1 材料与方法
1.1 试验设计
表1 试验饲粮组成及营养水平(风干基础)Table 1 Composition and nutrient levels of experimental diets (air-dry basis) % |
| 项目 Items | 组别Groups | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| A | B | C | D | E | |||||||
| 原料Ingredients | |||||||||||
| 玉米Corn | 30.0 | 31.0 | 32.0 | 33.0 | 34.0 | ||||||
| 棉籽粕Cottonseed meal | 3.0 | 3.0 | 3.0 | 3.0 | 3.0 | ||||||
| 豆粕Soybean meal | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | ||||||
| 小麦麸Wheat bran | 8.0 | 8.0 | 8.0 | 8.0 | 8.0 | ||||||
| 玉米秸秆Corn straw | 23.4 | 22.4 | 21.4 | 20.4 | 19.4 | ||||||
| 玉米青贮Corn silage | 20.0 | 20.0 | 20.0 | 20.0 | 20.0 | ||||||
| 食盐NaCl | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | ||||||
| 预混料Premix1) | 3.0 | 3.0 | 3.0 | 3.0 | 3.0 | ||||||
| 合计Total | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | ||||||
| 营养水平Nutrient levels2) | |||||||||||
| 生长净能NEg/(MJ/kg) | 5.26 | 5.31 | 5.36 | 5.41 | 5.46 | ||||||
| 干物质DM | 51.20 | 51.20 | 51.20 | 51.20 | 51.20 | ||||||
| 粗蛋白质CP | 13.46 | 13.46 | 13.46 | 13.46 | 13.46 | ||||||
| 粗脂肪EE | 4.38 | 4.41 | 4.43 | 4.45 | 4.47 | ||||||
| 酸性洗涤纤维ADF | 22.40 | 21.90 | 21.10 | 20.30 | 19.60 | ||||||
| 中性洗涤纤维NDF | 28.90 | 28.10 | 27.40 | 26.80 | 26.10 | ||||||
| 钙Ca | 0.69 | 0.69 | 0.69 | 0.69 | 0.69 | ||||||
| 磷P | 0.44 | 0.44 | 0.44 | 0.44 | 0.44 | ||||||
1)每千克预混料含有 One kg of the premix contained the following:Fe 1 400 mg,Cu 1 200 mg,Mn 2 400 mg,Zn 5 500 mg; Se 40 mg,Co 30 mg,I 90 mg,VA 900 000 IU,VD 700 000 IU,VE 9 000 IU。 |
1.2 补充数据获取及筛选
表2 补充数据收集特征Table 2 Collection characteristics of supplementary data |
| 项目 Items | 文献数目 Literature number | 总文献数目 Total literature number | 平均值 Mean | 最大值 Maximum | 最小值 Minimum |
|---|---|---|---|---|---|
| 初始体重150~300 kg IBW 150~300 kg | 16 | 87 | 236.4 | 289 | 186 |
| 初始体重300~500 kg IBW 300~500 kg | 21 | 98 | 403.6 | 463 | 311 |
| 初始体重>500 kg IBW>500 kg | 14 | 80 | 532.4 | 564 | 503 |
| 代谢体重BW0.75/kg | 41 | 207 | 82.2 | 112.6 | 47.7 |
| 平均日增重ADG/kg | 51 | 265 | 1.14 | 1.37 | 0.81 |
| 生长净能NEg/(MJ/kg) | 36 | 164 | 40.38 | 46.74 | 26.91 |
| 干物质采食量DMI/kg | 51 | 265 | 8.10 | 9.17 | 4.62 |
| 饲料转化率FCR | 51 | 265 | 7.17 | 8.61 | 4.90 |
1.3 数据统计分析
2 结果与分析
2.1 饲料能量水平及DMI对育肥全期ADG和FCR的影响
图1 增重净能矫正模型对育肥全期肉牛ADG和FCR的影响ADG:平均日增重 average daily gain;FCR:饲料转化率 feed conversion ratio;Act:实测值 actual measured value;Pre:预测模型 predictive model;Adj:矫正后预测模型 adjusted predictive model。下图同 the same as below。 Fig.1 Impacts of net energy adjusted model on ADG and FCR of beef cattle during fattening stage |
