1 材料与方法
1.1 试验动物和试验设计
1.2 试验饲粮
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 | 饲粮粗蛋白质水平Dietary crude protein level/% | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 18.00 | 19.00 | 20.00 | 21.00 | 22.00 | |||||||
| 原料Ingredients | |||||||||||
| 玉米Corn | 20.99 | 16.12 | 11.25 | 6.30 | 1.73 | ||||||
| 小麦Wheat | 35.00 | 35.00 | 35.00 | 35.00 | 35.00 | ||||||
| 高粱Sorghum | 12.00 | 14.00 | 16.00 | 18.00 | 20.00 | ||||||
| 豆粕Soybean meal | 10.00 | 12.40 | 14.80 | 17.30 | 19.60 | ||||||
| 菜籽粕Rapeseed meal | 5.00 | 5.00 | 5.00 | 5.00 | 5.00 | ||||||
| 葵花粕Sunflower meal | 6.00 | 6.00 | 6.00 | 6.00 | 6.00 | ||||||
| 玉米蛋白粉Corn gluten meal | 3.00 | 3.20 | 3.40 | 3.60 | 3.80 | ||||||
| 大豆油Soybean oil | 3.40 | 3.80 | 4.20 | 4.60 | 4.80 | ||||||
| 石粉Limestone | 1.07 | 1.05 | 1.03 | 1.00 | 0.98 | ||||||
| 磷酸氢钙CaHPO4 | 1.46 | 1.46 | 1.46 | 1.46 | 1.46 | ||||||
| L-赖氨酸盐酸盐L-Lys·HCl (98.50%) | 0.50 | 0.44 | 0.38 | 0.32 | 0.26 | ||||||
| DL-蛋氨酸DL-Met (99%) | 0.12 | 0.11 | 0.10 | 0.08 | 0.07 | ||||||
| L-苏氨酸L-Thr (99%) | 0.12 | 0.09 | 0.06 | 0.03 | 0.00 | ||||||
| L-色氨酸L-Trp (99%) | 0.04 | 0.03 | 0.02 | 0.01 | 0.00 | ||||||
| 食盐NaCl | 0.30 | 0.30 | 0.30 | 0.30 | 0.30 | ||||||
| 预混料Premix1) | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | ||||||
| 合计Total | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | ||||||
| 营养水平Nutrient levels2) | |||||||||||
| 氮校正表观代谢能AMEn/(MJ/kg) | 11.92 | 11.92 | 11.92 | 11.92 | 11.92 | ||||||
| 粗蛋白质CP | 18.03 | 19.05 | 20.05 | 21.04 | 22.03 | ||||||
| 赖氨酸Lys | 1.10 | 1.10 | 1.10 | 1.10 | 1.10 | ||||||
| 蛋氨酸Met | 0.44 | 0.44 | 0.44 | 0.44 | 0.44 | ||||||
| 蛋氨酸+半胱氨酸Met+Cys | 0.79 | 0.79 | 0.79 | 0.79 | 0.79 | ||||||
| 苏氨酸Thr | 0.74 | 0.74 | 0.74 | 0.74 | 0.74 | ||||||
| 色氨酸Trp | 0.18 | 0.18 | 0.18 | 0.18 | 0.18 | ||||||
| 钙Ca | 0.91 | 0.95 | 0.92 | 0.94 | 0.96 | ||||||
| 总磷TP | 0.69 | 0.67 | 0.65 | 0.68 | 0.64 | ||||||
| 非植酸磷NPP | 0.41 | 0.41 | 0.41 | 0.41 | 0.41 | ||||||
1)预混料为每千克饲粮提供 The premix provided the following per kg of diets:VA 12 000 IU,VB1 2.4 mg,VB2 5.0 mg,VB3 42 mg,VB6 2.8 mg,VB9 1.0 mg,VB12 16 μg,VD3 600 IU,VE 45 IU,VK 2.5 mg,生物素 biotin 0.12 mg,泛酸钙 calcium pantothenate 12 mg,胆碱 choline 1 300 mg,Fe 80 mg,Cu 7 mg,Mn 60 mg,Zn 80 mg,I 0.7 mg,Se 0.15 mg。 2)氮校正表观代谢能、氨基酸和非植酸磷为计算值,均参照《中国饲料成分及营养价值表(2022年第33版)》各原料数据进行计算;粗蛋白质、钙和总磷为实测值,分别参照GB/T 6432—2018、GB/T 6436—2018和GB/T 6437—2018中方法进行测定。AMEn, amino acids and NPP were calculated values, the calculation was made according to the values of each feed material in Tables of Feed Composition and Nutritive Values in China (33rd edition, 2022); CP, Ca and TP were measured values, and methods in GB/T 6432—2018, GB/T 6436—2018 and GB/T 6437—2018 were used for determination, respectively. |
