1 材料与方法
1.1 试验材料
表1 甘草渣和草坪草的营养成分含量(风干基础)Table 1 Nutrient contents of licorice residue and lawn grass (air-dry basis) % |
| 项目 Items | 干物质 DM | 粗蛋白质 CP | 中性洗涤纤维 NDF | 酸性洗涤纤维 ADF | 粗脂肪 EE | 钙 Ca | 总磷 TP |
|---|---|---|---|---|---|---|---|
| 甘草渣Licorice residue | 87.53 | 7.77 | 68.17 | 37.07 | 3.99 | 0.25 | 0.14 |
| 草坪草Lawn grass | 93.20 | 8.57 | 61.79 | 33.90 | 2.60 | 0.29 | 0.16 |
1.2 试验设计
表2 试验饲粮组成及营养水平(风干基础)Table 2 Composition and nutrient levels of experimental diets (air-dry basis) % |
| 项目 Items | 组别Groups | ||||
|---|---|---|---|---|---|
| 0%LR | 15%LR | 30%LR | 45%LR | 60%LR | |
| 原料Ingredients | |||||
| 甘草渣Licorice residue | 3.00 | 6.00 | 9.00 | 12.00 | |
| 草坪草Lawn grass | 20.00 | 17.00 | 14.00 | 11.00 | 8.00 |
| 苜蓿草粉Alfalfa meal | 5.00 | 5.00 | 5.00 | 5.00 | 5.00 |
| 玉米Corn | 26.00 | 26.00 | 26.00 | 26.00 | 26.00 |
| 磷酸氢钙CaHPO4 | 0.80 | 0.80 | 0.80 | 0.80 | 0.80 |
| 米糠粕Rice bran | 17.70 | 17.70 | 17.70 | 17.70 | 17.70 |
| 麸皮Bran | 16.00 | 16.00 | 16.00 | 16.00 | 16.00 |
| 豆粕Soybean meal | 11.00 | 11.00 | 11.00 | 11.00 | 11.00 |
| 食盐NaCl | 0.50 | 0.50 | 0.50 | 0.50 | 0.50 |
| 预混料Premix1) | 3.00 | 3.00 | 3.00 | 3.00 | 3.00 |
| 合计Total | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 |
| 营养水平Nutrient levels2) | |||||
| 消化能DE/(MJ/kg) | 9.73 | 9.72 | 9.71 | 9.70 | 9.69 |
| 粗蛋白质CP | 14.75 | 14.73 | 14.70 | 14.68 | 14.66 |
| 粗纤维CF | 10.28 | 10.29 | 10.30 | 10.31 | 10.32 |
| 中性洗涤纤维NDF | 28.59 | 28.78 | 28.97 | 29.16 | 29.36 |
| 酸性洗涤纤维ADF | 13.78 | 13.87 | 13.97 | 14.06 | 14.16 |
| 酸性洗涤木质素ADL | 4.14 | 4.17 | 4.20 | 4.24 | 4.27 |
| 粗灰分Ash | 5.42 | 5.40 | 5.37 | 5.34 | 5.32 |
| 粗脂肪EE | 2.77 | 2.81 | 2.86 | 2.90 | 2.94 |
| 钙Ca | 0.88 | 0.86 | 0.84 | 0.82 | 0.81 |
| 总磷TP | 0.47 | 0.47 | 0.47 | 0.48 | 0.48 |
| 赖氨酸Lys | 0.81 | 0.80 | 0.79 | 0.79 | 0.78 |
| 蛋氨酸+胱氨酸Met+Cys | 0.52 | 0.51 | 0.51 | 0.50 | 0.50 |
1)预混料为每千克饲粮提供 Premix provided the following per kg of diets:VA 8 000 IU,VD3 1 500 IU,VE 50 mg,VK3 2 mg,VB2 3 mg,Fe 50 mg,Mn 10 mg,Se 0.05 mg,Cu 10 mg,Zn 50 mg。 2)消化能为计算值,其他均为实测值。DE was a calculated value, while the others were measured values. |
1.3 饲养管理
1.4 样品采集与制备
1.5 测定指标与测定方法
1.5.1 生长性能
1.5.2 肠道形态
1.5.3 肠道消化酶活性
1.5.4 胃肠道pH
1.5.5 免疫功能指标
1.5.5.1 器官重量与器官指数
1.5.5.2 血清免疫球蛋白含量
1.6 统计分析
2 结果与分析
2.1 甘草渣替代不同比例草坪草对肉兔生长性能的影响
表3 甘草渣替代不同比例草坪草对肉兔生长性能的影响Table 3 Effects of replacing different proportions of lawn grass with licorice residue on growth performance of meat rabbits |
| 项目 Items | 组别Groups | SEM | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 0%LR | 15%LR | 30%LR | 45%LR | 60%LR | 处理 Treatment | 线性 Linear | 二次 Quadratic | ||
