Background Four-chambered stomach including the forestomachs(rumen,reticulum,and omasum)and abomasum allows ruminants convert plant fiber into high-quality animal products.The early development of this four-chambered ...Background Four-chambered stomach including the forestomachs(rumen,reticulum,and omasum)and abomasum allows ruminants convert plant fiber into high-quality animal products.The early development of this four-chambered stomach is crucial for the health and well-being of young ruminants,especially the immune development.However,the dynamics of immune development are poorly understood.Results We investigated the early gene expression patterns across the four-chambered stomach in Hu sheep,at 5,10,15,and 25 days of age.We found that forestomachs share similar gene expression patterns,all four stomachs underwent widespread activation of both innate and adaptive immune responses from d 5 to 25,whereas the metabolic function were significantly downregulated with age.We constructed a cell landscape of the four-chambered stomach using single-cell sequencing.Integrating transcriptomic and single-cell transcriptomic analyses revealed that the immune-associated module hub genes were highly expressed in T cells,monocytes and macrophages,as well as the defense-associated module hub genes were highly expressed in endothelial cells in the four-stomach tissues.Moreover,the non-immune cells such as epithelial cells play key roles in immune maturation.Cell communication analysis predicted that in addition to immune cells,non-immune cells recruit immune cells through macrophage migration inhibitory factor signaling in the forestomachs.Conclusions Our results demonstrate that the immune and defense responses of four stomachs are quickly developing with age in lamb's early life.We also identified the gene expression patterns and functional cells associated with immune development.Additionally,we identified some key receptors and signaling involved in immune regulation.These results help to understand the early life immune development at single-cell resolution,which has implications to develop nutritional manipulation and health management strategies based on specific targets including key receptors and signaling pathways.展开更多
Background:Diarrhea is a major cause of morbidity and mortality in young calves,resulting in considerable economic loss for dairy farms.To determine if some gut microbes might have resistance to dysbiotic process with...Background:Diarrhea is a major cause of morbidity and mortality in young calves,resulting in considerable economic loss for dairy farms.To determine if some gut microbes might have resistance to dysbiotic process with calf diarrhea by dictating the microbial co-occurrence patterns from birth to post-weaning,we examined the dynamic development of the gut microbiota and diarrhea status using two animal trials,with the first trial having 14 Holstein dairy calves whose fecal samples were collected 18 times over 78 d from birth to 15 d post-weaning and the second trial having 43 Holstein dairy calves whose fecal samples were collected daily from 8 to 18 days of age corresponding to the first diarrhea peak of trial 1.Results:Metataxonomic analysis of the fecal microbiota showed that the development of gut microbiota had three age periods with birth and weaning as the separatrices.Two diarrhea peaks were observed during the transition of the three age periods.Fusobacteriaceae was identified as a diarrhea-associated taxon both in the early stage and during weaning,and Clostridium_sensu_stricto_1 was another increased genus among diarrheic calves in the early stage.In the neonatal calves,Prevotella_2(ASV4 and ASV26),Prevotella_9(ASV43),and Alloprevotella(ASV14)were negatively associated with Clostridium_sensu_stricto_1(ASV48),the keystone taxa of the diarrhea-phase module.During weaning,unclassified Muribaculaceae(ASV28 and ASV44),UBA1819(ASV151),Barnesiella(ASV497),and Ruminococcaceae_UCG-005(ASV254)were identified being associated with non-diarrheic status,and they aggregated in the non-diarrhea module of co-occurrence patterns wherein unclassified Muribaculaceae(ASV28)and Barnesiella(ASV497)had a direct negative relationship with the members of the diarrhea module.Conclusions:Taken together,our results suggest that the dynamic successions of calf gut microbiota and the interactions among some bacteria could influence calf diarrhea,and some species of Prevotella might be the core microbiota in both neonatal and weaning calves,while species of Muribaculaceae might be the core microbiota in weaning calves for preventing calf diarrhea.Some ASVs affiliated with Prevotella_2(ASV4 and ASV26),Prevotella_9(ASV43),Alloprevotella(AVS14),unclassified Muribaculaceae(ASV28 and ASV44),UBA1819(ASV151),Ruminococcaceae_UCG-005(ASV254),and Barnesiella(ASV497)might be proper probiotics for preventing calf diarrhea whereas Clostridium_sensu_stricto_1(ASV48)might be the biomarker for diarrhea risk in specific commercial farms.展开更多