1.3 饲养管理
1.4 样品采集和制备
1.5 测定指标及方法
1.5.1 生长性能
1.5.2 血浆生化指标和肝脏蛋白质代谢指标
1.5.3 肝脏蛋白质代谢相关基因表达
表2 qRT-PCR引物序列Table 2 qRT-PCR primer sequences |
| 基因 Genes | GenBank登录号 GenBank accession number | 引物序列 Primer sequences (5'—3') | 退火温度 Annealing temperature/℃ |
|---|---|---|---|
| 胰岛素样生长因子-1 IGF-1 | NM_001004384.2 | F:CATTTCTTCTACCTTGGC R:TCATCCACTATTCCCTTG | 60 |
| 哺乳动物雷帕霉素靶蛋白 mTOR | XM_417614.7 | F:GGTGATGACCTTGCCAAACT R:CTCTTGTCATCGCAACCTCA | 60 |
| 核糖体蛋白S6激酶1 S6K1 | NM_001030721.1 | F:TGGACCATGGAGGAGTTGG R:AGCACTCCGGTCGGATCTT | 58 |
| 真核翻译起始因子4E结合蛋白1 4EBP1 | XM_424384.7 | F:GCGAATGTAGGTGAAGAAGAG R:AACAGGAAGGCACTCAAGG | 60 |
| β-肌动蛋白 β-actin | NM_205518.2 | F:GAGAAATTGTGCGTGACATCA R:CCTGAACCTCTCATTGCCA | 60 |
1.5.4 盲肠菌群
1.6 数据处理及统计分析
2 结果与分析
2.1 饲粮粗蛋白质水平对中速型黄羽肉鸡生长性能和蛋白质沉积的影响
表3 饲粮粗蛋白质水平对中速型黄羽肉鸡生长性能和蛋白质沉积(干物质基础)的影响Table 3 Effects of dietary crude protein level on growth performance and protein deposition (DM basis) of medium-growing yellow-feathered broilers |
| 项目 Items | 饲粮粗蛋白质水平 Dietary crude protein level/% | 均值 标准误 SEM | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 处理 Treatment | 线性 Linear | 二次 Quadratic | |||||||
| 18.00 | 19.00 | 20.00 | 21.00 | 22.00 | |||||
| 生长性能Growth performance | |||||||||
| 1日龄体重 BW at 1 day of age/g | 29.10 | 29.09 | 29.11 | 29.09 | 29.09 | 0.010 | 0.822 | ||
| 30日龄体重 BW at 30 day of age/g | 547.38c | 604.14b | 625.04ab | 642.21a | 615.67ab | 9.463 | <0.001 | <0.001 | <0.001 |
| 平均日采食量ADFI/g | 37.30 | 37.41 | 38.22 | 38.81 | 38.26 | 0.235 | 0.218 | ||
| 平均日增重ADG/g | 17.28c | 19.17b | 19.87ab | 20.44a | 19.55ab | 0.244 | <0.001 | <0.001 | <0.001 |
| 料重比F/G | 2.16a | 1.95b | 1.93b | 1.90b | 1.96b | 0.020 | <0.001 | <0.001 | <0.001 |
| 粗蛋白质日摄入量 Daily crude protein intake/g | 6.73d | 7.13c | 7.66b | 8.17a | 8.43a | 0.125 | <0.001 | <0.001 | <0.001 |
| 死淘率Mortality/% | 0.00 | 1.11 | 1.11 | 0.00 | 1.11 | 0.555 | 0.161 | ||
| 蛋白质沉积Protein deposition | |||||||||
| 空体蛋白质含量 Empty body protein content/% | 55.36 | 55.60 | 55.48 | 55.36 | 56.55 | 0.564 | 0.966 | ||
| 蛋白质日沉积量 Daily protein deposition/g | 2.99b | 3.50a | 3.50a | 3.54a | 3.31a | 0.056 | 0.002 | 0.091 | <0.001 |
| 蛋白质沉积率 Protein deposition rate/% | 46.23b | 50.84a | 47.21b | 44.90b | 40.19c | 0.824 | <0.001 | 0.001 | <0.001 |
