为了研究不同营养调控方式对牦牛僵牛体尺和胃肠道发育的影响。选择1周岁、平均体重(54.24±9.24) kg(较同龄同品种牦牛群体平均体重低1.5倍标准差)的青海高原型牦牛僵牛20头,按体重随机分为4组,分别设为屠宰对照组、精料组(补饲精料)、舔砖组(补饲精料+舔砖)、半胱胺组(补饲精料+半胱胺),另选取5头1周岁、平均体重(75.34±2.43) kg的同品种正常牦牛为正常对照组(补饲精料)。预饲14 d后对屠宰对照组牦牛屠宰取样,正式试验84 d后对其余各组屠宰取样。结果表明:1)各组牦牛的精料、粗料和干物质的采食量及营养物质摄入量差异均不显著(P>0.05)。2)与屠宰对照组相比,84 d的饲养均促进牦牛体尺增加。舔砖组、半胱胺组体高与正常牦牛组无显著差异(P>0.05);试验组牦牛僵牛的体斜长、胸深与正常对照组无显著差异(P>0.05),其中,半胱胺组高于正常对照组。3)营养调控能促进牦牛僵牛各胃室发育。试验组网胃和皱胃重量与正常对照组差异不显著(P>0.05)。半胱胺组瘤胃重量最高,占复胃总重比例最高,并与正常对照组无显著差异(P>0.05)。4)营养调控促进了牦牛僵牛肠道各段的发育,其中舔砖组和半胱胺组同正常对照组差异均不显著(P>0.05)。结果提示,补饲精料促进了牦牛僵牛生长及胃肠道发育,此基础上补饲舔砖和半胱胺使牦牛僵牛上述指标接近或超过正常牦牛。

In order to investigate the effects of different nutritional regulations on body measurements and gastrointestinal tract development of yaks with growth retardation, twenty 1-year-old Qinghai high plateau yaks with growth retardation [average body weight=(54.24±9.24) kg, which was 1.5-fold standard deviations less than the average weight of yak groups with same age and breed] were randomly selected and assigned into 4 groups. They were slaughter control group, concentrate group (supplemented with concentrate), lick block group (supplemented with concentrate + lick block) and cysteamine group (supplemented with concentrate + cysteamine). In addition, another five 1-year-old Qinghai high plateau yaks with normal growth performance [average body weight = (75.34±2.43) kg] were selected as normal control group (supplemented with concentrate). After 14-day adaptation, yaks in slaughter control group were slaughtered and sampled. After 84 days of formal feeding experiment, yaks in the other groups were slaughtered and sampled. The results showed as follows: 1) no significant differences were obtained in feed intake of concentrate, roughage and dry matter, and nutrient intake among all groups (P>0.05). 2) In contrast with slaughter control group, body measurements of yaks increased to different extents after 84 days feeding. In contrast with normal control group, body height of lick block group and cysteamine group was not significantly different (P>0.05); body length and chest depth of experimental groups were not significantly different (P>0.05), and cysteamine group was slightly higher. 3) Nutritional regulations could promote the growth of stomachus compositus of yaks with growth retardation. In contrast with normal control group, no significant differences were obtained in reticulum and abomasum weight of experimental groups (P>0.05). Cysteamine group had the highest rumen weight, accounting for the maximum percentage in total stomachus compositus weight, and those were not significantly different from normal control group (P>0.05). 4) Nutritional regulations could promote the growth of different intestinal tract segments of yaks with growth retardation. In contrast with normal control group, no significant differences were obtained in the weight of different intestinal tract segments of lick block group and cysteamine group (P>0.05). The results indicate that concentrate supplementation promote the growth of body measurements and gastrointestinal tract, and further supplementation of lick block and cysteamine increase these indexes of yaks with growth retardation and even exceeded yaks with normal growth performance.