Background During the transition period,cows are prone to negative energy balance,which can lead to a decline in production performance and health in severe cases.In recent years,it has been discovered that bile acids...Background During the transition period,cows are prone to negative energy balance,which can lead to a decline in production performance and health in severe cases.In recent years,it has been discovered that bile acids(BAs)can act not only as fat emulsifiers but also as signaling molecules to regulate body metabolism.Although BAs have been used to some extent in monogastric and aquatic animals,their role in ruminants,particularly in transition cows,remains unclear.Therefore,this study aimed to determine the effects of BAs on the production performance,milk and plasma fatty acid and BA composition,and fecal microbiota in transition dairy cows.Results Forty-six healthy transition Holstein dairy cows with similar conditions were randomly divided into two groups and supplemented with 0 or 20 g/d of BAs from 21 d before the expected calving to 21 d after calving.The production performance was tracked until 60 d after calving.The results indicated that BA supplementation significantly improved postpartum milk fat content and yields as well as the yields of unsaturated fatty acids,monounsaturated fatty acids,and polyunsaturated fatty acids in milk.There was a significant increase in the concentration of triglyceride and the proportion of C≤16 fatty acids in the plasma of cows supplemented with BAs,while the concentration of β-hydroxybutyrate and the proportion of C>16 fatty acids in the plasma decreased significantly.BA supplementation significantly altered the composition of the fecal bacterial community and increased the relative abundance of bacteria beneficial for BA metabolism and transformation(Romboutsia,Clostridium sensu_stricto_6,and Clostridium sensu_stricto_1).Functional prediction analysis showed that the relative abundance of bile salt hydrolase,7 α-hydroxysteroid dehydrogenase,and BA inducible E as well as the pathways related to BA metabolism also significantly increased in cows supplemented BAs.In addition,BA supplementation significantly altered the composition of plasma and fecal BAs,particularly increasing circulating secondary BA concentration,which might induce the complete oxidation of fatty acids in the liver and further reduce the concentration of β-hydroxybutyrate.Conclusions These findings highlight the potential benefits of BA supplementation in improving milk yields and quality,as well as influencing metabolic pathways in transition dairy cows.Meanwhile,further studies are needed to elucidate the underlying mechanisms and explore the broader implications of these results by using more tissue samples.展开更多
The objective of this study was to analyze the dynamics of nutrient balance,physiological biomarkers and comprehensive indexes associated with metabolism and function of organs in transition cows.Fourteen transition c...The objective of this study was to analyze the dynamics of nutrient balance,physiological biomarkers and comprehensive indexes associated with metabolism and function of organs in transition cows.Fourteen transition cows were used for this research.Dietary intake was recorded daily,and samples of the diet,venous blood and milk were collected for measurements.The balance values of net energy for lactation(NEL),metabolizable protein(MP),and metabolizable glucose(MG) were calculated,and regression analysis and calculation of comprehensive indexes were performed.Accordingly,the prepartum cows presented positive balances of NEL,MP,and MG,while severe negative balances were found during the postpartum period.Dynamic changes of energy metabolism,nutrient mobilization,liver function,anti-oxidative status and immune response,as indicated by blood biomarkers and modified comprehensive indexes,were out of sync with the calculated balance values,but they were closely related to the day relative to calving.Compared with the 21 d prepartum,the plasma concentrations of non-esterified fatty acids(NEFA) and β-hydroxybutyric acid(BHBA) were significantly increased around and after calving(P<0.05),and similar variation tendency was observed for most of other parameters.The occurrence of parturition and the initiation of lactation were more responsible for the negative balances of nutrients in transition dairy cows.Although negative balances of NEL,MP and MG were not observed using the assessment model,the nutritional strategies should be applied before calving,because metabolic adaptations had been validated during the prepartum period.In addition,it was plausible to conclude that the decline of hepatic metabolism,defense function and insulin sensitivity are critical causes of metabolic dysfunction.展开更多