2.2 饲粮粗蛋白质水平对中速型黄羽肉鸡血浆生化指标的影响
表4 饲粮粗蛋白质水平对中速型黄羽肉鸡血浆生化指标的影响Table 4 Effects of dietary crude protein level on plasma biochemical indices of medium-growing yellow-feathered broilers |
| 项目 Items | 饲粮粗蛋白质水平 Dietary crude protein level/% | 均值 标准误 SEM | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 处理 Treatment | 线性 Linear | 二次 Quadratic | |||||||
| 18.00 | 19.00 | 20.00 | 21.00 | 22.00 | |||||
| 总蛋白TP/(g/L) | 29.17 | 32.45 | 31.29 | 31.24 | 29.43 | 0.878 | 0.752 | ||
| 白蛋白ALB/(g/L) | 13.44 | 14.30 | 14.25 | 13.92 | 13.16 | 0.357 | 0.824 | ||
| 球蛋白GLB/(g/L) | 14.03b | 20.98a | 19.52a | 18.48ab | 17.66ab | 0.808 | 0.048 | 0.330 | 0.035 |
| 白蛋白/球蛋白ALB/GLB | 1.13a | 0.58b | 0.79b | 0.69b | 0.69b | 0.049 | <0.001 | 0.011 | 0.003 |
| 尿酸UA/(μmol/L) | 328.32 | 320.42 | 324.49 | 318.66 | 324.10 | 9.045 | 0.998 | ||
| 生长激素GH/(μg/L) | 9.02 | 10.03 | 9.70 | 9.87 | 9.60 | 0.196 | 0.551 | ||
| 胰岛素样生长因子-1 IGF-1/(μg/L) | 23.41 | 24.66 | 24.20 | 25.30 | 25.34 | 0.456 | 0.656 | ||
| 胰岛素样生长因子结合蛋白-5 IGFBP-5/(μg/L) | 28.33 | 29.16 | 26.95 | 27.14 | 26.34 | 0.546 | 0.494 | ||
2.3 饲粮粗蛋白质水平对中速型黄羽肉鸡肝脏蛋白质代谢指标的影响
表5 饲粮粗蛋白质水平对中速型黄羽肉鸡肝脏蛋白质代谢指标的影响Table 5 Effects of dietary crude protein level on protein metabolism indices in liver of medium-growing yellow-feathered broilers |
| 项目 Items | 饲粮粗蛋白质水平 Dietary crude protein level/% | 均值 标准误 SEM | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 处理 Treatment | 线性 Linear | 二次 Quadratic | |||||||
| 18.00 | 19.00 | 20.00 | 21.00 | 22.00 | |||||
| 谷草转氨酶AST/(U/g prot) | 3.30 | 3.29 | 3.46 | 3.82 | 3.76 | 0.108 | 0.368 | ||
| 谷丙转氨酶ALT/(U/g prot) | 0.80 | 0.84 | 0.78 | 0.74 | 0.81 | 0.031 | 0.882 | ||
| 谷草转氨酶/谷丙转氨酶 AST/ALT | 4.08c | 3.99c | 6.03a | 5.72ab | 4.60bc | 0.228 | 0.007 | 0.066 | 0.014 |
| 谷氨酸脱氢酶 GDH/(ng/g prot) | 23.65a | 20.14ab | 17.89b | 16.57b | 23.40a | 0.713 | 0.001 | 0.352 | 0.001 |
| 胰岛素样生长因子-1 IGF-1/(μg/g prot) | 0.71b | 0.75b | 0.91a | 0.76b | 0.73b | 0.024 | 0.042 | 0.711 | 0.052 |
2.4 饲粮粗蛋白质水平对中速型黄羽肉鸡肝脏蛋白质代谢相关基因表达的影响
图1 饲粮粗蛋白质水平对中速型黄羽肉鸡肝脏蛋白质代谢相关基因表达的影响ns表示组间差异不显著(P>0.05),*表示组间差异显著(P<0.05),**表示组间差异极显著(P<0.01)。 Fig.1 Effects of dietary crude protein level on expression of genes related to protein metabolism in liver of medium-growing yellow-feathered broilers ns mean no significant difference between groups (P>0.05), * mean significant difference between groups (P<0.05), and ** mean extremely significant difference between groups (P<0.01). |