| 初始体重IBW/g | 1 022.50 | 997.86 | 1 027.86 | 1 070.00 | 1 027.86 | 10.969 | 0.357 | 0.290 | 0.803 |
| 终末体重FBW/g | 2 544.55bc | 2 837.86a | 2 695.00b | 2 440.71c | 2 512.86c | 34.956 | <0.001 | 0.020 | 0.019 |
| 平均日采食量ADFI/(g/d) | 131.08b | 138.03a | 137.82a | 134.87ab | 133.68b | 0.702 | 0.003 | 0.620 | <0.001 |
| 平均日增重ADG/(g/d) | 30.44bc | 36.80a | 33.34ab | 27.96c | 29.70bc | 0.754 | <0.001 | 0.015 | 0.026 |
| 料重比F/G | 4.13b | 3.70b | 4.12b | 4.63a | 4.75a | 0.094 | <0.001 | <0.001 | 0.058 |
| 腹泻率Diarrhea rate/% | 12.50 | 4.17 | 12.50 | 16.67 | 16.67 | 0.683 | |||
| 死亡率Mortality/% | 0.00 | 0.00 | 4.17 | 0.00 | 8.33 | 0.242 | |||
同行数据肩标相同字母或无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)。下表同。 | |
Within a row, values with the same lowercase letter or no letter superscripts indicated no significant difference (P>0.05), while those with different lowercase letter superscripts indicated significant difference (P<0.05). The same as below. |
2.2 甘草渣替代不同比例草坪草对肉兔肠道形态的影响
表4 甘草渣替代不同比例草坪草对肉兔肠道形态的影响Table 4 Effects of replacing different proportions of lawn grass with licorice residue on intestinal morphology of meat rabbits |
| 项目 Items | 组别Groups | SEM | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 0%LR | 15%LR | 30%LR | 45%LR | 60%LR | 处理 Treatment | 线性 Linear | 二次 Quadratic | ||
| 十二指肠Duodenum | |||||||||
| 绒毛高度VH/μm | 956.67 | 966.67 | 990.00 | 843.33 | 1 150.00 | 36.014 | 0.081 | 0.271 | 0.097 |
| 绒毛宽度VW/μm | 108.33a | 115.33a | 109.33a | 90.18b | 113.33a | 3.127 | 0.049 | 0.600 | 0.525 |
| 隐窝深度CD/μm | 167.33 | 154.00 | 151.67 | 151.00 | 131.33 | 5.505 | 0.393 | 0.086 | 0.774 |
| 绒隐比VH/CD | 5.70 | 6.29 | 6.86 | 5.71 | 8.83 | 0.433 | 0.099 | 0.071 | 0.219 |
| 肌层厚度MT/μm | 89.07c | 151.14a | 112.64b | 113.24b | 113.19b | 5.972 | 0.002 | 0.056 | <0.001 |
| 空肠Jejunum | |||||||||
| 绒毛高度VH/μm | 746.67cd | 827.33bc | 695.33d | 926.33ab | 947.00a | 29.382 | 0.002 | <0.001 | 0.419 |
| 绒毛宽度VW/μm | 77.88bc | 73.48c | 84.78bc | 92.09ab | 105.87a | 3.539 | 0.005 | 0.002 | 0.033 |
| 隐窝深度CD/μm | 110.97ab | 114.59ab | 134.42a | 88.87b | 121.67a | 4.989 | 0.025 | 0.357 | 0.674 |
| 绒隐比VH/CD | 6.82bc | 7.29bc | 5.28c | 10.50a | 7.90b | 0.531 | 0.006 | 0.008 | 0.736 |
| 肌层厚度MT/μm | 82.32b | 132.45a | 144.74a | 103.46b | 103.16b | 6.525 | <0.001 | 0.986 | <0.001 |
| 回肠Ileum | |||||||||
| 绒毛高度VH/μm | 622.75c | 807.88b | 646.66c | 926.29b | 1 116.67a | 52.061 | <0.001 | <0.001 | 0.125 |
| 绒毛宽度VW/μm | 95.33a | 68.80b | 73.89b | 87.01a | 65.75b | 3.308 | <0.001 | 0.003 | 0.113 |
