脂溶性维生素对杜寒杂交肉羊育肥阶段生长性能和消化代谢的影响

Effects of Fat-Soluble Vitamins on Growth Performance and Digestion and Metabolism of Dorper×Thin-Tailed Han Crossbred Sheep during Fattening Stage

本试验通过研究饲粮中部分扣除或过量添加脂溶性维生素(维生素A、维生素D、维生素E)对杜寒杂交肉羊育肥阶段生长性能、营养物质表观消化率、氮和能量代谢的影响,旨在为我国肉羊饲养标准中脂溶性维生素需要量参数的制订提供依据。采用单因素试验设计,选择120只90日龄断奶后体重为(26.0±0.1) kg的杜寒杂交肉羊,根据体重随机分为5组,每组12个重复,每个重复2只(公母各占1/2)。对照组(PC组)饲喂基础饲粮,不扣除任何维生素;试验组分别在PC组基础上扣除30%的维生素A(PC-VA组)、维生素D(PC-VD组)和维生素E(PC-VE组);另设过量添加组,其3种脂溶性维生素添加量均为对照组的7.5倍(PC-7.5组)。预试期10 d,试验期90 d。结果表明:第60～90天,PC-VE组公羊干物质采食量(DMI)最低,显著低于其他各组(P<0.05); PC-7.5组母羊平均日增重(ADG)最低,显著低于其他各组(P <0.05); PC-7.5组母羊饲料转化率(FCR)最高(P <0.05),显著高于其他各组(P <0.05)。部分扣除维生素E和试验周期对公羊DMI和ADG存在显著交互作用(P<0.05);摄入高倍剂量脂溶性维生素和试验周期对母羊ADG和FCR存在显著交互作用(P<0.05);摄入高倍剂量脂溶性维生素和试验周期对肉羊的干物质、有机物、粗蛋白质和酸性洗涤纤维的表观消化率存在显著交互作用(P<0.05)。结果提示,饲粮长期扣除30%的维生素E或摄入过量的脂溶性维生素可降低杜寒杂交肉羊增重和营养物质表观消化率,对肉羊生长性能产生负面影响。

The purpose of this experiment was to investigate the effect of partial deduction or excess amount of fat-soluble vitamins (vitamin A,vitamin D and vitamin E) on growth performance,nutrient apparent digestibility,nitrogen and energy metabolism of Dorper×thin-tailed Han crossbred sheep during fattening period,with an aim to provide theoretical basis for the establishment of fat-soluble vitamin requirements of sheep in China.A total of 120 Dorper×thin-tailed Han crossbred sheep (half male and half female) with average body weight of (26.0±0.11) kg after weaning at 90 days of age were used in the current study according to a single factor experimental design. All sheep were randomly divided into 5 groups according to their body weight with 12 replicates per group and 2 sheep per replicate (half male and half female). The control group (PC group) fed a basal diet with no deduction vitamins;30% of vitamin A (PC-VA group),vitamin D (PC-VD group) and vitamin E (PC-VE group) were deducted from PC group in the experimental groups,respectively;a high-dose group (PC-7.5 group) was set up which all fat-soluble vitamins were 7.5 times higher than that of the control group. The pre-experimental period lasted for 10 days,and the experimental period lasted for 90 days. The results showed that during days 60 to 90 of the experiment,the dry matter intake (DM I) and average daily gain (ADG) of rams in PC-VE group were the lowest,and significantly lower than those in other groups (P <0.05);the ADG of ewes in PC-7. 5 group was the lowest,and significantly lower than that in other groups (P<0.05);and the feed conversion ratio (FCR) of ewes in PC-7.5 group was the highest,and significantly higher than that in other groups (P<0.05). Partial deduction of vitamin E and experimental period interactively affected DM I and ADG or rams (P<0.05);excess amount of fat-soluble vitamins and experimental period interactively affected ADG and FCR of ewes (P<0.05);excess amount of fat-soluble vitamins and experimental period interactively affected the apparent digestibility of dry matter,organic matter,crude protein and acid detergent fiber of sheep (P<0.05). The results suggeste that long-term deduction of 30% of vitamin E or excess amount of fat-soluble vitamins can reduce the weight gain and nutrient digestibility of Dorper ×thin-tailed Han crossbred sheep,and negatively affect the growth performance of sheep.