休牧舍饲饲粮中精补料替代混合料对泌乳期苏尼特羊体重、血液生化指标和矿物质含量的影响

Effect of increasing the proportion of supplementary concentrate on body weight,blood biochemical indices and mineral content in Sunit lactating ewes during rest grazing

试验研究休牧舍饲饲粮中精补料替代混合料对泌乳期苏尼特羊体重、血液生化指标和矿物质含量的影响。采用单因素完全随机试验设计,选择81只体重相近的经产泌乳前期苏尼特母羊,随机分为3组,每组3个重复,每个重复9只羊。对照组泌乳母羊按照原场方案进行休牧舍饲,精饲料由玉米和豆粕混合料构成,精粗比为20∶80,低精料组使用等量精补料替代对照组混合料,高精料组饲喂与低精料组相同的精补料,但精粗比提高到30∶70。3组粗饲料均由青干草与玉米秸秆构成。试验期30 d。结果显示,低精料组和高精料组母羊的血清甘油三酯(TG)含量均显著高于对照组,且高精料组血清TG含量显著高于低精料组(P<0.05)。低精料组和高精料组母羊的血清谷草转氨酶/谷丙转氨酶(AST/ALT)值、β-羟丁酸(D_(3)HB)和尿素氮(BUN)含量均显著低于对照组(P<0.05),低精料组母羊血清ALP活性显著低于高精料组和对照组(P<0.05)。高精料组母羊的血清Ca、Cu、Zn、Se含量显著高于对照组(P<0.05)。研究表明,用精料补充料等量替代苏尼特泌乳母羊玉米与大豆粕的混合料,能够增加泌乳前期苏尼特母羊对蛋白质的利用效率,改善母羊能量与钙磷营养状况的负平衡。进一步增加精补料比例可以促进母羊体重恢复,增加血清Ca、Cu、Zn、Se含量,降低BUN和D3HB浓度。

The experiment studied the effect of replacing mixture with supplementary concentrate on body weight, serum biochemical indexes and mineral content. The single factor randomized design was used in the experiment. Eighty-one healthy multiparous Sunit lactating ewes with similar body weight were selected and divided into three groups with three replicates in each group and night ewes in each replicate. The lactating ewes in control group were house-fed during rest grazing according to the original scheme. The supplementary concentrate was composed of corn and soybean meal mixture with the concentrate to roughage ratio of 20∶80. The low-precision feed group replaced the control group’s mixture with the same amount of refined feed. The lactating ewes in high-concentrate group was fed the same fine feed as the low-concentrate group, but the ratio of concentrate to roughage was increased to 30∶70. The three groups of roughage consisted of green hay and corn stalks. The trial period was 30 d. The results showed that the serum TG content of ewes in low-concentrate group and high-concentrate group was significantly higher than that of control group, and the serum TG content of high-concentrate group was significantly higher than that of low-concentrate group(P<0.05). The levels of serum AST/ALT, D3 HB and BUN of ewes in low-concentrate group and high-concentrate group were significantly lower than those in the control group(P<0.05). The serum ALP of ewes in low-concentrate group was significantly lower than that of high-concentrate group and the control group(P<0.05). The serum Ca, Cu, Zn and Se content of ewes in highconcentrate group were significantly higher than those of control group(P<0.05). The experiment indicates that replacement of mixture of corn and soybean meal by the same level of supplementary concentrate can increases the utilization efficiency of protein, and improve the negative balance of energy and nutritional status of calcium and phosphorus in ewes during early lactation period. Further increasing proportion of supplementary concentrate can promote the weight recovery of ewes, increase the levels of Ca, Cu, Zn, Se in serum, and decrase the concentrations of BUN and D3 HB during early lactation period.