.4% (M1), 0.8% (M2) and 1.2% (M3) DM. From mid of September to December 10, apparent digestibility of CP (crude pro- tein), N intake and urinary N excretion were decreased with declining dietary protein levels (p 〈 0.05) and N retained was the highest in treat- ment LP+M2. No significant difference was found in total serum protein (TP) and serum urea nitrogen (SUN) among all treatment groups (p 〉 0.05). Skin length of treatment HP and LP^M2 was higher than that of other groups (p 〈 0.05). Body length, skin weight, length of guard hair and under hair were not affected by different dietary protein levels (p〉0.05). The best performance could be observed in treatment LP+M2. In diet, 24% (DM) protein level with 1.54% Met supplementing was enough for minks during growing-farring period. Dietary protein lowered from 32% to 24% with supplementing Met in diets would result in a37.9% decrease in urinary N excretion. Furthermore, addition of Met in diets for minks would be beneficial in terms of reducing feed expenses and lessening nitrogen emissions to the environment.展开更多
Background:Identifying regulatory measures to promote glucose oxidative metabolism while simultaneously reducing amino acid oxidative metabolism is one of the foremost challenges in formulating low-protein(LP)diets de...Background:Identifying regulatory measures to promote glucose oxidative metabolism while simultaneously reducing amino acid oxidative metabolism is one of the foremost challenges in formulating low-protein(LP)diets designed to reduce the excretion of nitrogen-containing substances known to be potential pollutants.In this study,we investigated the effects of adding sodium dichloroacetate(DCA)to a LP diet on nitrogen balance and amino acid metabolism in the portal-drained viscera(PDV)and liver of pigs.To measure nitrogen balance,18 barrows(40±1.0 kg)were fed one of three diets(n=6 per group):18%crude protein(CP,control),13.5%CP(LP),and 13.5%CP+100 mg DCA/kg dry matter(LP-DCA).To measure amino acid metabolism in the PDV and liver,15 barrows(40±1.0 kg)were randomly assigned to one of the three diets(n=5 per group).Four essential amino acids(Lys,Met,Thr,and Trp)were added to the LP diets such that these had amino acid levels comparable to those of the control diet.Results:The LP-DCA diet reduced nitrogen excretion in pigs relative to that of pigs fed the control diet(P<0.05),without any negative effects on nitrogen retention(P>0.05).There were no differences between the control and LP-DCA groups with respect to amino acid supply to the liver and extra-hepatic tissues in pigs(P>0.05).The net release of ammonia into the portal vein and production rate of urea in the liver of pigs fed the LP-DCA diet was reduced relative to that of pigs fed the control and LP diets(P<0.05).Conclusion:The results indicated that addition of DCA to a LP diet can efficiently reduce nitrogen excretion in pigs and maximize the supply of amino acids to the liver and extra-hepatic tissues.展开更多
The shortage of protein feed resources and environmental pollution restrict the healthy and sustainable development of breeding industry,so it is imperative to promote low protein diet. Based on the current industry t...The shortage of protein feed resources and environmental pollution restrict the healthy and sustainable development of breeding industry,so it is imperative to promote low protein diet. Based on the current industry trends and national policies, this paper analyzes the background con-ditions, significance and specific measures of popularizing low-protein diets, in order to provide policy, theoretical and technical support for the im-plementation of low-protein diets throughout the year.展开更多
Low protein intake causes a decrease in protein deposition in most animal tissues. The purpose of this study was to investigate whether leucine supplementation would increase the synthesis rate of protein and muscle w...Low protein intake causes a decrease in protein deposition in most animal tissues. The purpose of this study was to investigate whether leucine supplementation would increase the synthesis rate of protein and muscle weight in adult rats, which chronically consume only 58.8% of their protein requirements. Thirty-six male Sprague-Dawley rats were assigned to one of three dietary treatments including a 20% casein diet (CON), a 10% casein + 0.44% alanine diet (R), and a 10% casein + 0.87% leucine diet (RL). After a 10 d dietary treatment, plasma amino acid levels were measured after feeding, the gastrocnemius muscles and soleus muscles were harvested and weighed, and the fractional synthesis rate (FSR) and mammalian target of rapamycin (mTOR) signaling proteins in skeletal muscle were measured. Regarding the plasma amino acid level, the RL group had the highest concentration of leucine (P 〈 0.05) and the lowest concentration of