1 材料与方法
1.1 试验设计与饲粮
表1 育肥期饲粮组成及营养水平(干物质基础)Table 1 Composition and nutrient levels of the finishing-phase diet (DM basis) |
| 项目Items | 含量Content | ||
|---|---|---|---|
| 原料Ingredients | |||
| 玉米Corn | 8.47 | ||
| 豆粕Soybean meal | 3.33 | ||
| 麸皮Wheat bran | 1.11 | ||
| 大豆秸秆Soybean straw | 14.53 | ||
| 花生秧Peanut vine | 14.53 | ||
| 豆腐渣Tofu residue | 47.45 | ||
| 大蒜皮Garlic peel | 9.44 | ||
| 碳酸氢钠NaHCO3 | 0.21 | ||
| 食盐NaCl | 0.11 | ||
| 预混料Premix1) | 0.82 | ||
| 合计Total | 100.00 | ||
| 营养水平Nutrient levels2) | |||
| 消化能DE/(MJ/kg) | 12.32 | ||
| 干物质(风干基础) DM (air-dry basis) | 89.25 | ||
| 粗蛋白质CP | 12.6 | ||
| 粗脂肪EE | 2.1 | ||
| 粗灰分Ash | 5.7 | ||
| 钙Ca | 0.9 | ||
| 总磷TP | 0.2 | ||
| 中性洗涤纤维NDF | 33.5 | ||
| 酸性洗涤纤维ADF | 15.7 |
1)预混料为每千克饲粮提供 The premix provided the following per kg of the diet:Fe 61.24 mg,Cu 7.75 mg,Mn 33.7 mg,Zn 52 mg,I 0.59 mg,Se 0.25 mg,Co 0.28 mg,VA 1 500 IU,VE 23 IU。 2)消化能为根据NY/T 816—2004所得计算值,其余为实测值。DE was a calculated value according to NY/T 816—2004, while the others were measured values. |
表2 2组湖羊不同饲养阶段的ADGTable 2 ADG of Hu sheep in two groups during different feeding stages |
| 项目 Items | 组别Groups | 均值标准误 SEM | P值 P-value | |
|---|---|---|---|---|
| HADG | LADG | |||
| 出生至断奶Birth to weaning | 298.16 | 215.17 | 19.066 | 0.023 |
| 断奶至6月龄Weaning to 6 months of age | 267.30 | 156.55 | 15.682 | <0.001 |
| 出生至6月龄Birth to 6 months of age | 278.65 | 176.43 | 13.742 | <0.001 |
1.2 样品采集与指标测定
1.2.1 饲粮养分含量
1.2.2 屠宰性能
1.2.3 背最长肌食用品质与常规养分含量
1.2.4 背最长肌脂肪酸与氨基酸组成
1.3 数据统计分析
2 结果与分析
2.1 不同生长速率湖羊屠宰性能差异
表3 不同生长速率湖羊的屠宰性能差异Table 3 Differences in slaughter performance of Hu sheep with different growth rates |
| 项目 Items | 组别Groups | 均值标准误 SEM | P值 P-value | |
|---|---|---|---|---|
| HADG | LADG | |||
| 宰前活重Pre-slaughter live weight/kg | 49.14 | 33.70 | 2.340 | <0.001 |
| 胴体重Carcass weight/kg | 24.50 | 16.60 | 1.193 | <0.001 |
| 屠宰率Dressing percentage/% | 49.90 | 49.28 | 0.558 | 0.590 |
| GR值GR value/mm | 13.20 | 9.75 | 0.606 | 0.001 |
| 背膘厚Backfat thickness/mm | 3.20 | 2.13 | 0.361 | 0.141 |
| 肾周脂重Perirenal fat weight/g | 108.03 | 76.84 | 10.766 | 0.154 |
