吡啶羧酸铬对热应激期奶牛乳成分和乳中铬沉积的影响

Effects of Chromium Picolinate on the Composition and Deposit of Chromium in Milk of Cattle under Heat Stress

依据体质量、泌乳天数、产奶量相似的原则,选择20头泌乳中期(产后165 d)的荷斯坦奶牛,采用单因子区组设计,将其分成4组,分别补充不同梯度的吡啶羧酸铬,研究其对热应激期奶牛乳成分和铬沉积的影响,以探索富铬牛奶的生产途径。结果表明,奶牛日粮中添加吡啶羧酸铬4,8,12 mg/(头·d)对牛奶常规成分(乳脂率、乳蛋白、乳糖、总固形物)无显著影响(P>0.05);对牛奶中铬沉积影响不大(P>0.05)。热应激期奶牛日粮中添加8,12 mg/(头·d)水平的吡啶羧酸铬,对减缓奶牛热应激、提高产奶量效果明显(P<0.05)。

A total of 20 lactating holstein cattle which in middle lactation（165 d after parturition）with similar body weight,lactation days and milk yield were paired with a single factor.The test groups were respectively added different levels chromium picolinate to study the effects of chromium picolinate on the composition and deposit of chromium in milk of cattle under heat stress.The results showed that：there was little effect on the chromium content in milk（P〉0.05）for cattle under heat stress with a dietary supplementation of chromium picolinate at 4,8,12 mg/（each one·d）;there was no significant effect（P〉0.05）on conventional ingredients in milk（milk fat,milk protein,lactose,total solids）;there were notable effects to retart heat stress（P〈0.05）and increase milk yield（P〈0.05）with 8,12 mg（/each one·d）chromium picolinate in die of cattle under heat stress.