丙酸钙对泌乳早期奶牛泌乳性能和代谢产物的影响

Effects of calcium propionate supplementation on lactation performance and metabolites in early lactation Holstein dairy cows

选用32头经产奶牛,根据泌乳期、上个泌乳期305 d产奶量和预产期,采用随机区组设计分为4组,对照组饲喂基础日粮,处理1、2、3组分别在基础日粮基础上添加丙酸钙100、200、300 g/d。结果显示,日粮添加丙酸钙对奶牛的采食量、乳脂率、乳蛋白率、乳糖率和乳干物质率无显著影响,200、300 g/d组产奶量和饲料转化效率显著高于对照组(P<0.05)。200、300 g/d组血浆葡萄糖和胰岛素浓度显著高于对照组(P<0.05),而血浆游离脂肪酸和β-羟丁酸浓度显著低于对照组(P<0.05);200、300 g/d组尿酮浓度显著低于对照组和100 g/d组(P<0.05)。试验结果表明,丙酸钙适宜添加量为200 g/d。

Thirty-two multiparous Holstein dairy cows,blocked by lactation number, corrected milk yield in last lactation,and expected calving date,were designated into four treatments in a randomized block experiment. The additive levels （0,100,200,and 300 g/d） of calcium propionate were graded in the four treatments. The results showed that average feed intake, milk fat percentage, milk protein percentage,milk lactose percentage and milk dry matter percentage were not affected significantly by calcium propionate supplementation （P〉0.05）. Milk yield and feed efficiency of cows supplemented calcium propionate at 200 g/d and 300 g/d were higher than those of cows supplemented calcium propionate at 100 g/d and fed control diet significantly （P〈0.05）. Concentrations of glucose and insulin in plasma of cows supplemented calcium propionate at 200 g/d and 300 g/d were higher than those cows fed control diet significantly （P〈0.05）. Concentrations of non-esterified fatty acids and β-hydroxybutyrate in plasma of cows supplemented calcium propionate at 200 g/d and 300 g/d were lower than of cows fed control diet significantly （P〈 0.05）. Concentrations of urine ketones of cows supplemented calcium propionate at 200 g/d and 300 g/d were lower than that of cows supplemented calcium propionate at 100 g/d and fed control diet significantly （P〈0.05）. These results indicated that the optimal dose of was 200 g/d calcium propionate supplementation.