Lauric acid(LA)has the possibility to improve milk production in dairy cows by improving mammary gland development,however,the mechanism by which it might regulate mammary gland development is unclear.The influence of...Lauric acid(LA)has the possibility to improve milk production in dairy cows by improving mammary gland development,however,the mechanism by which it might regulate mammary gland development is unclear.The influence of LA on milk production,nutrient digestibility and the expression of proteins related to mammary gland development in dairy cows were evaluated.Forty primiparous Holstein dairy cows were divided into 4 groups in a randomized block design.Four treatments included the control(0 g/d LA per cow),low-LA(100 g/d LA per cow),medium-LA(200 g/d LA per cow),and high-LA(300 g/d LA per cow).Yields of milk,fat-corrected milk,and energy-corrected milk quadratically increased(P<0.05),and yield and content of milk fat linearly increased(P<0.05)with LA supplementation.Percentages of C12:0,C18:1 and C20:1 fatty acids in milk fat linearly increased(P<0.05),but that of C16:0 fatty acid linearly decreased(P=0.046).Supplementation of LA led to a linear and quadratical increase(P<0.05)in digestibility of dry matter,organic matter,neutral detergent fibre and acid detergent fibre,and ruminal total volatile fatty acid concentration but a linear reduction(P=0.018)in the ratio of acetate to propionate.The enzymatic activities of ruminal pectinase,xylanase,andα-amylase,and populations of total bacteria and anaerobic fungi increased linearly(P<0.05),while populations of total protozoa and methanogens decreased linearly(P<0.05)with increased LA addition.Following LA addition,blood glucose,triglyceride,estradiol,prolactin,and insulin-like growth factor 1 concentrations increased linearly(P<0.05)and albumin and total protein concentrations increased quadratically(P<0.05).Moreover,addition of 200 g/d LA promoted(P<0.05)the expression of protein involved in mammary gland development and fatty acids synthesis.These results suggested that LA addition enhanced milk production and fatty acids synthesis by stimulating nutrient digestion,the expression of proteins associated with milk fat synthesis and mammary gland development.展开更多
This experiment was to evaluate the influence of sodium butyrate(SB)addition on milk production,ruminal fermentation,nutrient digestion,and the development and metabolism regulation of the mammary gland in dairy cows....This experiment was to evaluate the influence of sodium butyrate(SB)addition on milk production,ruminal fermentation,nutrient digestion,and the development and metabolism regulation of the mammary gland in dairy cows.Forty Holstein dairy cows averaging 710±18.5 kg body weight,72.8±3.66 d in milk(DIM),and 41.4±1.42 kg/d milk production were divided into four treatments blocked by DIM and milk production.Treatments were control group,low SB,medium SB,and high SB with 0,100,200 and 300 g/d of SB addition per cow,respectively.The study lasted for 105 d.Production of milk,milk protein and lactose quadratically increased(P<0.05),while fat-corrected milk,energycorrected milk and milk fat yields linearly increased(P<0.05)with increasing SB addition.The digestibility of dietary dry matter,organic matter,and crude protein linearly increased(P<0.05),whereas the digestibility of ether extract,neutral detergent fibre,and acid detergent fibre quadratically increased(P<0.05).Ruminal pH quadratically decreased(P=0.04),while total volatile fatty acids(VFA)quadratically increased(P=0.03)with increasing SB addition.The acetic acid to propionic acid ratio increased(P=0.03)linearly due to the unaltered acetic acid molar percentage and a linear decrease in propionic acid molar percentage.Ruminal enzymatic activity of carboxymethyl-cellulase and a-amylase,populations of total bacteria,total anaerobic fungi,total protozoa,Ruminococcus albus,R.flavefaciens,Butyrivibrio fibrisolvens,Fibrobacter succinogenes,and Ruminobacter amylophilus linearly increased(P<0.05).Blood glucose,urea nitrogen,and non-esterified fatty acids linearly decreased(P<0.05),while total protein concentration linearly increased(P=0.04).Moreover,the addition of SB at 200 g/d promoted(P<0.05)mRNA and protein expression of PPARγ,SREBF1,ACACA,FASN,SCD,CCNA2,CCND1,PCNA,Bcl-2,GPR41,and the ratios of p-Akt/Akt and p-mTOR/mTOR,but decreased(P<0.05)mRNA and protein expressions of Bax,caspase-3,and caspase-9.The results suggest that milk production and milk fat synthesis increased with SB addition by stimulating rumen fermentation,nutrient digestion,gene and protein expressions concerned with milk fat synthesis and mammary gland development.展开更多
基金funded by the Education Department of Shanxi Province,Excellent Doctor Work Award Fund Research Project[SXYBKY2018036]Modern Agro industry Technology Research System of Shanxi Province (2023CYJSTX13).
