1 材料与方法
1.1 饲养试验
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 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Ⅰ | Ⅱ | Ⅲ | Ⅳ | Ⅴ | |||||||
| 原料 Ingredients | |||||||||||
| 玉米 Corn | 42.00 | 38.00 | 33.60 | 29.30 | 25.00 | ||||||
| 次粉 Wheat middlings | 8.00 | 8.00 | 8.00 | 8.00 | 8.00 | ||||||
| 麸皮 Wheat bran | 8.00 | 8.00 | 8.00 | 8.00 | 8.00 | ||||||
| 豆粕 Soybean meal | 1.00 | 5.00 | 9.40 | 13.70 | 18.00 | ||||||
| 苜蓿 Alfalfa | 15.00 | 15.00 | 15.00 | 15.00 | 15.00 | ||||||
| 花生秧 Peanut seedling | 15.00 | 15.00 | 15.00 | 15.00 | 15.00 | ||||||
| 稻壳粉 Rice husk powder | 8.00 | 8.00 | 8.00 | 8.00 | 8.00 | ||||||
| 赖氨酸 Lys | 0.20 | 0.20 | 0.20 | 0.20 | 0.20 | ||||||
| 大豆油 Soybean oil | 0.60 | 0.60 | 0.60 | 0.60 | 0.60 | ||||||
| 蛋氨酸 Met | 0.10 | 0.10 | 0.10 | 0.10 | 0.10 | ||||||
| 石粉 Limestone | 0.40 | 0.40 | 0.40 | 0.40 | 0.40 | ||||||
| 碳酸氢钠 NaHCO3 | 0.30 | 0.30 | 0.30 | 0.30 | 0.30 | ||||||
| 磷酸氢钙 CaHPO4 | 0.55 | 0.55 | 0.55 | 0.55 | 0.55 | ||||||
| 食盐 NaCl | 0.40 | 0.40 | 0.40 | 0.40 | 0.40 | ||||||
| 预混料 Premix1) | 0.45 | 0.45 | 0.45 | 0.45 | 0.45 | ||||||
| 合计 Total | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | ||||||
| 营养水平 Nutrient levels2) | |||||||||||
| 总能 GE/(MJ/kg) | 15.71 | 15.83 | 16.19 | 16.19 | 16.21 | ||||||
| 粗脂肪 EE | 3.07 | 3.05 | 2.99 | 2.94 | 2.93 | ||||||
| 粗蛋白质 CP | 9.98 | 11.46 | 13.02 | 14.43 | 16.06 | ||||||
| 粗纤维 CF | 14.41 | 15.53 | 15.85 | 15.78 | 17.27 | ||||||
| 酸性洗涤纤维 ADF | 20.54 | 21.62 | 22.13 | 22.91 | 23.86 | ||||||
| 中性洗涤纤维 NDF | 31.03 | 33.06 | 36.83 | 36.68 | 37.09 | ||||||
1)预混料为每千克饲粮提供(表2同) Premix provided the following per kg of diets (the same as Table 2):VA 8 100 IU,VB1 3 mg,VB2 8 mg,VB3 10.8 mg,VB5 34 mg,VB6 4 mg,VB7 0.13 mg,VB9 1.5 mg,VB12 0.02 mg,VD3 2 400 IU,VE 30 mg,VK 3 mg,Zn 70 mg,Fe 61 mg,Cu 8.3 mg,I 0.5 mg,Se 0.25 mg,Mn 60 mg。 |
1.2 无氮饲粮试验
表2 无氮饲粮组成及营养水平(风干基础)Table 2 Composition and nutrient levels of nitrogen-free diet (air-dry basis) % |
| 项目 Items | 含量 Content |
|---|---|
| 原料 Ingredients | |
| 玉米淀粉 Corn starch | 43.00 |
| 葡萄糖 Glucose | 6.50 |
| 蔗糖 Sucrose | 6.00 |
| 微晶纤维素 Microcrystalline cellulose | 25.00 |
| 稻壳粉 Rice husk powder | 10.00 |
| 大豆油 Soybean oil | 3.00 |
| 食盐 NaCl | 0.50 |
| 预混料 Premix1) | 3.00 |
| 石粉 Limestone | 1.00 |
| 磷酸氢钙 CaHPO4 | 2.00 |
| 合计 Total | 100.00 |
| 营养水平 Nutrient levels2) | |
| 总能 GE/(MJ/kg) | 15.50 |
| 粗纤维 CF | 15.22 |
| 粗蛋白质 CP | 0.62 |
| 粗脂肪 EE | 2.99 |
| 中性洗涤纤维 NDF | 38.65 |
| 酸性洗涤纤维 ADF | 22.31 |
1.3 消化代谢试验