Background： A possible option to meet the increased demand of forage for dairy industry is to use the agricultural byproducts, such as corn stover. However, nutritional value of crop residues is low and we have been ...Background： A possible option to meet the increased demand of forage for dairy industry is to use the agricultural byproducts, such as corn stover. However, nutritional value of crop residues is low and we have been seeking technologies to improve the value. A feeding trial was performed to evaluate the effects of four levels of Saccharomyces cerevisiae fermentation product（SCFP; Original XP; Diamond V） on lactation performance and rumen fermentation in mid-lactation Holstein dairy cows fed a diet containing low-quality forage. Eighty dairy cows were randomly assigned into one of four treatments： basal diet supplemented with 0, 60, 120, or 180 g/d of SCFP per head mixed with 180, 120, 60, or 0 g of corn meal, respectively. The experiment lasted for 10 wks, with the first 2 weeks for adaptation.Results： Dry matter intake was found to be similar（P 〉 0.05） among the treatments. There was an increasing trend in milk production（linear, P ≤ 0.10） with the increasing level of SCFP supplementation, with no effects on contents of milk components（P 〉 0.05）. Supplementation of SCFP linearly increased（P 〈 0.05） the N conversion, without affecting rumen pH and ammonia-N（P 〉 0.05）. Increasing level of SCFP linearly increased（P 〈 0.05） concentrations of ruminal total volatile fatty acids, acetate, propionate, and butyrate, with no difference in molar proportion of individual acids（P 〉 0.05）. The population of fungi and certain cel ulolytic bacteria（Ruminococcus albus, R. flavefaciens and Fibrobacter succinogenes）increased linearly（P 〈 0.05） but those of lactate-utilizing（Selenomonas ruminantium and Megasphaera elsdeni） and lactate-producing bacteria（Streptococcus bovis） decreased linearly（P ≤ 0.01） with increasing level of SCFP. The urinary purine derivatives increased linearly（P 〈 0.05） in response to SCFP supplementation, indicating that SCFP supplementation may benefit for microbial protein synthesis in the rumen.Conclusions： The SCFP supplementation was effective in maintaining milk persistency of mid-lactation cows receiving diets containing low-quality forage. The beneficial effect of SCFP could be attributed to improved rumen function; 1）microbial population shift toward greater rumen fermentation efficiency indicated by higher rumen fungi and cel ulolytic bacteria and lower lactate producing bacteria, and 2） rumen microbial fermentation toward greater supply of energy and protein indicated by greater ruminal VFA concentration and increased N conversion. Effects of SCFP were dose-depended and greater effects being observed with higher levels of supplementation and the effect was more noticeable during the high THI environment.展开更多
Background： Alfalfa hay and corn stover are different type of forages which can significantly impact a cow＇s lactation performance, but the underlying metabolic mechanism has been poorly studied. We used biomarker a...Background： Alfalfa hay and corn stover are different type of forages which can significantly impact a cow＇s lactation performance, but the underlying metabolic mechanism has been poorly studied. We used biomarker and pathway analyses to characterize related biomarkers and pathways based on urine metabolomics data from different forage treatments. Urine was col ected from 16 multiparous Holstein dairy cows fed alfalfa hay（AH, high-quality forage, n = 8） and corn stover（CS, low-quality forage, n = 8） respectively. Gas chromatography–time of flight/mass spectrometry（GC-TOF/MS） was performed to identify metabolites in urine and the metaboanalyst online platform was used to do biomarker and pathway analysis.Results： Hippuric acid（HUA） and N-methyl-glutamic（NML-Glu） indicated the most significant difference between the two diets, when statistical y validated by biomarker analysis. HUA was also validated by standard compound quantitative method and showed significant higher concentration in CS group than AH group（2.8282 vs. 0.0005 mg/mL; P 〈 0.01）.The significant negative correlation between milk