isoleucine (P 〈 0.05) among the three groups, and the CON group had a lower concentration of valine (P 〈 0.05) than the R and RL groups. Compared with the R and RE groups, the CON group diet significantly increased (P 〈 0.05) feed intake, protein synthesis rate, and the phosphorylation of eukaryutic initiation factor 4E binding protein 1 (4E-BP1), and decreased the weight of abdominal adipose. Compared with the R group, the RL group significantly increased in gastrocnemius muscle weight, protein synthesis rate, and phosphorylation of both ribosomal protein $6 kinase 1 (56K1) and 4E-BP1. In conclusion, when protein is chronically restricted in adult rat diets, leucine supplementation moderately improves body weight gain and increases muscle protein synthesis through mTOR activation,展开更多
Background:Protein releases amino acids faster than starch releases glucose in digestive tract of pigs fed lowprotein(LP)diets.Poor synchronization of dietary glucose and amino acids supply leads to compromised nitrog...Background:Protein releases amino acids faster than starch releases glucose in digestive tract of pigs fed lowprotein(LP)diets.Poor synchronization of dietary glucose and amino acids supply leads to compromised nitrogen efficiency.Dietary starch patterns modulation may improve this situation.Methods:Growing barrows(29.7±2.0 kg)were randomly allotted into 5 dietary treatments with LP diets consisting of different purified starches.Treatments included:waxy corn starch(W LP),corn starch+waxy corn starch(C+W LP),corn starch(C LP),pea starch+waxy corn starch(P+W LP)and pea starch(P LP).In the experiment,growth performance,protein deposition,nutrient metabolism,and fecal microbial community of pigs were investigated.In vitro starch digestion was used for predicting the in vivo glucose response.Results:Dietary starch in vitro glucose release profile was determined by starch source and the ratio of amylopectin and amylose.C+W LP treatment showed decreased total nitrogen excretion and plasma citrulline concentration and improved plasma leptin concentration among treatments(P<0.05).Besides,the highest nitrogen apparent biological value,whole-body protein deposition and growth performance and lowest urinary nitrogen excretion were also observed in C+W LP treatment.Compared with the other groups,C+W LP and C LP showed increased plasma pyruvate,IGF-1,and lipase concentrations(P<0.05).The W LP group presented dramatically increased plasma alanine and urea nitrogen concentration and decreased aldolase and leptin concentrations(P<0.05).Dietary starch patterns did not make an impact on bacterial richness and diversity,but changed the taxonomic and functional structures of the microbial communities.Microbial protein fermentation product(isobutyrate and isovalerate)presented increased in P LP treatments compared with the other treatments(P<0.05).Conclusions:Dietary starch patterns modulation can regulate dietary glucose release profile,nutrient metabolism,protein turnover,and fecal microbial fermentation in pigs.The optimal dietary glucose release profile effectively strengthened whole-body protein deposition and improve nitrogen efficiency and growth performance in growing pigs fed LP diets.展开更多
Background: Sympatric species adapt to, and temporally or geographically segregate access to similar limiting factors.Methods: We compared nesting habitat and diet affinities of six raptor species in central India bet...Background: Sympatric species adapt to, and temporally or geographically segregate access to similar limiting factors.Methods: We compared nesting habitat and diet affinities of six raptor species in central India between the years 20062015.Results: A large composition of reptiles in the diet was characteristic for Circaetus gallicus, Spilornis cheela and Elanus caeruleus, while Aquila fasciata, Falco chicquera and Nisaetus cirrhatus show a higher proportion of birds. Species with greatest similarity of diet were C. gallicus and S. cheela. Considering the environmental characterization of areas where raptors built the nest, some species were ecologically closer than others. N. cirrhatus and S. cheela were related to the presence of water bodies, dry deciduous forest and evergreen forests, while E. caeruleus and C. gallicus preferred more open habitats. A. fasciata bred either on cliffs or trees, F. chicquera on trees or mobile towers, and the other four species built their nests exclusively in trees.Conclusions: We conclude that although there was overlap in diet and nesting ecology for a number of species, the geographical separation likely limits competition for resources.展开更多