| 隐窝深度CD/μm | 106.45b | 152.77a | 118.66b | 127.34b | 122.25b | 4.973 | 0.016 | 0.121 | 0.007 |
| 绒隐比VH/CD | 5.86b | 5.33b | 5.55b | 7.29b | 9.26a | 0.450 | 0.004 | <0.001 | 0.011 |
| 肌层厚度MT/μm | 141.93ab | 126.99bc | 121.67c | 153.08a | 139.25ab | 3.583 | 0.012 | 0.148 | 0.118 |
2.3 甘草渣替代不同比例草坪草对肉兔肠道消化酶活性及胃肠道pH的影响
2.3.1 肠道消化酶活性
表5 甘草渣替代不同比例草坪草对肉兔肠道消化酶活性的影响Table 5 Effects of replacing different proportions of lawn grass with licorice residue on intestinal digestive enzyme activities of meat rabbits U/g |
| 项目 Items | 组别Groups | SEM | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 0%LR | 15%LR | 30%LR | 45%LR | 60%LR | 处理 Treatment | 线性 Linear | 二次 Quadratic | ||
| 十二指肠Duodenum | |||||||||
| 脂肪酶LPS | 118.20c | 183.78a | 161.87ab | 143.18bc | 148.61b | 52.774 | 0.002 | <0.001 | 0.878 |
| 胰蛋白酶Trypsin | 41.28c | 65.52a | 47.80bc | 57.63ab | 58.52a | 2.586 | 0.002 | 0.025 | 0.140 |
| α-淀粉酶α-AMY | 58.64c | 111.41a | 87.02ab | 62.39bc | 78.76bc | 5.937 | 0.007 | 0.741 | 0.038 |
| 空肠Jejunum | |||||||||
| 脂肪酶LPS | 99.45b | 128.04a | 86.98b | 106.30ab | 95.23b | 4.717 | 0.032 | 0.242 | 0.524 |
| 胰蛋白酶Trypsin | 15.04d | 37.49a | 30.56b | 16.86d | 24.75c | 2.263 | <0.001 | 0.380 | <0.001 |
| α-淀粉酶α-AMY | 46.46 | 60.14 | 51.54 | 50.37 | 48.09 | 2.265 | 0.390 | 0.687 | 0.217 |
| 回肠Ileum | |||||||||
| 脂肪酶LPS | 55.34b | 52.91b | 75.94a | 65.24ab | 62.96b | 2.578 | 0.009 | 0.038 | 0.035 |
| 胰蛋白酶Trypsin | 8.78b | 15.81a | 13.94a | 12.82a | 13.55a | 0.708 | 0.003 | 0.045 | 0.006 |
| α-淀粉酶α-AMY | 29.28b | 35.35a | 29.16b | 29.05b | 30.35b | 0.777 | 0.014 | 0.282 | 0.444 |
| 盲肠Caecum | |||||||||
| 脂肪酶LPS | 37.22 | 44.45 | 38.89 | 38.36 | 34.64 | 1.437 | 0.303 | 0.269 | 0.170 |
| 胰蛋白酶Trypsin | 6.15c | 9.80b | 10.46ab | 13.63a | 12.82ab | 0.808 | 0.004 | <0.001 | 0.135 |
| α-淀粉酶α-AMY | 10.48 | 17.00 | 11.48 | 10.45 | 15.12 | 1.156 | 0.265 | 0.728 | 0.932 |
| 纤维素酶Cellulase | 46.12c | 53.94bc | 56.37abc | 58.38ab | 66.16a | 2.205 | 0.033 | 0.003 | 0.972 |
2.3.2 胃肠道pH
表6 甘草渣替代不同比例草坪草对肉兔胃肠道pH的影响Table 6 Effects of replacing different proportions of lawn grass with licorice residue on pH of gastrointestinal tract of meat rabbits |
| 项目 Items | 组别Groups | SEM | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 0%LR | 15%LR | 30%LR | 45%LR | 60%LR | 处理 Treatment | 线性 Linear | 二次 Quadratic | ||
| 胃Stomach | 1.83 | 1.76 | 1.82 | 1.82 | 1.89 | 0.037 | 0.877 | 0.520 | 0.497 |
| 十二指肠Duodenum | 6.03b | 6.23ab | 5.80b | 6.32ab | 6.61a | 0.089 | 0.043 | 0.040 | 0.110 |
| 空肠Jejunum | 6.51b | 6.71b | 6.66b | 7.09a | 6.74ab | 0.059 | 0.026 | 0.033 | 0.193 |