yield and HUA（R^2= 0.459; P 〈 0.01） and significant positive correlation between milk yield and NML-Glu（R^2= 0.652; P 〈 0.01） were characterized. The pathway analysis revealed that these different metabolites were involved in 17 pathways including 7 influential pathways（pathway impact value 〉 0）： Tyr metabolism, starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, galactose metabolism,Phe, Tyr and Try biosynthesis, purine metabolism, and glycerolipid metabolism. Based on the metabolome view map,the Phe, Tyr and Try biosynthesis pathway exhibited the highest impact value（0.50）, and the Holm-Bonferroni multiple testing-based analysis revealed the most significant difference in the Tyr metabolism pathway（Holm P = 0.048）.Conclusions： The identified HUA and NML-Glu may serve as potential biomarkers for discriminating CS and AH diets and could be used as candidates for milk yield related mechanistic investigations. Integrated network pathways associated with related metabolites provide a helpful perspective for discovering the effectiveness of forage quality in lactation performance and provides novel insights into developing strategies for better utilization of CS and other low-quality forage in China.展开更多
Background： Fat is the primary source of the volatiles that determine the characteristic flavors of animal products.Because unsaturated fatty acids（UFAs） contribute to changes in flavor as a result of the oxidation...Background： Fat is the primary source of the volatiles that determine the characteristic flavors of animal products.Because unsaturated fatty acids（UFAs） contribute to changes in flavor as a result of the oxidation process, a feeding trial was performed to investigate the effects of dietary soybean oil or antioxidants on the fatty acid and volatile profiles of the tail subcutaneous（SF） and perirenal fat tissues（PF） of fattening lambs. Thirty-six Huzhou lambs were assigned to four dietary treatments in a randomized block design. The lambs＇ diets were supplemented with soybean oil（0 or 3 % of DM） or antioxidants（0 or 0.025 % of DM）.Results： Neither soybean oil nor antioxidant supplementation had an effect on lamb growth（P 〉 0.05）. In regard to tail SF, soybean oil supplementation increased the 18：2n6t（P 〈 0.05） and the total amount of volatile acids,whereas antioxidant supplementation increased the content of C18：2n6c and C18：3n3（P 〈 0.05） but had no effect on the volatiles profile. In regard to PF, dietary soybean oil supplementation increased the C18：0 content（P 〈 0.01）;decreased the C18：1（P = 0.01）, C22：1 n9（P 〈 0.01） and total UFA（P = 0.03） contents; and tended to decrease the E-2-octenal（P = 0.08）, E, E-2, 4-decadienal（P = 0.10）, 2-undecenal（P = 0.14） and ethyl 9-decenoate（P = 0.10） contents.Antioxidant supplementation did not affect either the fatty acid content or the volatiles profile in the PF.Conclusions： Tail SF and PF responded to dietary soybean oil and antioxidant supplementation in different ways. For SF, both soybean oil and antioxidant supplementation increased the levels of unsaturated fatty acids but triggered only a slight change in volatiles. For PF, soybean oil supplementation decreased the levels of unsaturated fatty acids and oxidative volatiles, but supplementation with antioxidants had little effect on PF fatty acids and the volatiles profile.展开更多
Improving feed efficiency is crucial to the animal industry.Residual feed intake(RFI)is now regarded as an index of feed efficiency evaluation and is independent of growth characteristics.Our study aims to explore the...Improving feed efficiency is crucial to the animal industry.Residual feed intake(RFI)is now regarded as an index of feed efficiency evaluation and is independent of growth characteristics.Our study aims to explore the alterations in growth performance and nutrient digestion in Hu sheep with different RFI phenotypes.Sixty-four male Hu sheep(body weight=24.39±1.12 kg;postnatal days=90±7.9)were selected for the study.After an evaluation period of 56 days and power analysis,samples were collected from 14 low RFI(L-RFI group,power=0.95)and 14 high RFI sheep(H-RFI group,power=0.95).The L-RFI sheep yielded a lower(P<0.05)feed conversion ratio and dry matter intake;however,both groups exhibited similar average daily gain(P>0.05).The acid detergent fiber,neutral detergent fiber,organic matter,and crude protein apparent digestibility were higher(P<0.05)in L-RFI sheep.N intake and fecal N output(%of N intake)were lower(P<0.05)and N retention(%of N intake)was higher(P<0.05)in L-RFI sheep,whereas no difference(P>0.05)was found in urine N output(%of N intake)between the 2 groups.Furthermore,L-RFI sheep gave lower(P<0.05)serum glucose concentrations and higher(P<0.05)non-esterified fatty acid concentrations.Meanwhile,a lower ruminal acetate molar proportion(P<0.05)and higher propionate molar proportion(P<0.05)were observed in L-RFI sheep.In summary,these results revealed that despite having lower dry matter intake,L-RFI sheep possess higher nutrient digestibility,N retention,ruminal propionate production and serum glucose utilization,in order to meet energy demands.Selection for low RFI sheep could reduce feed costs,which in turn provides economic benefits to the sheep industry.展开更多