Dietary nutrient manipulation(e.g.protein fractions)could lower the environmental footprints of ruminants,especially reactive nitrogen(N).This study investigated the impacts of dietary soluble protein(SP)levels with d...Dietary nutrient manipulation(e.g.protein fractions)could lower the environmental footprints of ruminants,especially reactive nitrogen(N).This study investigated the impacts of dietary soluble protein(SP)levels with decreased crude protein(CP)on intestinal N absorption,hindgut N metabolism,fecal microbiota and metabolites,and their linkage with N metabolism phenotype.Thirty-two male Hu sheep,with an age of six months and an initial BW of 40.37±1.18 kg,were randomly assigned to four dietary groups.The control diet(CON),aligning with NRC standards,maintained a CP content of 16.7%on a dry matter basis.Conversely,the experimental diets(LPA,LPB,and LPC)featured a 10%reduction in CP compared with CON,accompanied by SP adjustments to 21.2%,25.9%,and 29.4%of CP,respectively.Our results showed that low-protein diets led to significant reductions in the concentrations of plasma creatinine,ammonia,urea N,and fecal total short-chain fatty acids(SCFA)(P<0.05).Notably,LPB and LPC exhibited increased total SCFA and propionate concentrations compared with LPA(P<0.05).The enrichment of the Prevotella genus in fecal microbiota associated with energy metabolism and amino acid(AA)biosynthesis pathways was evident with SP levels in low-protein diets of approximately 25%to 30%.Moreover,LPB and LPC diets demonstrated a decrease in fecal NH_(4)^(+) eN and NO_(2) eN contents as well as urease activity,compared with CON(P<0.05).Concomitantly,reductions in fecal glutamic acid dehydrogenase gene(gdh),nitrite reductase gene(nirS),and nitric oxide reductase gene(norB)abundances were observed(P<0.05),pointing towards a potential reduction in reactive N production at the source.Of significance,the up-regulation of mRNA abundance of AA and peptide transporters in the small intestine(duodenum,jejunum,and ileum)and the elevated concentration of plasma AA(e.g.arginine,methionine,aspartate,glutamate,etc.)underscored the enhancement of N absorption and N efficiency.In summary,a 10%reduction in CP,coupled with an SP level of approximately 25%to 30%,demonstrated the potential to curtail reactive N emissions through fecal Prevotella enrichment and improve intestinal energy and N utilization efficiency.展开更多
基金supported by China Agriculture Research System(No.CARS-40-S25)National Key R&D Program of China(No.2022YFD1601905)+1 种基金the Industrial Innovation Talent Project of the“Xing Dian Talent Support Program”of Yunnan Province in 2022(XDYC-CYCX-2022–0029)the Young Talent Project of the“Xing Dian Talent Support Program”of Yunnan Province in 2023。
文摘Background The energy/protein imbalance in a low-protein diet induces lipid metabolism disorders in late-phase laying hens.Reducing energy levels in the low-protein diet to adjust the energy-to-protein ratio may improve fat deposition,but this also decreases the laying performance of hens.This study investigated the mechanism by which different energy levels in the low-protein diet influences liver lipid metabolism in late-phase laying hens through the enterohepatic axis to guide feed optimization and nutrition strategies.A total of 288 laying hens were randomly allocated to the normal-energy and normal-protein diet group(positive control:CK)or 1 of 3 groups:lowenergy and low-protein diet(LL),normal-energy and low-protein diet(NL),and high-energy and low-protein diet(HL)groups.The energy-to-protein ratios of the CK,LL,NL,and HL diets were 0.67,0.74,0.77,and 0.80,respectively.Results Compared with the CK group,egg quality deteriorated with increasing energy intake in late-phase laying hens fed low-protein diet.Hens fed LL,NL,and HL diets had significantly higher triglyceride,total cholesterol,acetylCo A carboxylase,and fatty acid synthase levels,but significantly lower hepatic lipase levels compared with the CK group.Liver transcriptome sequencing revealed that genes involved in fatty acid beta-oxidation(ACOX1,HADHA,EHHADH,and ACAA1)were downregulated,whereas genes related to fatty acid synthesis(SCD,FASN,and ACACA)were upregulated in LL group compared with the CK group.Comparison of the cecal microbiome showed that in hens fed an LL diet,Lactobacillus and Desulfovibrio were enriched,whereas riboflavin metabolism was suppressed.Cecal metabolites that were most significantly affected by the LL diet included several vitamins,such as riboflavin(vitamin B2),pantethine(vitamin B5 derivative),pyridoxine(vitamin B6),and 4-pyridoxic acid.Conclusion A lipid metabolism disorder due to deficiencies of vitamin B2 and pantethine originating from the metabolism of the cecal microbiome may be the underlying reason for fat accumulation in the liver of late-phase laying hens fed an LL diet.Based on the present study,we propose that targeting vitamin B2 and pantethine(vitamin B5 derivative)might be an effective strategy for improving lipid metabolism in late-phase laying hens fed a low-protein diet.
