不同能氮比精料对藏羊生长性能和血清指标的影响

The effect of supplementation of concentrates with different energy-to-nitrogen ratios on growth performance and serum indices in Tibetan sheep

为了研究青海省河南县牧区冬季和春季低质粗料供给条件下不同能氮比(RDN/FOM)精料对泌乳期藏羊生长性能及血清指标的影响、确定最适的RDN/FOM精料,试验在舍饲条件下选取2岁泌乳期藏羊45只,分为3组,分别补饲3种不同RDN/FOM(1组25.00,2组30.01,3组35.06)的精料,测定体重及血清相关指标。结果表明:补饲3种RDN/FOM水平精料后藏羊体重均显著增长(P<0.05),其中RDN/FOM为30.01的2组日增重最为明显,显著高于1组和3组(P<0.05)。三个组血清生化指标中谷丙转氨酶、谷草转氨酶活性及总蛋白、尿素氮含量均有不同程度升高;2,3组肌酐、总胆固醇、三酰甘油略有降低。说明补饲改善了泌乳期藏羊的生长性能,适宜RDN/FOM的精料对藏羊的生长性能有显著的提高效果,RDN/FOM过高或过低的精料都不能使泌乳期藏羊的生长性能达到最优。RDN/FOM为30.01的补饲精料较适宜。

To study the effect of supplementation of concentrates with different energy -to -nitrogen ratios （RDN/FOM）on growth performance and serum biochemical indexes in lactating Tibetan sheep in pastoral areas ntry of Henan Country of Qinghai Province where only low - quality roughages were supplied in winter and spring. To determine the appropriate feed proportion RDN/FOM, the present experiment contained forty - five lactating Tibetan sheep of 2 years old under the condition of stall - feeding. All animals were divided into three groups and were supple- mented with concentrates with three RDN/FOM levels of 25.00 （ group 1 ） ,30.01 （ group 2） and 35.06 （ group 3 ） each. Body weights and serum indices were determined during the experiment. The results showed that average weights of Tibetan sheep increased significantly in each group （P 〈 0.05 ）, and group 2 with 30.01 RDN/FOM was the most obvious in weight gain,significantly higher than group 1 or group 3 （P 〈0.05 ）. Serum biochemical indexes of alanine transa minase, aspartate a minotransferase and total protein, blood urea nitrogen contents also increased in different extent in all three groups,while those indexes of creatinine, total cholesterol and triglyceride slightly reduced in each group. The results indicated that lactating Tibetan sheep in pastoral areas can achieve better growth performance when they were timely supplied concentrates. An appropriate RDN/FOM could improve growth performance significantly. Concentrates with higer or lower RDN/FOM could not reach the best growth performance and group 2 with 30.01 RDN/FOM was the most appropriate.