Background： Failure to expel fetal membranes within 24 h of calving is a pathological condition defined as retained placenta（RP）. The objective of this investigation was to evaluate whether there are alterations in...Background： Failure to expel fetal membranes within 24 h of calving is a pathological condition defined as retained placenta（RP）. The objective of this investigation was to evaluate whether there are alterations in several selected serum variables related to innate immunity and carbohydrate and lipid metabolism that precede occurrence of RP in transition Holstein dairy cows.Methods： One hundred multiparous Holstein dairy cows were involved in the study. Blood samples were collected from the coccygeal vein during the-8 to ＋4 wks around parturition, once per week before the morning feeding.Six healthy control cows（CON） and 6 cows with RP were selected and serum samples at-8,-4, time of diagnosis of disease, and ＋4 wks relative to parturition were used for analyses. All samples were analyzed for lactate, nonesterified fatty acids（NEFA）, β-hydroxybutyrate（BHBA）, interleukin-1（IL-1）, interleukin-6（IL-6）, tumor necrosis factor（TNF）, haptoglobin（Hp）, and serum amyloid A（SAA）.Results： Cows with RP had greater concentrations of serum lactate, IL-1, IL-6, TNF, and SAA in comparison with CON cows. Intriguingly, elevated concentrations of all five variables were observed at-8 and-4 wks before the occurrence of RP compared to healthy cows. Cows with RP also had lower DMI and milk production vs CON animals; however milk composition was not affected by RP.Conclusions： Cows with RP showed an activated innate immunity 8 wks prior to diagnosis of disease. Overall results suggest that serum IL-1, IL- 6, and TNF, and lactate can be used as screening biomarkers to indicate cows that might have health issues during the transition period.展开更多
The objective of this study was to evaluate the effects of vitamin E（VE; 1 500 or 3 000 international units（IU） d^（-1）） and fat（2% of dry matter calcium salt of soybean oil） supplementation during the transiti...The objective of this study was to evaluate the effects of vitamin E（VE; 1 500 or 3 000 international units（IU） d^（-1）） and fat（2% of dry matter calcium salt of soybean oil） supplementation during the transition period on feed intake, milk yield and composition and blood metabolites of dairy cows. 48 multiparous Holstein cows were randomly assigned into one of four treatments in a 2×2 factorial arrangement of vitamin E and supplemental dietary fat during the transition period. Treatments were： 1） 1 500 IU d^（-1） vitamin E without fat supplementation（1 500VE-F）; 2） 1 500 IU d^（-1） vitamin E with fat supplement（1 500VE＋F）; 3） 3 000 IU d^（-1） vitamin E without fat supplementation（3 000VE-F）; and 4） 3 000 IU d^（-1） vitamin E with fat supplement（3 000VE＋F）. Dietary treatments were initiated at approximately 28 d before expected calving dates and continued through 28 d postpartum. Dry matter intake（DMI） was unaffected（P〉0.05） by prepartum treatment. Regardless of vitamin E supplementation, DMI was greater（P〈0.01） in fat-supplemented cows compared with un-supplemented cows（19.60 vs. 18.45 kg d^（-1）; SEM=0.42） during the postpartum period. Energy balance and body weight were not affected（P〉0.05） by treatments. Postpartum diets had no significant effect on milk yield or milk composition. Plasma concentrations of non-esterified fatty acids, glucose, and insulin were not affected（P〉0.05） by treatments. Regardless of vitamin E supplementation, plasma β-hydroxybutyrate concentration was greater（P〈0.05） in fat-supplemented cows compared with un-supplemented cows during the postpartum period. These results showed no indication of positive effects on lactation performance associated with vitamin E and dietary fat supplement in transition cows.展开更多
Energy intake prepartum is critically important to health, milk performance, and profitability of dairy cows. The objective of this study was to determine the effect of reduced energy density of dose-up diets on dry m...Energy intake prepartum is critically important to health, milk performance, and profitability of dairy cows. The objective of this study was to determine the effect of reduced energy density of dose-up diets on dry matter intake （DMI）, lactation performance and energy balance （EB） in multiparous Holstein cows which were housed in a free-stall barn and fed for ad libitum intake. Thirty-nine dry cows were blocked and assigned randomly to three groups fed a high energy density diet [HD, n = 13; 6.8 MJ of net energy for lactation （NEL）/kg; 14.0% crude protein （CP） ], or a middle energy density diet （MD, n = 13; 6.2 MJ NEh/kg; 14.0% CP）, or a low energy density diet （LD, n = 13; 5.4 MJ NEh/kg; 14.0% CP） from d 21 before expected day of calving. After parturition, all cows were fed the same lactation diet to d 70 in milk （DIM）. The DMI and NEE intake prepartum were decreased by the reduced energy density diets （P 〈 0.05）. The LD group consumed 1.3 last 