Eco-friendly and efficient strategies for eliminating cadmium (Cd) phytoremediation plant residues are needed. The present study investigated the feasibility of feeding Cd accumulator maize to beef cattle. In total, 2...Eco-friendly and efficient strategies for eliminating cadmium (Cd) phytoremediation plant residues are needed. The present study investigated the feasibility of feeding Cd accumulator maize to beef cattle. In total, 20 cattle at 6 months of age were selected and randomly allocated into two groups fed with 85.82%(fresh basis) Cd accumulator maize (CAM) or normal maize (control [Con]) silage diets for 107 d. Feeding CAM did not affect the body weight (P=0.24), while it decreased feed intake and increased feed efficiency of beef cattle (P <0.01). Feeding CAM increased serum concentrations of immunoglobulin A and G, complement 3 and 4, blood urea nitrogen, and low-density lipoprotein cholesterol, decreased serum concentrations of interleukin-6 and lipopolysaccharide (P <0.05), and caused wider lumens in the renal tubules. The Cd residue in meat was 7μg/kg beyond the restriction for human food. In the muscle, the unsaturated fatty acids (t11C18:1 and C20:4), Lys, Arg, Pro, and Cys were decreased, while the saturated fatty acids (C10:0, C12:0, and C17:0) and Leu were increased (P <0.05). Therefore, at the current feeding level, phytoremediation maize increased the feed efficiency of beef cattle, but did present risks to cattle health and production safety, and decreased the meat nutrition and flavor. Further research must be performed to determine whether a lower proper dose of phytoremediation maize and an appropriate feeding period may be possible to ensure no risk to cattle health and the supply of safe meat for humans.展开更多
基金partially supported by the Natural Science Foundation of Zhejiang Province(Award number:D21C170001)the National Natural Science Foundation of China(Award number:31973000)。
文摘Background Four-chambered stomach including the forestomachs(rumen,reticulum,and omasum)and abomasum allows ruminants convert plant fiber into high-quality animal products.The early development of this four-chambered stomach is crucial for the health and well-being of young ruminants,especially the immune development.However,the dynamics of immune development are poorly understood.Results We investigated the early gene expression patterns across the four-chambered stomach in Hu sheep,at 5,10,15,and 25 days of age.We found that forestomachs share similar gene expression patterns,all four stomachs underwent widespread activation of both innate and adaptive immune responses from d 5 to 25,whereas the metabolic function were significantly downregulated with age.We constructed a cell landscape of the four-chambered stomach using single-cell sequencing.Integrating transcriptomic and single-cell transcriptomic analyses revealed that the immune-associated module hub genes were highly expressed in T cells,monocytes and macrophages,as well as the defense-associated module hub genes were highly expressed in endothelial cells in the four-stomach tissues.Moreover,the non-immune cells such as epithelial cells play key roles in immune maturation.Cell communication analysis predicted that in addition to immune cells,non-immune cells recruit immune cells through macrophage migration inhibitory factor signaling in the forestomachs.Conclusions Our results demonstrate that the immune and defense responses of four stomachs are quickly developing with age in lamb's early life.We also identified the gene expression patterns and functional cells associated with immune development.Additionally,we identified some key receptors and signaling involved in immune regulation.These results help to understand the early life immune development at single-cell resolution,which has implications to develop nutritional manipulation and health management strategies based on specific targets including key receptors and signaling pathways.