| 回肠Ileum | 7.03ab | 7.14ab | 7.21a | 6.71c | 6.92bc | 0.042 | <0.001 | 0.008 | 0.198 |
| 盲肠Caecum | 6.54b | 6.73b | 6.43b | 7.34a | 7.37a | 0.074 | <0.001 | <0.001 | 0.029 |
2.4 甘草渣替代不同比例草坪草对肉兔免疫功能的影响
2.4.1 器官重量和器官指数
表7 甘草渣替代不同比例草坪草对肉兔器官重量和器官指数的影响Table 7 Effects of replacing different proportions of lawn grass with licorice residue on organ weight and organ indexes of meat rabbits |
| 项目 Items | 组别Groups | SEM | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 0%LR | 15%LR | 30%LR | 45%LR | 60%LR | 处理 Treatment | 线性 Linear | 二次 Quadratic | ||
| 器官重量Organ weight/g | |||||||||
| 心脏Heart | 10.93 | 8.96 | 10.04 | 9.20 | 8.22 | 0.513 | 0.566 | 0.197 | 0.991 |
| 肝脏Liver | 76.65c | 110.18a | 93.23b | 88.77bc | 91.13b | 3.318 | 0.005 | 0.597 | 0.012 |
| 肾脏Kidney | 20.31 | 18.17 | 17.12 | 16.84 | 17.47 | 0.490 | 0.149 | 0.042 | 0.106 |
| 脾脏Spleen | 1.52 | 1.48 | 1.55 | 1.35 | 1.41 | 0.071 | 0.929 | 0.539 | 0.927 |
| 胸腺Thymus | 5.96 | 6.12 | 3.94 | 4.92 | 4.25 | 0.323 | 0.084 | 0.032 | 0.507 |
| 蚓突Appendix | 2.04 | 1.57 | 1.38 | 1.69 | 1.48 | 0.114 | 0.442 | 0.240 | 0.301 |
| 圆小囊Round sacs | 4.26 | 3.78 | 3.98 | 4.14 | 4.35 | 0.203 | 0.936 | 0.745 | 0.504 |
| 肺脏Lung | 17.40 | 18.53 | 20.42 | 19.67 | 22.46 | 1.375 | 0.861 | 0.323 | 0.959 |
| 器官指数Organ indexes/(g/kg) | |||||||||
| 心脏Heart | 3.96 | 2.96 | 3.53 | 3.35 | 3.20 | 0.177 | 0.513 | 0.399 | 0.539 |
| 肝脏Liver | 27.68b | 36.39a | 33.02ab | 32.34ab | 35.58a | 1.044 | 0.034 | 0.055 | 0.226 |
| 肾脏Kidney | 7.34 | 6.01 | 6.05 | 6.12 | 6.82 | 0.194 | 0.087 | 0.421 | 0.012 |
| 脾脏Spleen | 0.55 | 0.49 | 0.54 | 0.50 | 0.55 | 0.026 | 0.930 | 0.971 | 0.627 |
| 胸腺Thymus | 2.16 | 2.02 | 1.39 | 1.79 | 1.67 | 0.110 | 0.193 | 0.112 | 0.229 |
| 蚓突Appendix | 0.74 | 0.52 | 0.49 | 0.61 | 0.58 | 0.044 | 0.430 | 0.451 | 0.172 |
| 圆小囊Round sacs | 1.55 | 1.25 | 1.41 | 1.49 | 1.70 | 0.083 | 0.580 | 0.385 | 0.222 |
| 肺脏Lung | 6.27 | 6.18 | 7.19 | 7.17 | 8.84 | 0.551 | 0.619 | 0.164 | 0.619 |
2.4.2 血清免疫球蛋白含量
表8 甘草渣替代不同比例草坪草对肉兔血清免疫球蛋白含量的影响Table 8 Effects of replacing different proportions of lawn grass with licorice residue on immunoglobulin contents in serum of meat rabbits g/L |
| 项目 Items | 组别Groups | SEM | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 0%LR | 15%LR | 30%LR | 45%LR | 60%LR | 处理 Treatment | 线性 Linear | 二次 Quadratic | ||
| 免疫球蛋白A IgA | 0.26c | 0.32bc | 0.44a | 0.42a | 0.38ab | 0.021 | 0.004 | 0.003 | 0.005 |
| 免疫球蛋白G IgG | 5.89 | 10.47 | 11.28 | 9.12 | 9.59 | 0.763 | 0.207 | 0.242 | 0.081 |
| 免疫球蛋白M IgM | 0.62b | 0.94a | 1.01a | 0.87a | 0.93a | 0.042 | 0.010 | 0.015 | 0.012 |
