1 材料与方法
1.1 试验材料
1.2 试验设计与饲养管理
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 | CK组 CK group | DP组 DP group | LP组 LP group | |
|---|---|---|---|---|
| 原料 Ingredients | ||||
| 棉籽壳 Cottonseed hull | 36.50 | 36.50 | 36.50 | |
| 苜蓿 Alfalfa | 23.50 | 23.50 | 23.50 | |
| 玉米 Corn | 12.00 | 16.70 | 16.70 | |
| 麸皮 Wheat bran | 12.02 | 12.67 | 12.67 | |
| 棉籽粕 Cottonseed meal | 10.60 | 5.25 | 5.25 | |
| 氯化钠 NaCl | 0.73 | 0.73 | 0.73 | |
| 碳酸钙 CaCO3 | 0.75 | 0.75 | 0.75 | |
| 磷酸氢钙 CaHPO4 | 0.90 | 0.90 | 0.90 | |
| 预混料 Premix1) | 3.00 | 3.00 | 3.00 | |
| 合计 Total | 100.00 | 100.00 | 100.00 | |
| 营养水平 Nutrient levels2) | ||||
| 干物质 DM | 84.09 | 84.25 | 83.28 | |
| 代谢能 ME/(MJ/kg) | 8.32 | 8.32 | 8.32 | |
| 过瘤胃赖氨酸 RPLys/(g/d) | 14.00 | |||
| 粗蛋白质 CP | 14.02 | 12.01 | 12.01 | |
| 粗灰分 Ash | 6.66 | 5.69 | 5.56 | |
| 粗脂肪 EE | 4.68 | 4.21 | 4.50 | |
| 酸性洗涤纤维 ADF | 31.33 | 30.58 | 30.74 | |
| 中性洗涤纤维 NDF | 51.06 | 51.99 | 51.58 | |
| 钙 Ca | 0.87 | 0.85 | 0.84 | |
| 磷 P | 0.46 | 0.48 | 0.50 | |
1)每千克预混料含有 One kilogram of premix contained the following:VA 55 000 IU,VD3 13 000 IU,VE 500 mg,Fe 1 300 mg,Se 10.8 mg,Mn 1 100 mg,Zn 1 500 mg,Cu 200 mg。 2)代谢能为计算值,其余为实测值。ME was a calculated value,while the others were measured values. |
1.3 消化代谢试验
1.4 样本采集
1.5 测定指标
1.5.1 生长性能
平均日增重(ADG)=(终末体重-初始体重)/饲养天数;
料重比(F/G)=DMI/ADG。
1.5.2 养分表观消化率
1.5.3 瘤胃发酵参数
1.5.4 氮代谢指标
粪氮(g/d)=[粪中CP含量(g/d)×每日排粪量(g/d)]/6.25;
尿氮(g/d)=[尿中CP含量(g/d)×每日排尿量(g/d)]/6.25;
总排出氮(g/d)=粪氮(g/d)+尿氮(g/d);
沉积氮(g/d)=食入氮(g/d)-[粪氮(g/d)+尿氮(g/d)];
氮生物学价值(%)=100×沉积氮(g/d)/[食入氮(g/d)-粪氮(g/d)];
氮利用率(%)=100×沉积氮(g/d)/食入氮(g/d)。
1.6 数据统计
2 结果
2.1 低蛋白质饲粮补加RPLys对多浪羊生长性能的影响
表2 低蛋白质饲粮补加RPLys对多浪羊生长性能的影响Table 2 Effects of low protein diet supplemented with RPLys on growth performance of Duolang sheep |
| 项目 Items | 组别 Groups | SEM | P值 P-value | ||
|---|---|---|---|---|---|
| CK | DP | LP | |||
| 初始体重 IBW/kg | 40.20 | 40.33 | 41.10 | 3.02 | 0.99 |
| 平均日增重 ADG/(g/d) | 201.28Bb | 197.16Bb | 224.45Aa | 0.04 | <0.01 |
| 干物质采食量 DMI/(kg/d) | 1.46 | 1.46 | 1.42 | 0.03 | 0.99 |
| 料重比 F/G | 7.25a | 7.40a | 6.34b | 0.20 | 0.03 |
同行数据肩标无字母或相同字母表示差异不显著(P>0.05),不同小写字母表示差异显著(P<0.05),不同大写字母表示差异极显著(P<0.01)。下表同。 | |
In the same row, values with no letter or the same letter superscripts mean no significant difference (P>0.05), while with different small letter superscripts mean significant difference (P<0.05), and with different capital letter superscripts mean extremely significant difference (P<0.01). The same as below. |