基金the National Key Research and Development Program of China(2017YFD0500502)。
文摘Background:Diarrhea is a major cause of morbidity and mortality in young calves,resulting in considerable economic loss for dairy farms.To determine if some gut microbes might have resistance to dysbiotic process with calf diarrhea by dictating the microbial co-occurrence patterns from birth to post-weaning,we examined the dynamic development of the gut microbiota and diarrhea status using two animal trials,with the first trial having 14 Holstein dairy calves whose fecal samples were collected 18 times over 78 d from birth to 15 d post-weaning and the second trial having 43 Holstein dairy calves whose fecal samples were collected daily from 8 to 18 days of age corresponding to the first diarrhea peak of trial 1.Results:Metataxonomic analysis of the fecal microbiota showed that the development of gut microbiota had three age periods with birth and weaning as the separatrices.Two diarrhea peaks were observed during the transition of the three age periods.Fusobacteriaceae was identified as a diarrhea-associated taxon both in the early stage and during weaning,and Clostridium_sensu_stricto_1 was another increased genus among diarrheic calves in the early stage.In the neonatal calves,Prevotella_2(ASV4 and ASV26),Prevotella_9(ASV43),and Alloprevotella(ASV14)were negatively associated with Clostridium_sensu_stricto_1(ASV48),the keystone taxa of the diarrhea-phase module.During weaning,unclassified Muribaculaceae(ASV28 and ASV44),UBA1819(ASV151),Barnesiella(ASV497),and Ruminococcaceae_UCG-005(ASV254)were identified being associated with non-diarrheic status,and they aggregated in the non-diarrhea module of co-occurrence patterns wherein unclassified Muribaculaceae(ASV28)and Barnesiella(ASV497)had a direct negative relationship with the members of the diarrhea module.Conclusions:Taken together,our results suggest that the dynamic successions of calf gut microbiota and the interactions among some bacteria could influence calf diarrhea,and some species of Prevotella might be the core microbiota in both neonatal and weaning calves,while species of Muribaculaceae might be the core microbiota in weaning calves for preventing calf diarrhea.Some ASVs affiliated with Prevotella_2(ASV4 and ASV26),Prevotella_9(ASV43),Alloprevotella(AVS14),unclassified Muribaculaceae(ASV28 and ASV44),UBA1819(ASV151),Ruminococcaceae_UCG-005(ASV254),and Barnesiella(ASV497)might be proper probiotics for preventing calf diarrhea whereas Clostridium_sensu_stricto_1(ASV48)might be the biomarker for diarrhea risk in specific commercial farms.
基金supported by funds from Diamond V(Cedar Rapids,IA)the China Agriculture(Dairy Cow)Research System(CARS-37)
文摘Background： A possible option to meet the increased demand of forage for dairy industry is to use the agricultural byproducts, such as corn stover. However, nutritional value of crop residues is low and we have been seeking technologies to improve the value. A feeding trial was performed to evaluate the effects of four levels of Saccharomyces cerevisiae fermentation product（SCFP; Original XP; Diamond V） on lactation performance and rumen fermentation in mid-lactation Holstein dairy cows fed a diet containing low-quality forage. Eighty dairy cows were randomly assigned into one of four treatments： basal diet supplemented with 0, 60, 120, or 180 g/d of SCFP per head mixed with 180, 120, 60, or 0 g of corn meal, respectively. The experiment lasted for 10 wks, with the first 2 weeks for adaptation.Results： Dry matter intake was found to be similar（P 〉 0.05） among the treatments. There was an increasing trend in milk production（linear, P ≤ 0.10） with the increasing level of SCFP supplementation, with no effects on contents of milk components（P 〉 0.05）. Supplementation of SCFP linearly increased（P 〈 0.05） the N conversion, without affecting rumen pH and ammonia-N（P 〉 0.05）. Increasing level of SCFP linearly increased（P 〈 0.05） concentrations of ruminal total volatile fatty acids, acetate, propionate, and butyrate, with no difference in molar proportion of individual acids（P 〉 0.05）. The population of fungi and certain cel ulolytic bacteria（Ruminococcus albus, R. flavefaciens and Fibrobacter succinogenes）increased linearly（P 〈 0.05） but those of lactate-utilizing（Selenomonas ruminantium and Megasphaera elsdeni） and lactate-producing bacteria（Streptococcus bovis） decreased linearly（P ≤ 0.01） with increasing level of SCFP. The urinary purine derivatives increased linearly（P 〈 0.05） in response to SCFP supplementation, indicating that SCFP supplementation may benefit for microbial protein synthesis in the rumen.Conclusions： The SCFP supplementation was effective in maintaining milk persistency of mid-lactation cows receiving diets containing low-quality forage. The beneficial effect of SCFP could be attributed to improved rumen function; 1）microbial population shift toward greater rumen fermentation efficiency indicated by higher rumen fungi and cel ulolytic bacteria and lower lactate producing bacteria, and 2） rumen microbial fermentation toward greater supply of energy and protein indicated by greater ruminal VFA concentration and increased N conversion. Effects of SCFP were dose-depended and greater effects being observed with higher levels of supplementation and the effect was more noticeable during the high THI environment.
