1 材料与方法
1.1 试验设计
表1 饲粮组成及营养水平(风干基础)Table 1 Composition and nutrient levels of diets(air-dry basis) % |
| 原料 Ingredients | 含量 Content | 营养水平 Nutrient levels2) | 含量 Content | |
|---|---|---|---|---|
| 玉米Corn | 25.0 | 消化能DE/(MJ/kg) | 9.90 | |
| 豆粕Soybean meal | 17.0 | 粗蛋白质CP | 16.26 | |
| 小麦麸皮Wheat bran | 11.0 | 中性洗涤纤维NDF | 31.27 | |
| 次粉Wheat middling | 10.0 | 酸性洗涤纤维ADF | 20.39 | |
| 苜蓿草粉Alfalfa meal | 8.0 | 酸性洗涤木质素ADL | 6.26 | |
| 花生秧Peanut vine | 8.0 | 粗脂肪EE | 2.55 | |
| 花生壳Peanut shell | 19.0 | 钙Ca | 0.84 | |
| 磷酸氢钙CaHPO4 | 0.5 | 总磷TP | 0.44 | |
| 碳酸钙CaCO3 | 0.5 | 赖氨酸Lys | 0.79 | |
| 预混料Premix1) | 1.0 | 蛋氨酸+半胱氨酸Met+Cys | 0.56 | |
| 合计Total | 100.0 |
1)预混料为每千克饲粮提供 Premix provided the following per kg of the diet: VA 10 000 IU,VD3 1 500 IU, VE 50 mg,VK3 3.0 mg,硫胺素 thiamine 5 mg,核黄素 riboflavin 10 mg,泛酸 pantothenic acid 20 mg,烟酸 nicotinic acid 50 mg,Fe 100 mg,Zn 30 mg,Cu 20 mg,Mn 30 mg,Se 0.05 mg,胆碱 choline 400 mg,食盐 NaCl 5 g,赖氨酸 Lys 1 g,蛋氨酸 Met 1 g,其余由杂粕载体补足 the rest was miscellaneous meal carrier complement。 2)消化能为计算值,其余均为实测值。DE was a calculated value, while the others were measured values. |
1.2 检测指标
1.2.1 生产性能指标的测定
1.2.2 肌肉物理性状的测定
1.2.3 肌肉营养成分的测定
1.2.4 肌肉黑色素和肌红蛋白含量的测定
1.2.5 肌肉脂肪酸含量的测定
1.2.6 肌肉核苷酸含量的测定
1.2.7 肌肉挥发性物质含量的测定
1.3 统计分析
2 结果
2.1 不同屠宰日龄莱芜黑兔的生产性能
表2 不同屠宰日龄莱芜黑兔的生产性能Table 2 Production performance of Laiwu black rabbits at different slaughter ages |
| 项目 Items | 屠宰日龄Slaughter ages | SEM | P值 P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 75 | 84 | 115 | |||||||
| 初体重 Initial body weight/g | 994.00 ±128.51 | 978.00 ±109.52 | 986.00 ±120.20 | 21.12 | 0.956 | ||||
| 宰前活重 Pre-slaughter body weight/g | 2 147.00 ±203.25a | 2 449.00 ±107.65b | 3 059.00 ±187.45c | 68.831 | <0.001 | ||||
| 料重比 Feed/gain | 3.78 ±1.24a | 3.60 ±0.37a | 5.68 ±0.75b | 0.215 | <0.001 | ||||
| 半净膛胴体重 Half eviscerated body weight/g | 1 191.00 ±124.59a | 1 378.27 ±84.77b | 1 770.26 ±114.59c | 43.762 | <0.001 | ||||
| 全净膛胴体重 All eviscerated body weight/g | 1 090.40 ±116.42a | 1 255.10 ±78.44b | 1 602.32 ±97.09c | 38.708 | <0.001 | ||||
| 半净膛屠宰率 Half eviscerated ratio/% | 55.44 ±1.61a | 56.27 ±1.98ab | 57.93 ±2.81b | 0.404 | 0.048 | ||||
| 全净膛屠宰率 All eviscerated ratio/% | 50.74 ±1.30 | 51.19 ±1.77 | 52.41 ±1.88 | 0.292 | 0.116 | ||||
同行数据肩标不同小写字母表示差异显著(P<0.05),相同或无字母表示差异不显著(P>0.05)。下表同。 | |