| 大网膜脂重Omentum majus fat weight/g | 409.59 | 208.06 | 44.154 | 0.016 |
| 尾脂重Tail fat weight/g | 778.33 | 352.78 | 71.305 | <0.001 |
| 肾周脂占比Perirenal fat percentage/% | 0.22 | 0.23 | 0.022 | 0.872 |
| 大网膜脂占比Omentum majus fat percentage/% | 0.83 | 0.62 | 0.078 | 0.189 |
| 尾脂占比Tail fat percentage/% | 1.60 | 1.06 | 0.125 | 0.024 |
2.2 不同生长速率湖羊背最长肌食用品质差异
2.2.1 嫩度与持水性
表4 不同生长速率湖羊背最长肌嫩度与持水性差异Table 4 Differences in tenderness and water-holding capacity in longissimus dorsi of Hu sheep with different growth rates |
| 项目 Items | 组别Groups | 均值标准误 SEM | P值 P-value | |
|---|---|---|---|---|
| HADG | LADG | |||
| 滴水损失Drip loss/% | 1.43 | 1.78 | 0.114 | 0.129 |
| 蒸煮损失Cooking loss/% | 32.93 | 36.16 | 0.792 | 0.036 |
| 剪切力Shear force/N | 35.56 | 44.01 | 2.892 | 0.149 |
2.2.2 肉色与pH
表5 不同生长速率湖羊背最长肌肉色与pH差异Table 5 Differences in meat color and pH in longissimus dorsi of Hu sheep with different growth rates |
| 项目 Items | 组别Groups | 均值标准误 SEM | P值 P-value | ||
|---|---|---|---|---|---|
| HADG | LADG | ||||
亮度L* | 45 min | 34.85 | 35.86 | 0.654 | 0.459 |
| 24 h | 38.03 | 40.79 | 0.744 | 0.059 | |
红度a* | 45 min | 7.50 | 7.39 | 0.267 | 0.847 |
| 24 h | 7.80 | 8.75 | 0.355 | 0.187 | |
黄度b* | 45 min | 7.29 | 7.60 | 0.272 | 0.580 |
| 24 h | 8.40 | 9.98 | 0.289 | 0.014 | |
pH | 45 min | 6.41 | 6.34 | 0.049 | 0.444 |
| 24 h | 6.25 | 5.84 | 0.226 | 0.389 | |
2.3 不同生长速率湖羊背最长肌常规养分含量差异
表6 不同生长速率湖羊背最长肌常规养分含量差异Table 6 Differences in conventional nutrient contents in longissimus dorsi of Hu sheep with different growth rates |
| 项目 Items | 组别Groups | 均值标准误 SEM | P值 P-value | |
|---|---|---|---|---|
| HADG | LADG | |||
| 水分Moisture | 76.87 | 76.00 | 0.203 | 0.027 |
| 粗蛋白质CP | 20.43 | 19.99 | 0.225 | 0.342 |
| 粗脂肪EE | 2.23 | 1.64 | 0.141 | 0.030 |
| 粗灰分Ash | 1.18 | 1.24 | 0.035 | 0.385 |
2.4 不同生长速率湖羊背最长肌脂肪酸组成差异
2.4.1 饱和脂肪酸(SFA)含量
表7 不同生长速率湖羊背最长肌SFA含量差异Table 7 Differences in SFA contents in longissimus dorsi of Hu sheep with different growth rates |
| 项目 Items | 组别Groups | 均值标准误 SEM | P值 P-value | |
|---|---|---|---|---|
| HADG | LADG | |||
| 辛酸C8∶0 | 0.025 | 0.017 | 0.001 6 | 0.012 |
| 癸酸C10∶0 | 0.063 | 0.063 | 0.013 0 | 1.000 |
