养殖与饲料

[目的]研究青贮与黄贮玉米秸秆不同配比对西门塔尔牛育肥效果的影响，优化粗饲料组合方案，提高秸秆资源利用效率。[方法]采用正交试验设计，将54头14～29月龄西门塔尔公牛按初始体重（200、300、500 kg）分为A、B、C三组，每组18头；每组再按玉米秸秆青贮与黄贮配比（2∶1、3∶1、4∶1）随机分为a、b、c三亚组，每亚组6头。粗饲料占日粮60%，精饲料40%，试验周期91 d，测定各组日增重、料重比、饲料报酬及单位增重成本。[结果]初重500 kg、配比4∶1的Cc组日增重最高（1 499 g），显著高于其他组（P<0.05），料重比最低（8.16），单位增重成本最低（13.89元/kg）；而初重200 kg组在相同配比下单位增重较低但饲料效率较高。[结论]青贮与黄贮配比显著影响西门塔尔牛育肥效果，其中4∶1配比在500 kg初始体重条件下综合效益最优。

[Objectives]The effects of different ratios of silage to yellow-stored maize straw on the fattening performance of Simmental cattle were studied to optimize the combination scheme of roughage and improve the utilization efficiency of straw resource. [Methods]54 Simmental bulls aged 14-29 months were divided into 3 groups named as group A, B, and C based on their initial weight including 200 kg, 300 kg, and 500kg, with 18 bulls in each group to conduct an orthogonal experimental design. Each group was further randomly divided into three subgroups including a, b, and c based on the ratios of silage to yellow-stored maize straw including 2∶1, 3∶1, and 4∶1, with 6 bulls in each subgroup. Roughage and refined feed accounted for 60%and 40% of the diet. The experiment lasted 91 days. The daily weight gain, feed-to-gain ratio, feed reward, and cost per unit weight gain in each group were measured.[Results]The daily weight gain in the Cc group with an initial weight of 500 kg and a 4∶1 ratio of silage to yellow-stored maize straw was the highest(1 499 g), significantly higher than that in other groups(P<0.05), with the lowest feed to gain ratio(8.16) and the lowest cost per unit weight gain(13.89 yuan/kg). The group with an initial weight of 200 kg had lower weight gain and higher utilization efficiency of feed under the same ratio.[Conclusions]The ratio of silage to yellow-stored maize straw significantly affected the fattening performance of Simmental cattle, and the 4 ∶1 ratio had the best comprehensive benefit under the condition of 500 kg body weight. It can be recommended as a large-scale fattening scheme for Simmental cattle.