基金supported by grants from the National Natural Science Foundation of China(No.31472121)from the China Agriculture Research System(No.CARS-37)The funding body has not participated in or interfered with the research
文摘Background： Alfalfa hay and corn stover are different type of forages which can significantly impact a cow＇s lactation performance, but the underlying metabolic mechanism has been poorly studied. We used biomarker and pathway analyses to characterize related biomarkers and pathways based on urine metabolomics data from different forage treatments. Urine was col ected from 16 multiparous Holstein dairy cows fed alfalfa hay（AH, high-quality forage, n = 8） and corn stover（CS, low-quality forage, n = 8） respectively. Gas chromatography–time of flight/mass spectrometry（GC-TOF/MS） was performed to identify metabolites in urine and the metaboanalyst online platform was used to do biomarker and pathway analysis.Results： Hippuric acid（HUA） and N-methyl-glutamic（NML-Glu） indicated the most significant difference between the two diets, when statistical y validated by biomarker analysis. HUA was also validated by standard compound quantitative method and showed significant higher concentration in CS group than AH group（2.8282 vs. 0.0005 mg/mL; P 〈 0.01）.The significant negative correlation between milk yield and HUA（R^2= 0.459; P 〈 0.01） and significant positive correlation between milk yield and NML-Glu（R^2= 0.652; P 〈 0.01） were characterized. The pathway analysis revealed that these different metabolites were involved in 17 pathways including 7 influential pathways（pathway impact value 〉 0）： Tyr metabolism, starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, galactose metabolism,Phe, Tyr and Try biosynthesis, purine metabolism, and glycerolipid metabolism. Based on the metabolome view map,the Phe, Tyr and Try biosynthesis pathway exhibited the highest impact value（0.50）, and the Holm-Bonferroni multiple testing-based analysis revealed the most significant difference in the Tyr metabolism pathway（Holm P = 0.048）.Conclusions： The identified HUA and NML-Glu may serve as potential biomarkers for discriminating CS and AH diets and could be used as candidates for milk yield related mechanistic investigations. Integrated network pathways associated with related metabolites provide a helpful perspective for discovering the effectiveness of forage quality in lactation performance and provides novel insights into developing strategies for better utilization of CS and other low-quality forage in China.
基金financed by the Innovation Team Program of Zhejiang province(2011R50025)
文摘Background： Fat is the primary source of the volatiles that determine the characteristic flavors of animal products.Because unsaturated fatty acids（UFAs） contribute to changes in flavor as a result of the oxidation process, a feeding trial was performed to investigate the effects of dietary soybean oil or antioxidants on the fatty acid and volatile profiles of the tail subcutaneous（SF） and perirenal fat tissues（PF） of fattening lambs. Thirty-six Huzhou lambs were assigned to four dietary treatments in a randomized block design. The lambs＇ diets were supplemented with soybean oil（0 or 3 % of DM） or antioxidants（0 or 0.025 % of DM）.Results： Neither soybean oil nor antioxidant supplementation had an effect on lamb growth（P 〉 0.05）. In regard to tail SF, soybean oil supplementation increased the 18：2n6t（P 〈 0.05） and the total amount of volatile acids,whereas antioxidant supplementation increased the content of C18：2n6c and C18：3n3（P 〈 0.05） but had no effect on the volatiles profile. In regard to PF, dietary soybean oil supplementation increased the C18：0 content（P 〈 0.01）;decreased the C18：1（P = 0.01）, C22：1 n9（P 〈 0.01） and total UFA（P = 0.03） contents; and tended to decrease the E-2-octenal（P = 0.08）, E, E-2, 4-decadienal（P = 0.10）, 2-undecenal（P = 0.14） and ethyl 9-decenoate（P = 0.10） contents.Antioxidant supplementation did not affect either the fatty acid content or the volatiles profile in the PF.Conclusions： Tail SF and PF responded to dietary soybean oil and antioxidant supplementation in different ways. For SF, both soybean oil and antioxidant supplementation increased the levels of unsaturated fatty acids but triggered only a slight change in volatiles. For PF, soybean oil supplementation decreased the levels of unsaturated fatty acids and oxidative volatiles, but supplementation with antioxidants had little effect on PF fatty acids and the volatiles profile.