基金Supported by Special Project of Technological Innovation of Hainan Provincial Research Institute(SQKY2022-0006)Key Task of the Institute of Animal Husbandry and Veterinary of Hainan Agricultural Academy(HNXM2024ZD01).
文摘[Objectives]To explore the effects of Abrus cantoniensis Hance(ACH)extract on blood lipid indicators of laying hen fed with high energy and low protein diet.[Methods]Sixty 90-day-old laying hens were randomly divided into five groups:the blank control group(basic diet),the model group(high-energy and low-protein diet,HELPD),the low-dose group(HELPD+0.5 g ACH extract per hen,LACH),and the medium-dose group(HELPD+1 g ACH extract per hen,MACH),high dose group(HELPD+2 g ACH extract per hen,HACH).The ACH extract was administrated by drinking water for 48 d.[Results]Different doses of ACH could improve the pathological changes induced by high energy and low protein.ACH extract had no significant effect on blood routine indicators of laying hens(P>0.05).The contents of total cholesterol(TC),triglyceride(TG)and low density lipoprotein cholesterol(LDL-C)in the model group were significant-ly higher than those in the control group(P<0.05),while the content of high density lipoprotein cholesterol(HDL-C)was significantly lower than that in the control group(P<0.05).There was no significant difference in blood lipid between LACH group and model group(P>0.05).In MACH and HACH groups,the contents of TC,TG and LDL-C were significantly lower than those in the model group(P<0.05),and the content of HDL-C was significantly higher than that in the model group(P<0.05).[Conclusions]The ACH extract can regulate theHELPD-induced dyslipidemia in laying hens.
文摘The California least tern (Sternula antillarum browni) is an endangered species. The two largest colonies of this bird species in the San Francisco Bay, California, USA, are located 23 km apart at Alameda Point and Hayward Regional Shoreline. The Alameda Point colony, on the former Naval Air Station, Alameda, has grown at an average rate of 9.2% per year since its discovery in 1976 and has a nesting density ranging from 1-153 nests per ha. Long-term breeding success at Alameda has averaged 0.86 fledglings per breeding pair. Least tems began appearing in 2003, at an island in Hayward enhanced with substrate mediums and social attraction devices. Successful breeding attempts have been observed at the Hayward colony since 2006. The Hayward colony has grown at an average rate of 51.5% per year, has a nesting density ranging from 33-333 nests per ha and long-term breeding success average of 0.87 fledglings per breeding pair. Dropped fish have been collected from both colonies, and silversides (family Atherinopsidae) are the dominant prey. Alameda terns forage on a greater variety of species than the Hayward terns. The regression results indicate the importance of Northern anchovy (Engraulis mordax) to the breeding success of the Alameda colony.
基金supported by National Key Basic Research Program of China(2013CB127300)Natural Science Foundation of China(31430082).
