1 材料与方法
1.1 试验时间和地点
1.2 试验设计
表1 饲粮组成及营养水平(干物质基础)Table 1 Composition and nutrient levels of diets (DM basis) % |
| 项目 Items | 组别Groups | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| A | B | C | D | E | |||||||
| 原料Ingredients | |||||||||||
| 麦秸Wheat straw | 27.15 | 26.14 | 25.36 | 24.88 | 24.40 | ||||||
| 啤酒糟Brewer’s grains | 5.00 | 8.00 | 10.00 | 12.00 | 14.00 | ||||||
| 玉米Corn | 56.16 | 50.04 | 42.25 | 39.29 | 34.72 | ||||||
| 麦麸Wheat bran | 8.00 | 12.00 | 18.00 | 18.00 | 20.00 | ||||||
| 豆粕Soybean meal | 0.76 | 0.96 | 1.50 | 3.01 | 4.16 | ||||||
| 小苏打NaHCO3 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | ||||||
| 食盐NaCl | 0.50 | 0.50 | 0.50 | 0.50 | 0.50 | ||||||
| 石粉Limestone | 0.30 | 0.30 | 0.10 | 0.13 | 0.22 | ||||||
| 磷酸氢钙CaPHO4 | 0.13 | 0.06 | 0.29 | 0.19 | |||||||
| 预混料Premix1) | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | ||||||
| 合计Total | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | ||||||
| 营养水平Nutrient levels2) | |||||||||||
| 综合净能NEmf/(MJ/kg) | 6.12 | 6.12 | 6.12 | 6.12 | 6.12 | ||||||
| 粗蛋白质CP | 9.53 | 10.53 | 11.53 | 12.53 | 13.53 | ||||||
| 钙Ca | 0.50 | 0.50 | 0.50 | 0.50 | 0.50 | ||||||
| 磷P | 0.33 | 0.33 | 0.33 | 0.33 | 0.33 | ||||||
| 中性洗涤纤维NDF | 31.73 | 33.05 | 34.79 | 35.13 | 36.01 | ||||||
| 酸性洗涤纤维ADF | 18.77 | 19.32 | 20.01 | 20.30 | 20.78 | ||||||
1)每千克预混料含有 Per kilogram of premix contained the following: VD 320 000 IU,VA 150 000 IU,VE 4 000 IU,Fe 5 200 mg,Mn 1 600 mg,Zn 3 000 mg,Cu 700 mg,I 40 mg,Se 15 mg,Co 15 mg,Ca 150 g,P 40 g。 2) 综合净能为计算值,其他为实测值。NEmf was a calculated value,while the others were measured values. |
1.3 饲养管理
1.4 消化代谢试验
1.5 检测指标与方法
1.5.1 生长性能的测定
1.5.2 饲粮样品检测指标
1.5.3 蛋白质代谢指标的测定
1.6 计算公式
1.7 数据统计与分析
2 结果
2.1 饲粮不同CP水平对500~550 kg西门塔尔杂交牛生长性能的影响
表2 饲粮CP水平对500~550 kg西门塔尔杂交牛生长性能的影响Table 2 Effects of dietary CP levels on growth performance of 500 to 550 kg Simmental hybrid bulls |
| 项目 Items | 组别Groups | SEM | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| A | B | C | D | E组 | 处理 Treatment | 线性 Linear | 二次 Quadratic | ||
| 初始体重IBW/kg | 493.6 | 498.6 | 503.0 | 497.8 | 499.0 | 8.20 | 0.348 | 0.838 | 0.916 |
| 终末体重FBW/kg | 535.4 | 548.0 | 553.4 | 559.0 | 541.6 | 8.88 | 0.284 | 0.753 | 0.659 |
| 平均日增重 ADG/(kg/d) | 0.76b | 0.90ab | 0.92ab | 1.11a | 0.77b | 0.06 | 0.042 | 0.583 | 0.047 |
| 平均干物质日采食量 ADMI/(kg/d) | 9.26c | 10.31a | 10.22ab | 9.80ab | 9.99ab | 0.10 | 0.013 | 0.073 | 0.002 |
| 料重比F/G | 12.74ab | 13.06ab | 12.41ab | 8.98b | 15.35a | 0.95 | 0.044 | 0.876 | 0.043 |
同行数据肩标不同小写字母表示差异显著(P<0.05)。下表同。 | |
In the same row, values with different small letter superscripts mean significant difference (P<0.05). The same as below. |
2.2 饲粮不同CP水平对500~550 kg西门塔尔杂交牛蛋白质代谢的影响
表3 饲粮CP水平对500~550 kg西门塔尔杂交牛蛋白质代谢的影响Table 3 Effects of dietary CP levels on protein metabolism of 500 to 550 kg Simmental hybrid bulls |
| 项目 Items | 组别Groups | SEM | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| A | B | C | D | E | 处理 Treatment | 线性 Linear | 二次 Quadratic | ||
| 进食氮 Feeding nitrogen/(g/d) | 127.76c | 143.86b | 147.97ab | 139.93b | 154.25a | 2.03 | 0.043 | 0.001 | 0.099 |
| 粪氮排泄量 Fecal nitrogen excretion/(g/d) | 34.10bc | 37.23a | 35.51ab | 32.64c | 36.85a | 0.41 | 0.018 | 0.001 | 0.143 |
| 尿氮排泄量 Urinary nitrogen excretion/(g/d) | 52.39bc | 55.37a | 53.74ab | 50.69c | 55.56a | 1.23 | 0.026 | 0.001 | 0.684 |
| 沉积氮 Deposited nitrogen/(g/d) | 40.27d | 50.59c | 58.72ab | 56.25b | 62.40a | 1.55 | 0.030 | 0.001 | 0.004 |
| 粗蛋白质消化率 CP digestibility/% | 71.10 | 73.84 | 75.88 | 74.94 | 74.73 | 0.30 | 0.233 | 0.251 | 0.279 |
| 粗蛋白质沉积率 CP deposition rate/% | 31.75d | 35.33c | 39.68b | 40.45a | 40.09b | 1.55 | 0.012 | 0.001 | 0.010 |