1.4 饲养管理
1.5 样品采集
1.5.1 饲粮样品采集
1.5.2 粪样和尿样采集
1.6 测定指标与计算方法
1.6.1 生长性能指标
1.6.2 氮代谢指标
1.7 数据处理与统计分析
2 结果与分析
2.1 不同蛋白质水平对生长期德州驴氮代谢的影响
表3 试验前期不同蛋白质水平对德州驴氮代谢的影响Table 3 Effects of different protein levels during early phase of experiment on nitrogen utilization of Dezhou donkeys |
| 项目 Items | 食入氮 NI/(g/d) | 粪氮 FN/(g/d) | 可消化氮 DN/(g/d) | 尿氮 UN/(g/d) | 沉积氮 RN/(g/d) | 净蛋白质 利用率 NPU/% | 蛋白质生 物学价值 BV/% |
|---|---|---|---|---|---|---|---|
| 组别 Groups | |||||||
| Ⅰ | 55.00e | 15.51 | 39.49e | 23.48e | 16.02d | 55.69a | 68.85a |
| Ⅱ | 61.25d | 14.64 | 46.61d | 27.82d | 18.79c | 54.24a | 65.36b |
| Ⅲ | 68.94c | 15.62 | 53.32c | 30.92c | 22.40c | 54.01a | 63.76b |
| Ⅳ | 76.31b | 15.74 | 60.58b | 37.76b | 22.82b | 49.53b | 57.53c |
| Ⅴ | 88.93a | 15.08 | 73.85a | 47.02a | 26.83a | 47.00c | 52.93d |
| SEM | 2.118 | 0.201 | 2.131 | 1.481 | 0.689 | 0.637 | 0.988 |
| P值 P-value | <0.001 | 0.491 | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 |
表4 试验中期不同蛋白质水平对德州驴氮代谢的影响Table 4 Effects of different protein levels during middle phase of experiment on nitrogen utilization of Dezhou donkeys |
| 项目 Items | 食入氮 NI/(g/d) | 粪氮 FN/(g/d) | 可消化氮 DN/(g/d) | 尿氮 UN/(g/d) | 沉积氮 RN/(g/d) | 净蛋白质 利用率 NPU/% | 蛋白质生 物学价值 BV/% | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 组别 Groups | |||||||||||||||
| Ⅰ | 62.44e | 14.32b | 48.12e | 24.15e | 23.97c | 63.00a | 73.70a | ||||||||
| Ⅱ | 72.24d | 17.14a | 55.11d | 28.19d | 26.92b | 58.38b | 69.92b | ||||||||
| Ⅲ | 80.87c | 18.24a | 62.64c | 39.64c | 27.07b | 49.19c | 60.98c | ||||||||
| Ⅳ | 89.56b | 19.69a | 69.87b | 41.90b | 27.97b | 48.22c | 57.59d | ||||||||
| Ⅴ | 102.62a | 18.08a | 84.54a | 49.92a | 34.62a | 48.39c | 55.34e | ||||||||
| SEM | 2.377 | 0.490 | 2.455 | 1.609 | 0.769 | 1.157 | 1.241 | ||||||||
| P值 P-value | <0.001 | 0.002 | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 |
表5 试验后期不同蛋白质水平对德州驴氮代谢的影响Table 5 Effects of different protein levels during late phase of experiment on nitrogen utilization of Dezhou donkeys |
| 项目 Items | 食入氮 NI/(g/d) | 粪氮 FN/(g/d) | 可消化氮 DN/(g/d) | 尿氮 UN/(g/d) | 沉积氮 RN/(g/d) | 净蛋白质 利用率 NPU/% | 蛋白质生 物学价值 BV/% |
|---|---|---|---|---|---|---|---|
| 组别 Groups | |||||||
| Ⅰ | 78.50e | 20.81c | 57.69e | 32.82e | 24.87d | 53.46a | 66.04a |
| Ⅱ | 93.11d | 23.89bc | 71.57d | 38.15d | 32.36c | 50.95ab | 63.73b |
| Ⅲ | 107.19c | 26.15ab | 81.04c | 44.52c | 36.53b | 49.17ab | 61.40c |
| Ⅳ | 118.93b | 26.41ab | 92.52b | 50.93b | 41.59a | 49.94ab | 59.92d |