文摘Background:High-protein diets can increase the colonic health risks.A moderate reduction of dietary crude-protein(CP)level can improve the colonic bacterial community and mucosal immunity of pigs.However,greatly reducing the dietary CP level,even supplemented with all amino acids(AAs),detrimentally affects the colonic health,which may be due to the lack of protein-derived peptides.Therefore,this study evaluated the effects of supplementation of casein hydrolysate(peptide source)in low-protein(LP)diets,in comparison with AAs supplementation,on the colonic microbiota,microbial metabolites and mucosal immunity in pigs,aiming to determine whether a supplementation of casein hydrolysate can improve colonic health under very LP level.Twenty-one pigs(initial BW 19.90±1.00 kg,63±1 days of age)were assigned to three groups and fed with control diet(16%CP),LP diets(13%CP)supplemented with free AAs(LPA)or casein hydrolysate(LPC)for 4 weeks.Results:Compared with control diet,LPA and LPC diet decreased the relative abundance of Streptococcus and Escherichia coli,and LPC diet further decreased the relative abundance of Proteobacteria.LPC diet also increased the relative abundance of Lactobacillus reuteri.Both LP diets decreased concentrations of ammonia and cadaverine,and LPC diet also reduced concentrations of putrescine,phenol and indole.Moreover,LPC diet increased total short-chain fatty acid concentration.In comparison with control diet,both LP diets decreased protein expressions of Toll-like receptor-4,nuclear factor-κB,interleukin-1βand tumor necrosis factor-α,and LPC diet further decreased protein expressions of nucleotide-binding oligomerization domain protein-1 and interferon-γ.LPC diet also increased protein expressions of G-protein coupled receptor-43,interleukin-4,transforming growth factor-β,immunoglobulin A and mucin-4,which are indicators for mucosal defense activity.Conclusions:The results showed that supplementing casein hydrolysate showed beneficial effects on the colonic microbiota and mucosal immunity and barrier function in comparison with supplementing free AAs in LP diets.These findings may provide new framework for future nutritional interventions for colon health in pigs.
基金supported by Special Fund for Public Welfare Technology Research of Agricultural Industry (200903014)
文摘A study was conducted to evaluate production performance of minks in growing-furring period with supplementing DL-Methinnine (Met) in low protein diet. Seventy healthy male minks were randomly divided into five groups of 14 minks each. The minks were fed in five kinds of experiment diets (HP, LP, LP+M1, LP+M2 and LP+M3). The dietary protein levels, expressed as percentage of dry matter (DM), were 32% (high protein, HP) and 24% (low protein, LP). LP was supple- mented with Met 0.4% (M1), 0.8% (M2) and 1.2% (M3) DM. From mid of September to December 10, apparent digestibility of CP (crude pro- tein), N intake and urinary N excretion were decreased with declining dietary protein levels (p 〈 0.05) and N retained was the highest in treat- ment LP+M2. No significant difference was found in total serum protein (TP) and serum urea nitrogen (SUN) among all treatment groups (p 〉 0.05). Skin length of treatment HP and LP^M2 was higher than that of other groups (p 〈 0.05). Body length, skin weight, length of guard hair and under hair were not affected by different dietary protein levels (p〉0.05). The best performance could be observed in treatment LP+M2. In diet, 24% (DM) protein level with 1.54% Met supplementing was enough for minks during growing-farring period. Dietary protein lowered from 32% to 24% with supplementing Met in diets would result in a37.9% decrease in urinary N excretion. Furthermore, addition of Met in diets for minks would be beneficial in terms of reducing feed expenses and lessening nitrogen emissions to the environment.
基金This study was funded by grants from the National Natural Science Foundation of China(31872370,31670123)the Fundamental Research Funds for the Central Universities(XDJK2019B014,XDJK2013C097)the Natural Science Foundation Project of CQ CSTC(cstc2018jcyjAX0025).
文摘Background:Identifying regulatory measures to promote glucose oxidative metabolism while simultaneously reducing amino acid oxidative metabolism is one of the foremost challenges in formulating low-protein(LP)diets designed to reduce the excretion of nitrogen-containing substances known to be potential pollutants.In this study,we investigated the effects of adding sodium dichloroacetate(DCA)to a LP diet on nitrogen balance and amino acid metabolism in the portal-drained viscera(PDV)and liver of pigs.To measure nitrogen balance,18 barrows(40±1.0 kg)were fed one of three diets(n=6 per group):18%crude protein(CP,control),13.5%CP(LP),and 13.5%CP+100 mg DCA/kg dry matter(LP-DCA).To measure amino acid metabolism in the PDV and liver,15 barrows(40±1.0 kg)were randomly assigned to one of the three diets(n=5 per group).Four essential amino acids(Lys,Met,Thr,and Trp)were added to the LP diets such that these had amino acid levels comparable to those of the control diet.Results:The LP-DCA diet reduced nitrogen excretion in pigs relative to that of pigs fed the control diet(P<0.05),without any negative effects on nitrogen retention(P>0.05).There were no differences between the control and LP-DCA groups with respect to amino acid supply to the liver and extra-hepatic tissues in pigs(P>0.05).The net release of ammonia into the portal vein and production rate of urea in the liver of pigs fed the LP-DCA diet was reduced relative to that of pigs fed the control and LP diets(P<0.05).Conclusion:The results indicated that addition of DCA to a LP diet can efficiently reduce nitrogen excretion in pigs and maximize the supply of amino acids to the liver and extra-hepatic tissues.