In the same row, values with different small letter superscripts mean significant difference (P<0.05), while with the same letter or no letter superscripts mean no significant difference (P>0.05). The same as below. |
2.2 不同屠宰日龄莱芜黑兔的肌肉物理性状
表3 不同屠宰日龄莱芜黑兔的肌肉物理性状Table 3 Physical properties of muscle of Laiwu black rabbits at different slaughter ages |
| 项目 Items | 屠宰日龄Slaughter ages | SEM | P值 P-value | ||
|---|---|---|---|---|---|
| 75 | 84 | 115 | |||
| pH45 min | 6.75±0.09 | 6.67±0.15 | 6.65±0.20 | 0.028 | 0.285 |
| pH24 h | 5.91±0.02b | 5.79±0.08a | 5.74±0.08a | 0.017 | 0.045 |
| 亮度L* | 44.21±1.90 | 42.20±3.62 | 42.63±1.48 | 0.470 | 0.187 |
| 红度a* | 4.27±1.29a | 5.47±0.65b | 7.10±1.05c | 0.282 | <0.001 |
| 黄度b* | 6.34±0.91b | 5.90±0.75b | 5.04±0.89a | 0.181 | 0.007 |
| 剪切力Shear force/N | 23.76±1.80 | 26.28±5.42 | 21.79±4.31 | 0.804 | 0.068 |
| 滴水损失Drip loss ratio/% | 2.77±0.76b | 1.72±0.37a | 1.47±0.37a | 0.141 | <0.001 |
| 失水率Water loss ratio/% | 40.31±2.77 | 39.07±4.32 | 40.66±3.43 | 0.640 | 0.579 |
| 熟肉率Cooked meat ratio/% | 63.70±1.18 | 62.95±2.12 | 62.16±1.99 | 0.339 | 0.185 |
2.3 不同屠宰日龄莱芜黑兔的肌肉营养成分
表4 不同屠宰日龄莱芜黑兔肌肉的营养成分Table 4 Nutrient composition of muscle of Laiwu black rabbits at different slaughter ages |
| 项目 Items | 屠宰日龄Slaughter ages | SEM | P值 P-value | ||
|---|---|---|---|---|---|
| 75 | 84 | 115 | |||
| 干物质Dry matter/% | 27.83±2.08a | 28.69±1.78ab | 30.48±2.02b | 0.402 | 0.017 |
| 粗灰分Ash/% | 1.20±0.07 | 1.12±0.05 | 1.17±0.09 | 0.014 | 0.051 |
| 粗蛋白质Crude protein/% | 20.45±1.11 | 19.98±0.46 | 21.50±0.65 | 0.282 | 0.060 |
| 粗脂肪Crude fat/% | 2.43±0.53 | 2.58±0.45 | 2.08±0.79 | 0.171 | 0.516 |
| 生育酚Tocopherol/(mg/kg) | 2.32±0.31 | 2.40±0.28 | 2.68±0.23 | 0.086 | 0.206 |
| 烟酸Nicotinic acid/(mg/kg) | 54.13±4.38c | 44.86±5.05b | 26.04±2.23a | 3.680 | <0.001 |
2.4 不同屠宰日龄莱芜黑兔的肌肉肌红蛋白和黑色素含量
表5 不同屠宰日龄莱芜黑兔的肌肉肌红蛋白和黑色素含量Table 5 Myoglobin and melanin contents of muscle of Laiwu black rabbits at different slaughter ages |
| 项目 Items | 屠宰日龄Slaughter ages | SEM | P值 P-value | ||
|---|---|---|---|---|---|
| 75 | 84 | 115 | |||
| 肌红蛋白Myoglobin/(nmol/mL) | 11.72±0.75a | 14.92±3.51b | 14.75±2.72b | 0.534 | 0.010 |
| 黑色素Melanin/(ng/mL) | 132.29±12.87 | 158.64±16.61 | 141.44±28.33 | 5.676 | 0.158 |
2.5 不同屠宰日龄莱芜黑兔的肌肉风味物质含量
表6 不同屠宰日龄莱芜黑兔的肌肉脂肪酸含量Table 6 Fatty acid contents of muscle of Laiwu black rabbits at different slaughter ages mg/kg |
