不同β-受体激动剂添加模式对肉牛血液生化指标和激素水平的影响

Different Feeding Mode of β-agonists Treatments on Plasma Biochemical Parameters and Internal Hormone Levels in Cattle

试验旨在研究不同β-受体激动剂添加模式对肉牛血液生化指标和激素水平的影响。选取15头体况良好、体重相近(257.9kg±33.3kg)的西门塔尔肉牛,随机分为3组,每组5头。对照组饲喂基础日粮;试验Ⅰ组添加莱克多巴胺,添加剂量为670.0μg/kg体重;试验Ⅱ组添加莱克多巴胺、沙丁胺醇和克伦特罗的混合物,添加剂量分别为223.3、50.0、5.3μg/kg体重。给药期28d,停药期28d。结果表明,与对照组相比,在给药第28天时,试验Ⅰ组肉牛血浆中游离脂肪酸(FFA)浓度显著降低(P<0.05),试验Ⅱ组肉牛血浆中葡萄糖(GLU)和游离脂肪酸浓度均显著降低(P<0.05);整个试验过程中,除停药第28天时试验Ⅰ组肉牛血浆中胰岛素(INS)水平显著高于对照组外(P<0.05),β-受体激动剂对各试验组血浆中激素水平均无显著影响(P>0.05)。综合上述试验结果,肉牛血浆中的FFA可作为β-受体激动剂潜在的生物标志物,可通过对其的监测来监管β-受体激动剂在肉牛生产环节中的非法使用。

The experiment was aimed to study different feeding mode ofβ-agonists treatments on plasma parameters and internal hormone levels in cattle.15 healthy Simontal cattle with similar body weight（257.9kg±33.3kg）were randomly divided into three groups.The cattle were fed with the same basal diet,and the test groupⅠ were daily treated with 670.0μg/（kg·BW）ractopamine while the test group Ⅱ were daily treated with a mixture of ractopamine,salbutamol and clenbuterol（223.3,50.0and 5.3μg/（kg·BW）,respectively）for 28 consecutive days,and the period of withdrawal was 28 days.The results showed that at the 28 th day of the treatment,plasma free fatty acid（FFA）concentrations in test groupsⅠwere significantly lower than that in control group（P〈0.05）,plasma glucose（GLU）and FFA concentrations in test groupsⅡwere significantly lower than that in control group（P〈0.05）;The levels of hormone in plasma were not significantly affected byβ-agonists during the whole test period（P〉0.05）except that the INS level in test groupsⅠ was significantly lower than that in control group（P〈0.05）at the28 th day of the withdrawal.These results demonstrated that plasma FFA in cattle could be used as potential biomarkers to supervise the illegal use ofβ-agonists.