24 h before calving. The milk yield and the postpartum kg/d （DM） more diet compared with HD group in the DMI were increased by the reduced energy density diet prepartum （P 〈 0.05）. The changes in BCS and BW prepartum and postpartum were not affected by prepartum diets HD group had higher milk fat content and lower lactose content compared with LD group during the first 3 wk of lactation （P 〈 0.05）. The energy consumption for HD, MD and LD groups were 149.8%, 126.2% and 101.1 % of their calculated energy requirements prepartum （P 〈 0.05）, and 72.7%, 73.1% and 7.5.2% during the first 4 wk postpartum, respectively. In conclusion, the low energy density prepartum diet was effective in controlling NF_L intake prepartum, and was beneficial in increasing DMI and milk yield, and alleviating negative EB postpartum.展开更多
Background： G-protein coupled receptors（GPCR）, also referred as Free Fatty Acid Receptors（FFAR）, are widely studied within human medicine as drug targets for metabolic disorders. To combat metabolic disorders pre...Background： G-protein coupled receptors（GPCR）, also referred as Free Fatty Acid Receptors（FFAR）, are widely studied within human medicine as drug targets for metabolic disorders. To combat metabolic disorders prevalent in dairy cows during the transition period, which co-occur with negative energy balance and changes to lipid and glucose metabolism, it may be helpful to identify locations and roles of FFAR and other members of the GPCR family in bovine tissues.Results： Quantitative RT-PCR（qPCR） of subcutaneous adipose, liver, and PMNL samples during the transition period（-10, ＋7, and ＋20 or ＋30 d） were used for expression profiling of medium-（MCFA） and long-chain fatty acid（LCFA）receptors GPR120 and GPR40, MCFA receptor GPR84, and niacin receptor HCAR2/3. Adipose samples were obtained from cows with either high（HI; BCS ≥ 3.75） or low（LO; BCS ≤ 3.25） body condition score（BCS） to examine whether FFAR expression is correlated with this indicator of health and body reserves. Supplementation of rumen-protected methionine（MET）, which may improve immune function and production postpartum, was also compared with unsupplemented control（CON） cows for liver and blood polymorphonuclear leukocytes（PMNL） samples. In adipose tissue, GPR84 and GPR120 were differentially expressed over time, while GPR40 was not expressed; in PMNL, GPR40 was differentially expressed over time and between MET vs. CON, GPR84 expression differed only between dietary groups, and GPR120 was not expressed; in liver, GPCR were either not expressed or barely detectable.Conclusions： The data indicate that there is likely not a direct role in liver for the selected GPCR during the transition period, but they do play variable roles in adipose and PMN. In future, these receptors may prove useful targets and/or markers for peripartal metabolism and immunity.展开更多
Background:Nutritional management in the dry period can alter body condition score(BCS)in dairy cows,a subjective measure of body fat.As such,differences in BCS during late-pregnancy not only mirror nutrient utilizati...Background:Nutritional management in the dry period can alter body condition score(BCS)in dairy cows,a subjective measure of body fat.As such,differences in BCS during late-pregnancy not only mirror nutrient utilization by fat depots,but also can play important roles on the metabolic and hormonal environment.We investigated the association between cow BCS during late-pregnancy on developmental parameters and blood variables of neonatal calves.Forty-nine multiparous Holstein cows were retrospectively divided by prepartal BCS into normal BCS≤3.25(NormBCS;3.02±0.17,n=30)or high BCS≥3.75(HighBCS;3.83±0.15,n=19)groups.Plasma samples were collected from cows at−10 d relative to parturition.Body weight,hip and wither height,hip width and body length were measured at birth and weekly through weaning(42 d of age)and until 9 weeks of age.Calf blood samples were collected from the jugular vein at birth(before receiving colostrum,0 d),24 h after first colostrum and at 7,21,42 and 50 d of age.The data were subjected to ANOVA using the mixed procedure of SAS.The statistical model included day,BCS,and their interactions.Results:Dry matter intake(kg/d or%of body weight)during the last 4 weeks of pregnancy was lower(P≤0.06)in HighBCS cows.Plasma concentrations of fatty acids,ceruloplasmin,and nitric oxide were greater overall(P<0.05)at d−10 prior to calving in HighBCS cows,and they tended(P=0.08)to have greater concentrations of reactive oxygen metabolites.Birth body weight was lower(P=0.03)in calves born to dams with HighBCS.In addition,plasma concentrations of fatty acids,albumin and urea(P<0.05)were greater in those calves.Although calves born to cows with HighBCS maintained a lower postnatal body weight(P=0.04),hip and wither height,hip width,and body length,there was no difference(P>0.05)in daily starter intake and average daily gain due to maternal BCS.Conclusions:Overall,results highlight an association between BCS during late-gestation on in utero calf development and postnatal growth.A high maternal BCS during late-gestation was associated with lower calf body weights,which could be due to lower maternal intakes and a state of inflammation and metabolic stress.展开更多