基金Supported by Guangzhou key project(201707020007)Guangdong key lab project(2017B030314044)+3 种基金Construction of Provincial Agricultural Industry Extension System(2017LM4164,2018LM2153)Innovation Team Project of Provincial Agricultural Industry Research System in Guangdong Province(2017LM1080,2018 LM1080)International Science and Technology Cooperation Project of Guangdong Province(2014A050503049)National 973 Plan(2013CB127301)
文摘The shortage of protein feed resources and environmental pollution restrict the healthy and sustainable development of breeding industry,so it is imperative to promote low protein diet. Based on the current industry trends and national policies, this paper analyzes the background con-ditions, significance and specific measures of popularizing low-protein diets, in order to provide policy, theoretical and technical support for the im-plementation of low-protein diets throughout the year.
文摘Low protein intake causes a decrease in protein deposition in most animal tissues. The purpose of this study was to investigate whether leucine supplementation would increase the synthesis rate of protein and muscle weight in adult rats, which chronically consume only 58.8% of their protein requirements. Thirty-six male Sprague-Dawley rats were assigned to one of three dietary treatments including a 20% casein diet (CON), a 10% casein + 0.44% alanine diet (R), and a 10% casein + 0.87% leucine diet (RL). After a 10 d dietary treatment, plasma amino acid levels were measured after feeding, the gastrocnemius muscles and soleus muscles were harvested and weighed, and the fractional synthesis rate (FSR) and mammalian target of rapamycin (mTOR) signaling proteins in skeletal muscle were measured. Regarding the plasma amino acid level, the RL group had the highest concentration of leucine (P 〈 0.05) and the lowest concentration of isoleucine (P 〈 0.05) among the three groups, and the CON group had a lower concentration of valine (P 〈 0.05) than the R and RL groups. Compared with the R and RE groups, the CON group diet significantly increased (P 〈 0.05) feed intake, protein synthesis rate, and the phosphorylation of eukaryutic initiation factor 4E binding protein 1 (4E-BP1), and decreased the weight of abdominal adipose. Compared with the R group, the RL group significantly increased in gastrocnemius muscle weight, protein synthesis rate, and phosphorylation of both ribosomal protein $6 kinase 1 (56K1) and 4E-BP1. In conclusion, when protein is chronically restricted in adult rat diets, leucine supplementation moderately improves body weight gain and increases muscle protein synthesis through mTOR activation,
基金financially supported by the Beijing Swine Innovation Team of Modern Agriculture Industry Technological System.
文摘Background:Protein releases amino acids faster than starch releases glucose in digestive tract of pigs fed lowprotein(LP)diets.Poor synchronization of dietary glucose and amino acids supply leads to compromised nitrogen efficiency.Dietary starch patterns modulation may improve this situation.Methods:Growing barrows(29.7±2.0 kg)were randomly allotted into 5 dietary treatments with LP diets consisting of different purified starches.Treatments included:waxy corn starch(W LP),corn starch+waxy corn starch(C+W LP),corn starch(C LP),pea starch+waxy corn starch(P+W LP)and pea starch(P LP).In the experiment,growth performance,protein deposition,nutrient metabolism,and fecal microbial community of pigs were investigated.In vitro starch digestion was used for predicting the in vivo glucose response.Results:Dietary starch in vitro glucose release profile was determined by starch source and the ratio of amylopectin and amylose.C+W LP treatment showed decreased total nitrogen excretion and plasma citrulline concentration and improved plasma leptin concentration among treatments(P<0.05).Besides,the highest nitrogen apparent biological value,whole-body protein deposition and growth performance and lowest urinary nitrogen excretion were also observed in C+W LP treatment.Compared with the other groups,C+W LP and C LP showed increased plasma pyruvate,IGF-1,and lipase concentrations(P<0.05).The W LP group presented dramatically increased plasma alanine and urea nitrogen concentration and decreased aldolase and leptin concentrations(P<0.05).Dietary starch patterns did not make an impact on bacterial richness and diversity,but changed the taxonomic and functional structures of the microbial communities.Microbial protein fermentation product(isobutyrate and isovalerate)presented increased in P LP treatments compared with the other treatments(P<0.05).Conclusions:Dietary starch patterns modulation can regulate dietary glucose release profile,nutrient metabolism,protein turnover,and fecal microbial fermentation in pigs.The optimal dietary glucose release profile effectively strengthened whole-body protein deposition and improve nitrogen efficiency and growth performance in growing pigs fed LP diets.