| 项目 Items | 屠宰日龄Slaughter ages | SEM | P值 P-value | ||
|---|---|---|---|---|---|
| 75 | 84 | 115 | |||
| 二十碳二烯酸 Eicosadienoic acid | 83.5±20.76ab | 100.75±17.00b | 60.75±11.32a | 6.608 | 0.025 |
| 二十二碳酸 Docosarboxylic acid | 31.75±0.96b | 34.00±3.74b | 25.75±2.22a | 1.246 | 0.004 |
| 二十碳三烯酸 Eicosatraenoic acid | 10.25±5.32ab | 17.00±4.97b | 8.25±1.50a | 1.590 | 0.043 |
| 芥酸 Erucic acid | 95.50±3.87b | 91.50±21.86b | 44.00±10.10a | 7.953 | 0.001 |
| 二十二碳二烯酸 Docosadienoic acid | 1.50±1.91ab | 3.25±0.96b | 0.25±0.50a | 0.497 | 0.026 |
| 二十三碳酸 Tricosanoic acid | 19.75±1.71ab | 22.25±3.59b | 16.75±1.50a | 0.933 | 0.034 |
| 二十碳五烯酸 Eicosapentaenoic acid | 20.00±1.83ab | 25.00±6.00b | 14.75±1.89a | 1.602 | 0.013 |
| 饱和脂肪酸SFA | 8 588.50±1 977.79 | 9 367.75±1 635.62 | 7 123.00±2 404.01 | 599.812 | 0.329 |
| 不饱和脂肪酸UFA | 12 323.50±2 728.86 | 13 826.25±2 156.51 | 10 170.00±4 113.93 | 929.660 | 0.296 |
| 单不饱和脂肪酸MUFA | 4 662.50±1 148.80 | 5 385.00±1 072.13 | 4 215.00±1 984.60 | 408.357 | 0.544 |
| 多不饱和脂肪酸PUFA | 7 661.00±1 588.83 | 8 441.25±1 174.56 | 5 955.00±2 130.84 | 538.429 | 0.156 |
表7 不同屠宰日龄莱芜黑兔的肌肉核苷酸含量Table 7 Nucleotide contents of muscle of Laiwu black rabbits at different slaughter ages μg/kg |
| 项目 Items | 屠宰日龄Slaughter ages | SEM | P值 P-value | ||
|---|---|---|---|---|---|
| 75 | 84 | 115 | |||
| 胞嘧啶Cytosine | 6.74±1.08 | 5.71±0.57 | 5.90±0.56 | 0.244 | 0.189 |
| 尿嘧啶Uracil | 30.77±7.80 | 32.15±3.23 | 36.15±1.83 | 1.473 | 0.330 |
| 鸟嘌呤Guanine | 53.90±2.12b | 44.66±2.52a | 42.26±1.23a | 1.603 | <0.001 |
| 腺嘌呤Adenine | 2 327.29±193.56b | 2 032.47±26.14a | 2 375.63±12.59b | 54.421 | 0.004 |
| 次黄嘌呤Hypoxanthine | 157.33±54.01 | 163.62±15.90 | 172.72±17.17 | 9.078 | 0.816 |
表8 不同屠宰日龄莱芜黑兔的肌肉挥发性物质含量Table 8 Volatile substance contents of muscle of Laiwu black rabbits at different slaughter ages μg/kg |
| 项目 Items | 屠宰日龄Slaughter ages | SEM | P值 P-value | ||
|---|---|---|---|---|---|
| 75 | 84 | 115 | |||
| 己醛Hexanal | 137.15±58.31 | 261.93±151.70 | 155.85±48.76 | 30.476 | 0.207 |
| 庚醛Heptaldehyde | 10.40±4.40 | 15.15±2.28 | 13.45±2.58 | 1.030 | 0.164 |
| 辛醛Octyl aldehyde | 1.38±0.43 | 2.25±0.95 | 2.03±0.22 | 0.195 | 0.167 |
| 壬醛Nonanal | 3.30±1.24 | 4.40±1.84 | 2.80±0.78 | 0.408 | 0.284 |
| 己酸Caproic acid | 397.95±90.74 | 491.00±132.63 | 505.83±297.21 | 52.931 | 0.708 |