The objective of this study was to investigate the effects of supplementing N-carbamoylglutamate(NCG),an Arg enhancer,on amino acid(AA)supply and utilization and productive performance of early-lactating dairy cows.Th...The objective of this study was to investigate the effects of supplementing N-carbamoylglutamate(NCG),an Arg enhancer,on amino acid(AA)supply and utilization and productive performance of early-lactating dairy cows.Thirty multiparous Chinese Holstein dairy cows were randomly divided into con-trol(CON,n=15)and NCG(CON diet supplemented with NCG at 20 g/d per cow,n=15)groups at 4 wk before calving.Diets were offered individually in tie-stalls,and NCG was supplemented by top-dress feeding onto total mixed ration for the NCG group.The experiment lasted until wk 10 after calving.Dry matter intake tended to be higher(P=0.06),and yields of milk(P<0.01),milk protein(P<0.01),and milk fat(P<0.01)were higher in the NCG-cows than in the CON-cows.Plasma activities of aspartate aminotransferase(P<0.01),alanine aminotransferase(P=0.03),and plasma level ofβ-hydroxybutyrate(P=0.04)were lower in the NCG-cows than in the CON-cows,whereas plasma glucose(P=0.05)and nitric oxide(NO,P<0.01)concentrations were higher.Coccygeal vein concentrations of Cys(P<0.01),Pro(P<0.01),Tyr(P=0.05),most essential AA except Thr and His(P<0.01),total essential AA(P<0.01),and total AA(P<0.01)were higher in the NCG-cows than in the CON-cows.The arterial supply of all AA was greater in the NCG-cows than in the CON-cows.The NCG-cows had higher mammary plasma flow of AA(P=0.04)and clearance rate of Cys(P<0.01),Pro(P<0.01)and Asp(P<0.01),and higher ratios of uptake to output of Met(P=0.05),Lys(P<0.01),Cys(P=0.01),Pro(P=0.03),and Asp(P=0.01).In summary,addition of NCG initiated from the prepartum period improved the lactation performance of postpartum dairy cows,which might attribute to greater Arg and NO concentrations,as well as improved AA supply and utilization,liver function,and feed intake in these cows.展开更多
The objective of this study was to investigate whether supplementation with N-carbamoylglutamate(NCG)to cows during late gestation alters uteroplacental tissue nutrient transporters,calf metabolism and newborn weight....The objective of this study was to investigate whether supplementation with N-carbamoylglutamate(NCG)to cows during late gestation alters uteroplacental tissue nutrient transporters,calf metabolism and newborn weight.Thirty multiparous Chinese Holstein cows were used in a randomized complete block design experiment.During the last 28 d of pregnancy,cows were fed a diet without(CON)or with NCG(20 g/d per cow).The body weight of calves was weighed immediately after birth.Placentome samples were collected at parturition and used to assess mRNA expression of genes involved in transport of arginine,glucose,fatty acid and angiogenesis factors,as well as the mammalian target of rapamycin(mTOR)pathway.Blood samples of calves before colostrum consumption were also collected for the detection of plasma parameters,amino acids(AA)and metabolomics analysis.The newborn weight(P=0.02)and plasma Arg concentration of NCG-calves was significantly higher(P=0.05)than that of CON-calves,and the plasma concentrations of urea nitrogen tended to be lower(P=0.10)in the NCG group.The mRNA abundance of genes involved in glucose transport(solute carrier family 2 member 3[SLC2 A3],P<0.01),angiogenesis(nitric oxide synthase 3[NOS3],P=0.02),and mTOR pathway(serine/threonine-protein kinase 1[ACT1],P=0.10;euka ryotic translation initiation factor 4 B pseudogene 1[EIF4 BP1],P=0.08;EIF4 EBP2,P=0.04;and E74-like factor 2[ELF2],P=0.03)was upregulated in the placentome of NCG-supplemented cows.In addition,17 metabolites were significantly different in the placentome of NCG-supplemented cows compared to non-supplemented cows,and these metabolites are mainly involved in arginine and proline metabolism,alanine,aspartate and glutamate metabolism,and citrate cycle.In summary,the increased body weight of newborn calves from the NCG supplemented dairy cows maybe attributed to the increased angiogenesis and uteroplacental nutrient transport and to the activated mTOR signal pathway,which may result in the increased nutrient supply to the fetus,and improved AA metabolism and urea cycle of the fetus.展开更多
基金supported by the National Center of Technology Innovation for Dairy(No.2024-JSGG-021)the National Natural Science Foundation of China(No.32102570)the Key Research and Development Project of Ningxia(No.2024BBF01006).