文摘Background: Sympatric species adapt to, and temporally or geographically segregate access to similar limiting factors.Methods: We compared nesting habitat and diet affinities of six raptor species in central India between the years 20062015.Results: A large composition of reptiles in the diet was characteristic for Circaetus gallicus, Spilornis cheela and Elanus caeruleus, while Aquila fasciata, Falco chicquera and Nisaetus cirrhatus show a higher proportion of birds. Species with greatest similarity of diet were C. gallicus and S. cheela. Considering the environmental characterization of areas where raptors built the nest, some species were ecologically closer than others. N. cirrhatus and S. cheela were related to the presence of water bodies, dry deciduous forest and evergreen forests, while E. caeruleus and C. gallicus preferred more open habitats. A. fasciata bred either on cliffs or trees, F. chicquera on trees or mobile towers, and the other four species built their nests exclusively in trees.Conclusions: We conclude that although there was overlap in diet and nesting ecology for a number of species, the geographical separation likely limits competition for resources.
基金supported by Bintuan Science and Technology Program (2023AB078)Bintuan Agricultural Innovation Project (NCG202232)+2 种基金China Scholarship Council (NO.202208320271)Postgraduate Research&Practice Innovation Program of Jiangsu Province (KYCX22_3532,SJCX23_1991)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD),China.
文摘Dietary nutrient manipulation(e.g.protein fractions)could lower the environmental footprints of ruminants,especially reactive nitrogen(N).This study investigated the impacts of dietary soluble protein(SP)levels with decreased crude protein(CP)on intestinal N absorption,hindgut N metabolism,fecal microbiota and metabolites,and their linkage with N metabolism phenotype.Thirty-two male Hu sheep,with an age of six months and an initial BW of 40.37±1.18 kg,were randomly assigned to four dietary groups.The control diet(CON),aligning with NRC standards,maintained a CP content of 16.7%on a dry matter basis.Conversely,the experimental diets(LPA,LPB,and LPC)featured a 10%reduction in CP compared with CON,accompanied by SP adjustments to 21.2%,25.9%,and 29.4%of CP,respectively.Our results showed that low-protein diets led to significant reductions in the concentrations of plasma creatinine,ammonia,urea N,and fecal total short-chain fatty acids(SCFA)(P<0.05).Notably,LPB and LPC exhibited increased total SCFA and propionate concentrations compared with LPA(P<0.05).The enrichment of the Prevotella genus in fecal microbiota associated with energy metabolism and amino acid(AA)biosynthesis pathways was evident with SP levels in low-protein diets of approximately 25%to 30%.Moreover,LPB and LPC diets demonstrated a decrease in fecal NH_(4)^(+) eN and NO_(2) eN contents as well as urease activity,compared with CON(P<0.05).Concomitantly,reductions in fecal glutamic acid dehydrogenase gene(gdh),nitrite reductase gene(nirS),and nitric oxide reductase gene(norB)abundances were observed(P<0.05),pointing towards a potential reduction in reactive N production at the source.Of significance,the up-regulation of mRNA abundance of AA and peptide transporters in the small intestine(duodenum,jejunum,and ileum)and the elevated concentration of plasma AA(e.g.arginine,methionine,aspartate,glutamate,etc.)underscored the enhancement of N absorption and N efficiency.In summary,a 10%reduction in CP,coupled with an SP level of approximately 25%to 30%,demonstrated the potential to curtail reactive N emissions through fecal Prevotella enrichment and improve intestinal energy and N utilization efficiency.