基金supported by grants from the National Natural Science Foundation of China(31973000)National Key Research and Development Program of China(2018YFD0501903).
文摘Improving feed efficiency is crucial to the animal industry.Residual feed intake(RFI)is now regarded as an index of feed efficiency evaluation and is independent of growth characteristics.Our study aims to explore the alterations in growth performance and nutrient digestion in Hu sheep with different RFI phenotypes.Sixty-four male Hu sheep(body weight=24.39±1.12 kg;postnatal days=90±7.9)were selected for the study.After an evaluation period of 56 days and power analysis,samples were collected from 14 low RFI(L-RFI group,power=0.95)and 14 high RFI sheep(H-RFI group,power=0.95).The L-RFI sheep yielded a lower(P<0.05)feed conversion ratio and dry matter intake;however,both groups exhibited similar average daily gain(P>0.05).The acid detergent fiber,neutral detergent fiber,organic matter,and crude protein apparent digestibility were higher(P<0.05)in L-RFI sheep.N intake and fecal N output(%of N intake)were lower(P<0.05)and N retention(%of N intake)was higher(P<0.05)in L-RFI sheep,whereas no difference(P>0.05)was found in urine N output(%of N intake)between the 2 groups.Furthermore,L-RFI sheep gave lower(P<0.05)serum glucose concentrations and higher(P<0.05)non-esterified fatty acid concentrations.Meanwhile,a lower ruminal acetate molar proportion(P<0.05)and higher propionate molar proportion(P<0.05)were observed in L-RFI sheep.In summary,these results revealed that despite having lower dry matter intake,L-RFI sheep possess higher nutrient digestibility,N retention,ruminal propionate production and serum glucose utilization,in order to meet energy demands.Selection for low RFI sheep could reduce feed costs,which in turn provides economic benefits to the sheep industry.
基金supported by the Department of Agriculture and Rural Affairs of Hunan Province,the Construction of Modern Agricultural Industrial Technology System in Hunan Province(Hunan Financial Agriculture Guide 2019[97]).
文摘Eco-friendly and efficient strategies for eliminating cadmium (Cd) phytoremediation plant residues are needed. The present study investigated the feasibility of feeding Cd accumulator maize to beef cattle. In total, 20 cattle at 6 months of age were selected and randomly allocated into two groups fed with 85.82%(fresh basis) Cd accumulator maize (CAM) or normal maize (control [Con]) silage diets for 107 d. Feeding CAM did not affect the body weight (P=0.24), while it decreased feed intake and increased feed efficiency of beef cattle (P <0.01). Feeding CAM increased serum concentrations of immunoglobulin A and G, complement 3 and 4, blood urea nitrogen, and low-density lipoprotein cholesterol, decreased serum concentrations of interleukin-6 and lipopolysaccharide (P <0.05), and caused wider lumens in the renal tubules. The Cd residue in meat was 7μg/kg beyond the restriction for human food. In the muscle, the unsaturated fatty acids (t11C18:1 and C20:4), Lys, Arg, Pro, and Cys were decreased, while the saturated fatty acids (C10:0, C12:0, and C17:0) and Leu were increased (P <0.05). Therefore, at the current feeding level, phytoremediation maize increased the feed efficiency of beef cattle, but did present risks to cattle health and production safety, and decreased the meat nutrition and flavor. Further research must be performed to determine whether a lower proper dose of phytoremediation maize and an appropriate feeding period may be possible to ensure no risk to cattle health and the supply of safe meat for humans.