文摘Background During the transition period,cows are prone to negative energy balance,which can lead to a decline in production performance and health in severe cases.In recent years,it has been discovered that bile acids(BAs)can act not only as fat emulsifiers but also as signaling molecules to regulate body metabolism.Although BAs have been used to some extent in monogastric and aquatic animals,their role in ruminants,particularly in transition cows,remains unclear.Therefore,this study aimed to determine the effects of BAs on the production performance,milk and plasma fatty acid and BA composition,and fecal microbiota in transition dairy cows.Results Forty-six healthy transition Holstein dairy cows with similar conditions were randomly divided into two groups and supplemented with 0 or 20 g/d of BAs from 21 d before the expected calving to 21 d after calving.The production performance was tracked until 60 d after calving.The results indicated that BA supplementation significantly improved postpartum milk fat content and yields as well as the yields of unsaturated fatty acids,monounsaturated fatty acids,and polyunsaturated fatty acids in milk.There was a significant increase in the concentration of triglyceride and the proportion of C≤16 fatty acids in the plasma of cows supplemented with BAs,while the concentration of β-hydroxybutyrate and the proportion of C>16 fatty acids in the plasma decreased significantly.BA supplementation significantly altered the composition of the fecal bacterial community and increased the relative abundance of bacteria beneficial for BA metabolism and transformation(Romboutsia,Clostridium sensu_stricto_6,and Clostridium sensu_stricto_1).Functional prediction analysis showed that the relative abundance of bile salt hydrolase,7 α-hydroxysteroid dehydrogenase,and BA inducible E as well as the pathways related to BA metabolism also significantly increased in cows supplemented BAs.In addition,BA supplementation significantly altered the composition of plasma and fecal BAs,particularly increasing circulating secondary BA concentration,which might induce the complete oxidation of fatty acids in the liver and further reduce the concentration of β-hydroxybutyrate.Conclusions These findings highlight the potential benefits of BA supplementation in improving milk yields and quality,as well as influencing metabolic pathways in transition dairy cows.Meanwhile,further studies are needed to elucidate the underlying mechanisms and explore the broader implications of these results by using more tissue samples.
基金supported by the National Key Research and Development Program of China (2017YFD0500500)the National Natural Science Foundation of China (31472122, 31672451)
文摘The objective of this study was to analyze the dynamics of nutrient balance,physiological biomarkers and comprehensive indexes associated with metabolism and function of organs in transition cows.Fourteen transition cows were used for this research.Dietary intake was recorded daily,and samples of the diet,venous blood and milk were collected for measurements.The balance values of net energy for lactation(NEL),metabolizable protein(MP),and metabolizable glucose(MG) were calculated,and regression analysis and calculation of comprehensive indexes were performed.Accordingly,the prepartum cows presented positive balances of NEL,MP,and MG,while severe negative balances were found during the postpartum period.Dynamic changes of energy metabolism,nutrient mobilization,liver function,anti-oxidative status and immune response,as indicated by blood biomarkers and modified comprehensive indexes,were out of sync with the calculated balance values,but they were closely related to the day relative to calving.Compared with the 21 d prepartum,the plasma concentrations of non-esterified fatty acids(NEFA) and β-hydroxybutyric acid(BHBA) were significantly increased around and after calving(P<0.05),and similar variation tendency was observed for most of other parameters.The occurrence of parturition and the initiation of lactation were more responsible for the negative balances of nutrients in transition dairy cows.Although negative balances of NEL,MP and MG were not observed using the assessment model,the nutritional strategies should be applied before calving,because metabolic adaptations had been validated during the prepartum period.In addition,it was plausible to conclude that the decline of hepatic metabolism,defense function and insulin sensitivity are critical causes of metabolic dysfunction.
