不同苹果渣水平对关中奶山羊泌乳性能、养分表观消化率、血清生化指标及瘤胃液pH值的影响

Effects of different apple pomace levels on lactation performance,nutrient apparent digestibility,serum biochemical indices and the rumen pH of Guanzhong dairy goats

为研究饲粮中添加不同苹果渣水平对关中奶山羊泌乳性能、养分表观消化率、血清生化指标及瘤胃液pH值的影响,选取体重[(50.81±1.53)kg]、胎次(第3胎)、产奶量[(2.15±0.05)kg·d^(-1)]、泌乳日期[(125.00±2.51)d]相近或一致的健康关中奶山羊50只,随机分成5组,每组10只羊,每只羊为1个重复。各组苹果渣添加比例分别为0(对照)、9%、18%、27%和36%。试验预试期10 d,正试期60 d。结果表明:18%和27%组的产奶量和4%校正乳产量均极显著高于0(对照)、9%、36%组(P<0.01);各组干物质采食量无显著性差异(P>0.05);各组间乳脂率、乳蛋白率、乳糖率无显著性差异(P>0.05);18%组粗蛋白表观消化率显著高于0(对照)、9%组(P<0.05),18%组中性洗涤纤维表观消化率显著高于0(对照)、27%和36%(P<0.05);各组间血清总蛋白、血清葡萄糖、血清甘油三酯、血清尿素氮无显著性差异(P>0.05);瘤胃液pH值随着苹果渣添加比例的增加而降低,9%、18%、27%、36%组的瘤胃液pH值均显著低于对照(P<0.05)。由此可见,饲粮中添加适量苹果渣可以提高关中奶山羊的产奶量,4%校正乳产量,粗蛋白与中性洗涤纤维表观消化率等指标,降低瘤胃液pH值,改善羊乳品质和血清生化指标,苹果渣作为一种新型饲料资源可以开发利用,且在本试验中,饲粮中苹果渣的添加水平为18%时效果最佳。

This experiment investigated the effects of different apple pomace levels on lactation performance,milk quality,serum biochemical indices and the rumen pH of Guanzhong dairy goats.Fifty healthy Guanzhong dairy goats with similar weight(50.81±1.53)kg,parities(3 parities),days in milk[(125.00±2.51)d]and milk yield[(2.15±0.05)kg·d^(-1)]were assigned to 5 groups with 10 goats per group and one goat per replicate.Goats in the five groups were fed the experimental diets which were 0(control),9%,18%,27%and 36%apple pomace.The pre-experiment diet adaptation period lasted for 10 days,and the formal experiment lasted for 60 days.It was found that:Milk yield and 4%fat corrected milk in the 18%and 27%groups were significantly higher than those of control group,9%group and 36%group(P<0.01).There were no significant differences in dry matter intake among groups(P>0.05).No significant differences were observed in milk fat percentage,milk protein percentage and lactose percentage among groups(P>0.05).The apparent digestibility of crude protein in the 18%group was significantly higher than in the control group and the 9%group(P<0.05),while the apparent digestibility of neutral detergent fiber in the 18%group was significantly higher than in the control,9%and 36%groups(P<0.05).No significant differences were observed in serum total protein,serum glucose,serum triglyceride and serum urea nitrogen among groups(P>0.05).The rumen pH was decreased with increase in the proportion of supplemental apple pomace,and 9%,18%,27%and 36%groups all had significantly lower(P<0.05)rumen pH than the control group.In conclusion,dietary supplementation of apple pomace improved milk yield,4%fat corrected milk,apparent digestibility of crude protein and neutral detergent fiber,decrease the rumen pH,and improve milk quality and serum biochemical indices,which suggests that apple pomace can be used as a new type of feed resource for Guanzhong dairy goats,and the optimal supplemental level is 18%.