日粮霉菌毒素吸附剂添加水平对奶牛营养物质表观消化率和血液指标的影响

Effects of Mycotoxin Absorbent on the Blood Indices and Nutrients Apparent Digestibility of Lactating Dairy Cows

试验旨在研究日粮中添加霉菌毒素吸附剂蒙脱石对中国荷斯坦奶牛营养物质表观消化率和血液指标的影响。选择45头胎次、泌乳日龄和产奶量相近的健康荷斯坦奶牛,采用随机区组设计分为5组,每组9头,分别在基础日粮中添加0%(对照组)、0.5%、1.0%、1.5%和2.0%的蒙脱石,试验期70 d,测定各组的饲料营养物质表观消化率、血液中酶和矿物元素含量的变化。结果表明:随着蒙脱石添加量的增大,血清中谷草转氨酶浓度无显著变化(P>0.05),但0.5%组血清中谷丙转氨酶和碱性磷酸酶的浓度显著低于对照组(P<0.05);血液中锌和镁浓度无显著变化,但1.0%~2.0%组血液中钙浓度均显著高于对照组(P<0.05),铜和铁浓度显著低于对照组(P<0.05);对粗脂肪、钙和总磷的表观消化率无显著影响,但粗蛋白质表观消化率有升高趋势,且0.5%组的NDF、ADF表观消化率最高。综合考虑,本试验条件下(奶牛日粮中霉菌毒素含量在安全范围内),日粮中霉菌毒素吸附剂蒙脱石的推荐添加量为0.5%。

The objective of this study was to investigate the effects of mycotoxin absorbent on the blood indices and apparent digestibility of the lactation Holstein dairy cows. It could provide some instructions for its application in feed industry. Forty-five multiparous Holstein dairy cows, blocked by parity, days in milk （DIM） and milk yield, were allocated into five treatments with 9 replicates per treatment in a randomized block experiment. Cows were fed basal diet （containing 3.0 p.g/kg total aflatoxin and 105 p^g/kg zearalenone, dry matter basis） with： 0% （control group）, 0.5%, 1.0%, 1.5% and 2.0% montmorillonite, respectively. The results showed that there were no significant differences in glutamic-oxalacetie transaminease （PM）.05）. However, comparing with the control group, 0.5% group significantly lowered the content of aminotransferase and alkaline phosphatase （P〈0.05）; Zinc and magnesium concentration were not significantly affected by montmorillonite. However, it significantly reduced the blood concentration of copper and iron （P〈0.05）, increased the calcium concentration in 1.0%-2.0% treatments comparing with the control group （P〈0.05）; There were no significant differences in the apparent digestibility of calcium, phosphorus, crude fat, ADF and gross energy（P〉0.05）, but the apparent digestibility of crude protein increased with the adding doses. Considering all of this above, the optimize supplemental level of montmorillonite in the ration for dairy cows should be 0.5%.