| 月桂酸C12∶0 | 0.170 | 0.110 | 0.012 5 | 0.010 |
| 十三烷酸C13∶0 | 0.014 | 0.010 | 0.001 0 | 0.065 |
| 肉豆蔻酸C14∶0 | 2.198 | 1.351 | 0.173 4 | 0.009 |
| 十五烷酸C15∶0 | 0.270 | 0.206 | 0.019 0 | 0.090 |
| 棕榈酸C16∶0 | 20.998 | 13.577 | 1.653 7 | 0.019 |
| 十七烷酸C17∶0 | 0.865 | 0.656 | 0.064 5 | 0.106 |
| 硬脂酸C18∶0 | 16.556 | 13.203 | 1.267 7 | 0.196 |
| 花生酸C20∶0 | 0.118 | 0.105 | 0.008 3 | 0.414 |
| 二十一烷酸C21∶0 | 0.344 | 0.378 | 0.023 1 | 0.484 |
| 山嵛酸C22∶0 | 0.097 | 0.105 | 0.005 6 | 0.511 |
| 二十三烷酸C23∶0 | 0.106 | 0.118 | 0.006 7 | 0.350 |
| 木蜡酸C24∶0 | 0.117 | 0.117 | 0.006 8 | 0.972 |
| 饱和脂肪酸SFA | 41.941 | 30.016 | 3.110 6 | 0.051 |
2.4.2 不饱和脂肪酸(UFA)含量
表8 不同生长速率湖羊背最长肌UFA含量差异Table 8 Differences in UFA contents in longissimus dorsi of Hu sheep with different growth rates |
| 项目 Items | 组别Groups | 均值标准误 SEM | P值 P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| HADG | LADG | ||||||||
| 肉豆蔻烯酸C14∶1 | 0.087 | 0.050 | 0.008 3 | 0.020 | |||||
| 棕榈油酸C16∶1 | 1.163 | 0.763 | 0.096 3 | 0.032 | |||||
| 油酸C18∶1n9c | 33.172 | 22.536 | 2.656 9 | 0.040 | |||||
| 二十碳一烯酸C20∶1 | 0.104 | 0.086 | 0.005 3 | 0.078 | |||||
| 芥酸C22∶1n9 | 0.096 | 0.081 | 0.010 0 | 0.490 | |||||
| 二十四碳一烯酸C24∶1 | 0.060 | 0.057 | 0.004 1 | 0.672 | |||||
| 单不饱和脂肪酸MUFA | 34.683 | 23.572 | 2.761 9 | 0.039 | |||||
| α-亚麻酸C18∶3n3 | 0.372 | 0.294 | 0.022 6 | 0.084 | |||||
| α-亚麻烯酸C20∶3n3 | 0.039 | 0.034 | 0.002 1 | 0.231 | |||||
| 二十碳五烯酸C20∶5n3 | 0.079 | 0.087 | 0.005 2 | 0.470 | |||||
| 二十二碳六烯酸C22∶6n3 | 0.085 | 0.095 | 0.006 8 | 0.449 | |||||
| n-3多不饱和脂肪酸n-3 PUFA | 0.576 | 0.511 | 0.028 8 | 0.276 | |||||
| 亚油酸C18∶2n6c | 6.919 | 5.947 | 0.372 2 | 0.202 | |||||
| 二十碳三烯酸C20∶3n6 | 0.179 | 0.187 | 0.011 7 | 0.745 | |||||
| 花生四烯酸C20∶4n6 | 2.189 | 2.249 | 0.127 7 | 0.823 | |||||
| n-6多不饱和脂肪酸n-6 PUFA | 9.286 | 8.383 | 0.489 3 | 0.374 | |||||
| 二十二碳二烯酸C22∶2 | 0.067 | 0.047 | 0.005 5 | 0.062 | |||||
| 多不饱和脂肪酸PUFA | 9.928 | 8.940 | 0.518 8 | 0.358 | |||||
| 不饱和脂肪酸UFA | 44.611 | 32.512 | 3.122 2 | 0.048 | |||||
2.4.3 脂肪酸相关比值及指数
表9 不同生长速率湖羊背最长肌脂肪酸相关比值及指数差异Table 9 Differences in fatty acid-related ratios and indexes in longissimus dorsi of Hu sheep with different growth rates |