基金Financial support for this project was provided by Genome Alberta(Calgary,Alberta,Canada)and National Science and Engineering Council of Canada(NSERC)to Dr.Ametaj as Principal Investigator
文摘Background： Failure to expel fetal membranes within 24 h of calving is a pathological condition defined as retained placenta（RP）. The objective of this investigation was to evaluate whether there are alterations in several selected serum variables related to innate immunity and carbohydrate and lipid metabolism that precede occurrence of RP in transition Holstein dairy cows.Methods： One hundred multiparous Holstein dairy cows were involved in the study. Blood samples were collected from the coccygeal vein during the-8 to ＋4 wks around parturition, once per week before the morning feeding.Six healthy control cows（CON） and 6 cows with RP were selected and serum samples at-8,-4, time of diagnosis of disease, and ＋4 wks relative to parturition were used for analyses. All samples were analyzed for lactate, nonesterified fatty acids（NEFA）, β-hydroxybutyrate（BHBA）, interleukin-1（IL-1）, interleukin-6（IL-6）, tumor necrosis factor（TNF）, haptoglobin（Hp）, and serum amyloid A（SAA）.Results： Cows with RP had greater concentrations of serum lactate, IL-1, IL-6, TNF, and SAA in comparison with CON cows. Intriguingly, elevated concentrations of all five variables were observed at-8 and-4 wks before the occurrence of RP compared to healthy cows. Cows with RP also had lower DMI and milk production vs CON animals; however milk composition was not affected by RP.Conclusions： Cows with RP showed an activated innate immunity 8 wks prior to diagnosis of disease. Overall results suggest that serum IL-1, IL- 6, and TNF, and lactate can be used as screening biomarkers to indicate cows that might have health issues during the transition period.
基金Isfahan University of Technology (IUT, Isfahan, Iran) for their financial support of this studythe personnel of Lavark Research Station (IUT) for their diligent animal care throughout the experiment
文摘The objective of this study was to evaluate the effects of vitamin E（VE; 1 500 or 3 000 international units（IU） d^（-1）） and fat（2% of dry matter calcium salt of soybean oil） supplementation during the transition period on feed intake, milk yield and composition and blood metabolites of dairy cows. 48 multiparous Holstein cows were randomly assigned into one of four treatments in a 2×2 factorial arrangement of vitamin E and supplemental dietary fat during the transition period. Treatments were： 1） 1 500 IU d^（-1） vitamin E without fat supplementation（1 500VE-F）; 2） 1 500 IU d^（-1） vitamin E with fat supplement（1 500VE＋F）; 3） 3 000 IU d^（-1） vitamin E without fat supplementation（3 000VE-F）; and 4） 3 000 IU d^（-1） vitamin E with fat supplement（3 000VE＋F）. Dietary treatments were initiated at approximately 28 d before expected calving dates and continued through 28 d postpartum. Dry matter intake（DMI） was unaffected（P〉0.05） by prepartum treatment. Regardless of vitamin E supplementation, DMI was greater（P〈0.01） in fat-supplemented cows compared with un-supplemented cows（19.60 vs. 18.45 kg d^（-1）; SEM=0.42） during the postpartum period. Energy balance and body weight were not affected（P〉0.05） by treatments. Postpartum diets had no significant effect on milk yield or milk composition. Plasma concentrations of non-esterified fatty acids, glucose, and insulin were not affected（P〉0.05） by treatments. Regardless of vitamin E supplementation, plasma β-hydroxybutyrate concentration was greater（P〈0.05） in fat-supplemented cows compared with un-supplemented cows during the postpartum period. These results showed no indication of positive effects on lactation performance associated with vitamin E and dietary fat supplement in transition cows.
基金financially supported by National Natural Science Foundation of China(31272469,31372334)China Agriculture Research System(CARS-37)
文摘Energy intake prepartum is critically important to health, milk performance, and profitability of dairy cows. The objective of this study was to determine the effect of reduced energy density of dose-up diets on dry matter intake （DMI）, lactation performance and energy balance （EB） in multiparous Holstein cows which were housed in a free-stall barn and fed for ad libitum intake. Thirty-nine dry cows were blocked and assigned randomly to three groups fed a high energy density diet [HD, n = 13; 6.8 MJ of net energy for lactation （NEL）/kg; 14.0% crude protein （CP） ], or a middle energy density diet （MD, n = 13; 6.2 MJ NEh/kg; 14.0% CP）, or a low energy density diet （LD, n = 13; 5.4 MJ NEh/kg; 14.0% CP） from d 21 before expected day of calving. After parturition, all cows were fed the same lactation diet to d 70 in milk （DIM）. The DMI and NEE intake prepartum were decreased by the reduced energy density diets （P 〈 0.05）. The LD group consumed 1.3 last 24 h before calving. The milk yield and the postpartum kg/d （DM） more diet compared with HD group in the DMI were increased by the reduced energy density diet prepartum （P 〈 0.05）. The changes in BCS and BW prepartum and postpartum were not affected by prepartum diets HD group had higher milk fat content and lower lactose content compared with LD group during the first 3 wk of lactation （P 〈 0.05）. The energy consumption for HD, MD and LD groups were 149.8%, 126.2% and 101.1 % of their calculated energy requirements prepartum （P 〈 0.05）, and 72.7%, 73.1% and 7.5.2% during the first 4 wk postpartum, respectively. In conclusion, the low energy density prepartum diet was effective in controlling NF_L intake prepartum, and was beneficial in increasing DMI and milk yield, and alleviating negative EB postpartum.