文摘Lauric acid(LA)has the possibility to improve milk production in dairy cows by improving mammary gland development,however,the mechanism by which it might regulate mammary gland development is unclear.The influence of LA on milk production,nutrient digestibility and the expression of proteins related to mammary gland development in dairy cows were evaluated.Forty primiparous Holstein dairy cows were divided into 4 groups in a randomized block design.Four treatments included the control(0 g/d LA per cow),low-LA(100 g/d LA per cow),medium-LA(200 g/d LA per cow),and high-LA(300 g/d LA per cow).Yields of milk,fat-corrected milk,and energy-corrected milk quadratically increased(P<0.05),and yield and content of milk fat linearly increased(P<0.05)with LA supplementation.Percentages of C12:0,C18:1 and C20:1 fatty acids in milk fat linearly increased(P<0.05),but that of C16:0 fatty acid linearly decreased(P=0.046).Supplementation of LA led to a linear and quadratical increase(P<0.05)in digestibility of dry matter,organic matter,neutral detergent fibre and acid detergent fibre,and ruminal total volatile fatty acid concentration but a linear reduction(P=0.018)in the ratio of acetate to propionate.The enzymatic activities of ruminal pectinase,xylanase,andα-amylase,and populations of total bacteria and anaerobic fungi increased linearly(P<0.05),while populations of total protozoa and methanogens decreased linearly(P<0.05)with increased LA addition.Following LA addition,blood glucose,triglyceride,estradiol,prolactin,and insulin-like growth factor 1 concentrations increased linearly(P<0.05)and albumin and total protein concentrations increased quadratically(P<0.05).Moreover,addition of 200 g/d LA promoted(P<0.05)the expression of protein involved in mammary gland development and fatty acids synthesis.These results suggested that LA addition enhanced milk production and fatty acids synthesis by stimulating nutrient digestion,the expression of proteins associated with milk fat synthesis and mammary gland development.
基金This work was funded by Education Department of Shanxi Province(Grant no.SXYBKY2018036)the Animal Husbandry‘1331 project’Key Discipline Construction Special Project of Shanxi Province.
文摘This experiment was to evaluate the influence of sodium butyrate(SB)addition on milk production,ruminal fermentation,nutrient digestion,and the development and metabolism regulation of the mammary gland in dairy cows.Forty Holstein dairy cows averaging 710±18.5 kg body weight,72.8±3.66 d in milk(DIM),and 41.4±1.42 kg/d milk production were divided into four treatments blocked by DIM and milk production.Treatments were control group,low SB,medium SB,and high SB with 0,100,200 and 300 g/d of SB addition per cow,respectively.The study lasted for 105 d.Production of milk,milk protein and lactose quadratically increased(P<0.05),while fat-corrected milk,energycorrected milk and milk fat yields linearly increased(P<0.05)with increasing SB addition.The digestibility of dietary dry matter,organic matter,and crude protein linearly increased(P<0.05),whereas the digestibility of ether extract,neutral detergent fibre,and acid detergent fibre quadratically increased(P<0.05).Ruminal pH quadratically decreased(P=0.04),while total volatile fatty acids(VFA)quadratically increased(P=0.03)with increasing SB addition.The acetic acid to propionic acid ratio increased(P=0.03)linearly due to the unaltered acetic acid molar percentage and a linear decrease in propionic acid molar percentage.Ruminal enzymatic activity of carboxymethyl-cellulase and a-amylase,populations of total bacteria,total anaerobic fungi,total protozoa,Ruminococcus albus,R.flavefaciens,Butyrivibrio fibrisolvens,Fibrobacter succinogenes,and Ruminobacter amylophilus linearly increased(P<0.05).Blood glucose,urea nitrogen,and non-esterified fatty acids linearly decreased(P<0.05),while total protein concentration linearly increased(P=0.04).Moreover,the addition of SB at 200 g/d promoted(P<0.05)mRNA and protein expression of PPARγ,SREBF1,ACACA,FASN,SCD,CCNA2,CCND1,PCNA,Bcl-2,GPR41,and the ratios of p-Akt/Akt and p-mTOR/mTOR,but decreased(P<0.05)mRNA and protein expressions of Bax,caspase-3,and caspase-9.The results suggest that milk production and milk fat synthesis increased with SB addition by stimulating rumen fermentation,nutrient digestion,gene and protein expressions concerned with milk fat synthesis and mammary gland development.