| 项目 Items | 组别Groups | 均值标准误 SEM | P值 P-value | |
|---|---|---|---|---|
| HADG | LADG | |||
| 饱和脂肪酸/不饱和脂肪酸SFA/UFA | 0.935 | 0.926 | 0.016 7 | 0.790 |
| 单不饱和脂肪酸/多不饱和脂肪酸MUFA/PUFA | 3.527 | 2.570 | 0.228 9 | 0.031 |
| n-6多不饱和脂肪酸/n-3多不饱和脂肪酸 n-6 PUFA/n-3 PUFA | 16.150 | 16.391 | 0.329 2 | 0.728 |
| 致动脉粥样硬化指数IA | 0.667 | 0.594 | 0.020 7 | 0.078 |
| 血栓形成指数IT | 1.773 | 1.735 | 0.033 5 | 0.583 |
2.5 不同生长速率湖羊背最长肌氨基酸组成差异
表10 不同生长速率湖羊背最长肌氨基酸组成差异Table 10 Differences in amino acid composition in longissimus dorsi of Hu sheep with different growth rates |
| 项目 Items | 组别Groups | 均值标准误 SEM | P值 P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| HADG | LADG | ||||||||
| 必需氨基酸EAA | |||||||||
| 苏氨酸Thr | 3.495 | 3.495 | 0.087 3 | 0.995 | |||||
| 蛋氨酸Met | 2.096 | 2.081 | 0.026 8 | 0.808 | |||||
| 亮氨酸Leu | 6.110 | 6.085 | 0.156 9 | 0.943 | |||||
| 缬氨酸Val | 3.855 | 3.815 | 0.099 5 | 0.849 | |||||
| 赖氨酸Lys | 6.802 | 6.762 | 0.171 2 | 0.909 | |||||
| 色氨酸Trp | 0.983 | 1.014 | 0.008 8 | 0.097 | |||||
| 苯丙氨酸Phe | 3.001 | 3.019 | 0.072 0 | 0.908 | |||||
| 异亮氨酸Ile | 3.602 | 3.572 | 0.089 2 | 0.868 | |||||
| 非必需氨基酸NEAA | |||||||||
| 丝氨酸Ser | 2.960 | 2.977 | 0.073 6 | 0.916 | |||||
| 谷氨酸Glu* | 12.450 | 12.539 | 0.300 0 | 0.887 | |||||
| 脯氨酸Pro | 3.044 | 2.963 | 0.069 3 | 0.576 | |||||
| 甘氨酸Gly* | 3.384 | 3.365 | 0.069 1 | 0.897 | |||||
| 丙氨酸Ala* | 4.505 | 4.484 | 0.106 1 | 0.933 | |||||
| 胱氨酸Cys | 0.883 | 0.890 | 0.011 4 | 0.835 | |||||
| 酪氨酸Tyr | 3.032 | 3.038 | 0.075 2 | 0.981 | |||||
| 组氨酸His | 2.431 | 2.369 | 0.072 4 | 0.681 | |||||
| 精氨酸Arg* | 4.761 | 4.761 | 0.114 8 | 0.992 | |||||
| 天冬氨酸Asp* | 6.972 | 6.937 | 0.174 5 | 0.927 | |||||
| 鲜味氨基酸UAA | 32.072 | 32.086 | 0.759 6 | 0.992 | |||||
| 必需氨基酸EAA | 29.945 | 29.842 | 0.691 9 | 0.945 | |||||
| 非必需氨基酸NEAA | 44.422 | 44.323 | 1.044 8 | 0.964 | |||||
| 必需氨基酸/非必需氨基酸EAA/NEAA | 67.428 | 67.331 | 0.136 2 | 0.736 | |||||
| 总氨基酸TAA | 74.367 | 74.165 | 1.735 4 | 0.957 | |||||
| 必需氨基酸/总氨基酸EAA/TAA | 40.272 | 40.238 | 0.048 6 | 0.736 | |||||
*表示鲜味氨基酸。 | |
* indicated umami amino acids. |