基金Acknowledgements Alea Agrawal is a recipient of a Jonathan Baldwin Turner MS fellowship from the University of Illinois (Urbana-Champaign). Z. Zhou is recipient of a fellowship from China Scholarship Council (CSC) to perform his PhD studies at the University of Illinois (Urbana-Champaign). The funders had no role in the design of the study and collection, analysis, and interpretation of data and in writing of the manuscript.
文摘Background： G-protein coupled receptors（GPCR）, also referred as Free Fatty Acid Receptors（FFAR）, are widely studied within human medicine as drug targets for metabolic disorders. To combat metabolic disorders prevalent in dairy cows during the transition period, which co-occur with negative energy balance and changes to lipid and glucose metabolism, it may be helpful to identify locations and roles of FFAR and other members of the GPCR family in bovine tissues.Results： Quantitative RT-PCR（qPCR） of subcutaneous adipose, liver, and PMNL samples during the transition period（-10, ＋7, and ＋20 or ＋30 d） were used for expression profiling of medium-（MCFA） and long-chain fatty acid（LCFA）receptors GPR120 and GPR40, MCFA receptor GPR84, and niacin receptor HCAR2/3. Adipose samples were obtained from cows with either high（HI; BCS ≥ 3.75） or low（LO; BCS ≤ 3.25） body condition score（BCS） to examine whether FFAR expression is correlated with this indicator of health and body reserves. Supplementation of rumen-protected methionine（MET）, which may improve immune function and production postpartum, was also compared with unsupplemented control（CON） cows for liver and blood polymorphonuclear leukocytes（PMNL） samples. In adipose tissue, GPR84 and GPR120 were differentially expressed over time, while GPR40 was not expressed; in PMNL, GPR40 was differentially expressed over time and between MET vs. CON, GPR84 expression differed only between dietary groups, and GPR120 was not expressed; in liver, GPCR were either not expressed or barely detectable.Conclusions： The data indicate that there is likely not a direct role in liver for the selected GPCR during the transition period, but they do play variable roles in adipose and PMN. In future, these receptors may prove useful targets and/or markers for peripartal metabolism and immunity.
基金The authors acknowledge funding from the Research and Development(R&D)Program(Research Pooling Initiative),Ministry of Education,Riyadh,Saudi Arabia,(RPI-KSU)Authors also extend their appreciation to the Deanship of Scientific Research at King Saud University for partial funding through research project number RG-1436-021Partial support from Hatch funds under project ILLU-538-914(National Institute of Food and Agriculture,Washington,DC)is also acknowledged。
文摘Background:Nutritional management in the dry period can alter body condition score(BCS)in dairy cows,a subjective measure of body fat.As such,differences in BCS during late-pregnancy not only mirror nutrient utilization by fat depots,but also can play important roles on the metabolic and hormonal environment.We investigated the association between cow BCS during late-pregnancy on developmental parameters and blood variables of neonatal calves.Forty-nine multiparous Holstein cows were retrospectively divided by prepartal BCS into normal BCS≤3.25(NormBCS;3.02±0.17,n=30)or high BCS≥3.75(HighBCS;3.83±0.15,n=19)groups.Plasma samples were collected from cows at−10 d relative to parturition.Body weight,hip and wither height,hip width and body length were measured at birth and weekly through weaning(42 d of age)and until 9 weeks of age.Calf blood samples were collected from the jugular vein at birth(before receiving colostrum,0 d),24 h after first colostrum and at 7,21,42 and 50 d of age.The data were subjected to ANOVA using the mixed procedure of SAS.The statistical model included day,BCS,and their interactions.Results:Dry matter intake(kg/d or%of body weight)during the last 4 weeks of pregnancy was lower(P≤0.06)in HighBCS cows.Plasma concentrations of fatty acids,ceruloplasmin,and nitric oxide were greater overall(P<0.05)at d−10 prior to calving in HighBCS cows,and they tended(P=0.08)to have greater concentrations of reactive oxygen metabolites.Birth body weight was lower(P=0.03)in calves born to dams with HighBCS.In addition,plasma concentrations of fatty acids,albumin and urea(P<0.05)were greater in those calves.Although calves born to cows with HighBCS maintained a lower postnatal body weight(P=0.04),hip and wither height,hip width,and body length,there was no difference(P>0.05)in daily starter intake and average daily gain due to maternal BCS.Conclusions:Overall,results highlight an association between BCS during late-gestation on in utero calf development and postnatal growth.A high maternal BCS during late-gestation was associated with lower calf body weights,which could be due to lower maternal intakes and a state of inflammation and metabolic stress.