2.2 低蛋白质饲粮补加RPLys对多浪羊养分表观消化率的影响
表3 低蛋白质饲粮补加RPLys对多浪羊养分表观消化率的影响Table 3 Effects of low protein diet supplemented with RPLys on nutrient apparent digestibility of Duolang sheep % |
| 项目 Items | 组别 Groups | SEM | P值 P-value | ||
|---|---|---|---|---|---|
| CK | DP | LP | |||
| 干物质 DM | 65.10 | 64.84 | 67.43 | 0.01 | 0.42 |
| 粗蛋白质 CP | 65.70Bb | 61.25Cc | 68.06Aa | 0.01 | <0.01 |
| 中性洗涤纤维 NDF | 54.04 | 52.32 | 53.46 | 0.01 | 0.62 |
| 酸性洗涤纤维 ADF | 41.81 | 38.71 | 41.52 | 0.02 | 0.83 |
| 有机物 OM | 62.21Bb | 61.33Bb | 67.17Aa | 0.01 | <0.01 |
| 粗脂肪 EE | 84.92 | 88.56 | 87.44 | 0.01 | 0.27 |
2.3 低蛋白质饲粮补加RPLys对多浪羊瘤胃发酵参数的影响
表4 低蛋白质饲粮补加RPLys对多浪羊瘤胃发酵参数的影响Table 4 Effects of low protein diet supplemented with RPLys on rumen fermentation parameters of Duolang sheep |
| 项目 Items | 组别 Groups | SEM | P值 P-value | ||
|---|---|---|---|---|---|
| CK | DP | LP | |||
| pH | 6.45 | 6.40 | 6.49 | 0.12 | 0.96 |
| 氨态氮 NH3-N/(mg/dL) | 11.18 | 10.37 | 10.05 | 0.30 | 0.30 |
| 微生物蛋白 MCP/(mg/dL) | 32.69Bb | 36.88Aa | 37.44Aa | 0.58 | <0.01 |
| 乙酸 Acetic acid/(mmol/L) | 57.67Bb | 57.53Bb | 64.14Aa | 1.15 | <0.01 |
| 丙酸 Propionic acid/(mmol/L) | 18.08Bb | 19.98Bb | 24.49Aa | 1.01 | <0.01 |
| 丁酸 Butyric acid/(mmol/L) | 2.75 | 2.71 | 2.16 | 0.15 | 0.23 |
| 戊酸 Valeric acid/(mmol/L) | 1.70 | 2.41 | 1.62 | 0.36 | 0.69 |
| 乙酸/丙酸 Acetic acid/propionic acid | 2.51Aa | 2.28ABab | 2.06Bb | 0.07 | 0.01 |
| 总挥发性脂肪酸 TVFA/(mmol/L) | 85.07Bb | 88.02Bb | 99.00Aa | 2.16 | <0.01 |
2.4 低蛋白质饲粮补加RPLys对多浪羊氮代谢的影响
表5 低蛋白质饲粮补加RPLys对多浪羊氮代谢的影响Table 5 Effects of low protein diet supplemented with RPLys on nitrogen metabolism of Duolang sheep |
| 项目 Items | 组别 Groups | SEM | P值 P-value | ||
|---|---|---|---|---|---|
| CK | DP | LP | |||
| 食入氮 Intake nitrogen/(g/d) | 32.60 | 28.15 | 29.88 | 1.15 | 0.32 |
| 尿氮 Urine nitrogen/(g/d) | 6.99 | 5.82 | 5.54 | 0.33 | 0.18 |
| 粪氮 Fecal nitrogen/(g/d) | 15.21 | 12.66 | 13.66 | 0.48 | 0.07 |
| 总排出氮 Total excretion of nitrogen/(g/d) | 22.21 | 18.49 | 19.21 | 0.98 | 0.29 |
| 沉积氮 Retention nitrogen/(g/d) | 10.39 | 9.65 | 10.67 | 1.02 | 0.94 |
| 氮利用率 Utilization efficiency of nitrogen/% | 31.29 | 33.34 | 35.70 | 2.52 | 0.82 |
| 氮生物学价值 Biological value of nitrogen/% | 58.86 | 60.38 | 65.37 | 2.81 | 0.68 |

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