阴离子盐对奶牛围产期血浆离子平衡的影响

采用20头荷斯坦经产奶牛按配对试验设计,研究在干奶后期(产前约3周)添加阴离子盐添加剂对奶牛产前1周、2周和产后1周、2周及分娩当日血浆离子浓度、胎衣不下发病率以及产乳热发病情况的影响。结果表明,饲喂阴离子盐日粮4d后可使尿液pH值显著降低(P<0.05),试验组与对照组比较产前一周和产后一周血浆钙离子浓度有上升的趋势,分别为(7.98vs7.26)和(7.81vs7.19),距分娩1周血浆镁离子浓度有降低趋势(1.96vs2.16),在分娩当日试验组血浆镁离了浓度低于对照组(1.90vs2.01),产前1周和分娩当日血浆钠离子浓度低于对照组,分别为(123.90vs126.43,P<0.05)和(124.28vs125.93,P<0.05)。在本试验条件下添加阴离子盐对血浆其他离子浓度没有显著影响(P>0.05),通过对胎衣不下发生情况的统计表明,饲喂阴离子盐能够减少胎衣不下的发生。

Effect of anionic salts in prepartum diets on the plasma ion balance status of prepartum dairy cows

Twenty Holstein breed cows were randomly assigned to anionic salt or control prepartum diet to investigate the effect of anionic salt addition on blood ion concentrations,retained placenta incidence,and milk fever. The urinary pH value of the cows fed the anionic salt diet dropped quickly to 7 below after 4 days feeding,and was singnificantly lower than that of the cow fed the control diets (P<0.05).tended to increase the concentration of Ca2 (7.98vs7.26)and(7.81vs7.19)before parturition 1 week and after parturition 1 week ,tended to deccrdased the concentration of Mg2 in the plasma(1.96vs2.16)before parturition 1 week and decreased Mg2 in the plasma on parturition day(1.90vs2.01),Feeding anionic salt diets decreased the concentration of Na in the plasma(123.90vs126.43,P<0.05)and(124.28vs125.93,P<0.05)before parturition 1 week and parturition day,but has no significant influence on the content of other ion in the plasma. As anionic salt diets were fed,the retained placenta incidence decreased 10 percentage units compared with the conrtol diet.