Effects of supplemental level on serum biochemical indexes and body weight of Gansu Alpine Merino lambs

According to the lactation yields (0.8, 1.0 and 1.2 kg, respectively) and feeding standard of 40 kg Chinese Merino lactation ewes, three daily rations (Ⅰ, Ⅱ and Ⅲ) with different nutritional levels corresponding to the forage to concentrate ratios of 5∶5, 6∶4 and 7∶3 were confected in this study. These rations were used to conduct grazing supplementary feeding experiment in winter and spring for Gansu Alpine Merino, and those lactation ewes of feeding a small amount of concentrates, niblet and large number of green hay were designed as control group. By measuring the serum biochemical indicators of experimental sheep from each group and the change of body weight of ewes and lambs of Gansu Alpine Merino, this study aimed to explore an appropriate forage supply and nutritionally balanced model. The results suggested that the content of serum GLU by feeding diet Ⅲ was the highest, which extremely significantly higher than that of control group (P<0.01). The content of BUN in control group was significantly higher than those of another 3 groups (P<0.05), while the content of CHO in diet Ⅱ was significantly (P<0.05) or extremely significantly (P<0.01) higher than those of another 3 groups. The contents of TP, ALB, AST, ALT in diet Ⅱ was in the highest level, and significantly higher than that of control group (P<0.05), while the content of LDH in diet Ⅱ and Ⅲ were significantly lower than those of another 2 groups (P<0.05). The average daily gain of ewe in groups fed by diet Ⅱ and Ⅲ was significantly (P<0.05) or extremely significantly (P<0.01) higher than those of another 2 groups. Correspondingly, average daily gain of lambs in diet Ⅱ and Ⅲ groups was significantly higher than other two groups. Overall, there exists significant influence on serum biochemical indexes and weight of lambs by feeding diet Ⅱ and Ⅲ. However, in order to reduce the feeding cost and avoid the excess of energy and protein, feeding diet Ⅱ along with grazing is the optimal option.