| Ⅴ | 128.62a | 28.49a | 100.12a | 56.23a | 43.90a | 46.90c | 57.24e |
| SEM | 3.068 | 0.743 | 2.877 | 1.447 | 1.397 | 0.700 | 0.596 |
| P值 P-value | <0.001 | 0.004 | <0.001 | <0.001 | <0.001 | 0.039 | <0.001 |
2.2 无氮饲粮试验的氮代谢分析
表6 无氮饲粮试验的氮代谢分析Table 6 Nitrogen metabolism analysis in nitrogen free diet experiment |
| 项目 Items | 体重 BW/kg | 代谢体重 W0.75/kg | 平均日 采食量 ADFI/kg | 食入氮 NI/(g/d) | 粪氮 FN/(g/d) | 尿氮 UN/(g/d) | 沉积氮 RN/(g/d) |
|---|---|---|---|---|---|---|---|
| A组 Group A | 139.63 | 40.62 | 1.8 | 1.71 | 4.00 | 8.60 | -10.89 |
| B组 Group B | 185.25 | 50.21 | 2.3 | 2.18 | 6.53 | 11.54 | -15.90 |
2.3 不同蛋白质水平对生长期德州驴生产性能的影响
表7 试验前期不同蛋白质水平对德州驴生长性能影响Table 7 Effects of different protein levels during early phase of experiment on growth performance of Dezhou donkeys |
| 项目 Items | 初始体重 IBW/kg | 结束体重 FBW/kg | 平均日采食量 ADFI/kg | 平均日增重 ADG/g | 料重比 F/G |
|---|---|---|---|---|---|
| 组别 Groups | |||||
| Ⅰ | 141.38 | 153.49 | 3.25 | 390.73d | 8.44a |
| Ⅱ | 141.00 | 154.39 | 3.25 | 431.86c | 7.57b |
| Ⅲ | 141.29 | 156.60 | 3.25 | 494.01b | 6.64c |
| Ⅳ | 141.75 | 158.54 | 3.25 | 541.53a | 6.01c |
| Ⅴ | 141.50 | 158.46 | 3.25 | 547.18a | 5.95c |
| SEM | 1.153 | 1.283 | 11.625 | 0.186 | |
| P值 P-value | 1.000 | 0.633 | <0.001 | <0.001 |
表8 试验中期不同蛋白质水平对德州驴生长性能的影响Table 8 Effects of different protein levels during middle phase of experiment on growth performance of Dezhou donkeys |
| 项目 Items | 初始体重 IBW/kg | 结束体重 FBW/kg | 平均日采食量 ADFI/kg | 平均日增重 ADG/g | 料重比 F/G |
|---|---|---|---|---|---|
| 组别 Groups | |||||
| Ⅰ | 151.38 | 164.19 | 4.00 | 427.08a | 9.62c |
| Ⅱ | 152.88 | 162.88 | 4.00 | 333.33b | 13.10b |
| Ⅲ | 154.64 | 165.29 | 4.00 | 354.76b | 15.76b |
| Ⅳ | 155.06 | 165.56 | 4.00 | 350.00b | 13.79b |
| Ⅴ | 155.38 | 163.69 | 4.00 | 277.08c | 16.26a |
| SEM | 1.409 | 1.376 | 8.889 | 0.335 | |
| P值 P-value | 0.894 | 0.975 | <0.001 | <0.001 |
表9 试验后期不同蛋白质水平对德州驴生长性能的影响Table 9 Effects of different protein levels during late phase of experiment on growth performance of Dezhou donkeys |
| 项目 Items | 初始体重 IBW/kg | 结束体重 FBW/kg | 平均日采食量 ADFI/kg | 平均日增重 ADG/g | 料重比 F/G |
|---|---|---|---|---|---|
| 组别 Groups | |||||
| Ⅰ | 166.13 | 189.19 | 4.47b | 591.35c | 7.57ab |
| Ⅱ | 163.63 | 189.69 | 4.83a | 668.27ab | 7.27ab |
| Ⅲ | 167.07 | 194.71 | 5.01a | 708.79a | 7.07c |
| Ⅳ | 167.25 | 188.06 | 4.78a | 533.66d | 8.97a |
| Ⅴ | 162.57 | 188.07 | 5.01a | 637.36b | 7.88b |
| SEM | 1.313 | 1.337 | 0.051 | 11.694 | 0.142 |
| P值 P-value | 0.753 | 0.483 | 0.002 | <0.001 | <0.001 |