基金grants from the China-USA Intergovernmental Collaborative Project in S&T Innovation under the National Key R&D Program(No.2018YFE0111700)the China Agricultural Research System(No.CARS-36).
文摘The objective of this study was to investigate the effects of supplementing N-carbamoylglutamate(NCG),an Arg enhancer,on amino acid(AA)supply and utilization and productive performance of early-lactating dairy cows.Thirty multiparous Chinese Holstein dairy cows were randomly divided into con-trol(CON,n=15)and NCG(CON diet supplemented with NCG at 20 g/d per cow,n=15)groups at 4 wk before calving.Diets were offered individually in tie-stalls,and NCG was supplemented by top-dress feeding onto total mixed ration for the NCG group.The experiment lasted until wk 10 after calving.Dry matter intake tended to be higher(P=0.06),and yields of milk(P<0.01),milk protein(P<0.01),and milk fat(P<0.01)were higher in the NCG-cows than in the CON-cows.Plasma activities of aspartate aminotransferase(P<0.01),alanine aminotransferase(P=0.03),and plasma level ofβ-hydroxybutyrate(P=0.04)were lower in the NCG-cows than in the CON-cows,whereas plasma glucose(P=0.05)and nitric oxide(NO,P<0.01)concentrations were higher.Coccygeal vein concentrations of Cys(P<0.01),Pro(P<0.01),Tyr(P=0.05),most essential AA except Thr and His(P<0.01),total essential AA(P<0.01),and total AA(P<0.01)were higher in the NCG-cows than in the CON-cows.The arterial supply of all AA was greater in the NCG-cows than in the CON-cows.The NCG-cows had higher mammary plasma flow of AA(P=0.04)and clearance rate of Cys(P<0.01),Pro(P<0.01)and Asp(P<0.01),and higher ratios of uptake to output of Met(P=0.05),Lys(P<0.01),Cys(P=0.01),Pro(P=0.03),and Asp(P=0.01).In summary,addition of NCG initiated from the prepartum period improved the lactation performance of postpartum dairy cows,which might attribute to greater Arg and NO concentrations,as well as improved AA supply and utilization,liver function,and feed intake in these cows.
基金financially supported by grants from the ChinaUSA Intergovernmental Collaborative Project in S&T Innovation under the National Key R&D Program(Grant No.2018YFE0111700)the China Agricultural Research System(Grant No.CARS-36)。
文摘The objective of this study was to investigate whether supplementation with N-carbamoylglutamate(NCG)to cows during late gestation alters uteroplacental tissue nutrient transporters,calf metabolism and newborn weight.Thirty multiparous Chinese Holstein cows were used in a randomized complete block design experiment.During the last 28 d of pregnancy,cows were fed a diet without(CON)or with NCG(20 g/d per cow).The body weight of calves was weighed immediately after birth.Placentome samples were collected at parturition and used to assess mRNA expression of genes involved in transport of arginine,glucose,fatty acid and angiogenesis factors,as well as the mammalian target of rapamycin(mTOR)pathway.Blood samples of calves before colostrum consumption were also collected for the detection of plasma parameters,amino acids(AA)and metabolomics analysis.The newborn weight(P=0.02)and plasma Arg concentration of NCG-calves was significantly higher(P=0.05)than that of CON-calves,and the plasma concentrations of urea nitrogen tended to be lower(P=0.10)in the NCG group.The mRNA abundance of genes involved in glucose transport(solute carrier family 2 member 3[SLC2 A3],P<0.01),angiogenesis(nitric oxide synthase 3[NOS3],P=0.02),and mTOR pathway(serine/threonine-protein kinase 1[ACT1],P=0.10;euka ryotic translation initiation factor 4 B pseudogene 1[EIF4 BP1],P=0.08;EIF4 EBP2,P=0.04;and E74-like factor 2[ELF2],P=0.03)was upregulated in the placentome of NCG-supplemented cows.In addition,17 metabolites were significantly different in the placentome of NCG-supplemented cows compared to non-supplemented cows,and these metabolites are mainly involved in arginine and proline metabolism,alanine,aspartate and glutamate metabolism,and citrate cycle.In summary,the increased body weight of newborn calves from the NCG supplemented dairy cows maybe attributed to the increased angiogenesis and uteroplacental nutrient transport and to the activated mTOR signal pathway,which may result in the increased nutrient supply to the fetus,and improved AA metabolism and urea cycle of the fetus.