2.5 饲粮粗蛋白质水平对中速型黄羽肉鸡盲肠菌群的影响
2.5.1 α多样性分析
表6 饲粮粗蛋白质水平对中速型黄羽肉鸡盲肠菌群α多样性的影响Table 6 Effects of dietary crude protein level on α diversity of cecal microbiota of medium-growing yellow-feathered broilers |
| 项目 Items | 饲粮粗蛋白质水平 Dietary crude protein level/% | 均值标准误 SEM | P值 P-value | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 18.00 | 20.00 | 22.00 | |||||||||
| 物种实际观测丰度Actual observed species abundance | |||||||||||
| Sobs指数Sobs index | 216.10 | 184.20 | 204.11 | 9.974 | 0.422 | ||||||
| 群落丰富度Community richness | |||||||||||
| Ace指数Ace index | 254.77 | 234.10 | 229.47 | 11.727 | 0.658 | ||||||
| Chao1指数Chao1 index | 270.40 | 230.31 | 235.53 | 11.183 | 0.295 | ||||||
| 测序深度Sequencing depth | |||||||||||
| Goods_coverage指数Goods_coverage index/% | 99.68 | 99.68 | 99.72 | 0.019 | 0.534 | ||||||
| 群落多样性Community diversity | |||||||||||
| Shannon指数Shannon index | 2.51 | 2.10 | 2.45 | 0.122 | 0.330 | ||||||
| Simpson指数Simpson index | 0.28 | 0.34 | 0.32 | 0.023 | 0.502 | ||||||
2.5.2 β多样性分析
2.5.3 在门和属水平上组成分析
图3 饲粮粗蛋白质水平对中速型黄羽肉鸡盲肠菌群在门和属水平上相对丰度的影响Proteobacteria:变形菌门;Bacteroidota:拟杆菌门;Firmicutes:厚壁菌门;Unclassified_d_Bacteria:未分类细菌门;Lentisphaerae:黏胶球形菌门;Actinobacteria:放线菌门;Cyanobacteria:蓝细菌门;Campylobacter:弯曲杆菌属;Unclassified_f_Oscillospiraceae:未分类颤螺菌科;Phocaeicola:福西亚菌属;Escherichia:埃希氏菌属;Unclassified_o_Eubacteriales:未分类真细菌目;Bacteroides:拟杆菌属;Alistipes:另枝菌属;Barnesiella:巴恩斯氏菌属;Faecalibacterium:粪杆菌属;Fournierella:富尼埃氏菌属;Mediterraneibacter:地中海杆菌属;Christensenella:克里斯滕森氏菌;Unclassified_f_Lachnospiraceae:未鉴定毛螺菌科;Phascolarctobacterium:考拉杆菌属;Merdimonas:单胞菌属;Anaerotignum:厌氧菌属;Enterococcus:肠球菌属;Bilophila:嗜胆菌属;Butyricicoccus:丁酸球菌属;Parabacteroides:副拟杆菌属;Others:其他。 Fig.3 Effects of dietary crude protein level on relative abundance of cecal microbiota at phylum and genus level of medium-growing yellow-feathered broilers |
2.5.4 差异物种分析
图4 黄羽肉鸡盲肠菌群差异物种Kruskal-Wallis秩和检验和LEfSe分析(LDA得分>2.20)Staphylococcus:葡萄球菌属;Weissella:魏斯氏菌属;Haemophilus:嗜血杆菌属;Leuconostoc:明串珠菌属;Erysipelatoclostridium:丹毒梭菌属;Acinetobacter:不动杆菌属;Gardnerella:加德纳菌属;Fusobacterium:梭杆菌属;Erysipelotrichia:丹毒丝菌纲;Erysipelotrichales:丹毒丝菌目;Erysipelotrichaceae:丹毒丝菌科;Bacteroides clarus:克拉鲁斯拟杆菌;[Ruminococcus] torques:扭链瘤胃球菌;Weissella confusa:融合魏斯氏菌;Leuconostoc mesenteroides:肠膜状明串珠菌;Actinobacteria:放线菌门。 *表示P<0.05,**表示P<0.01,***表示P<0.001。* mean P<0.05, ** mean P<0.01, *** mean P<0.001. Fig.4 Kruskal-Wallis rank-sum test and LEfSe analysis of different species in cecal microbiota of yellow-feathered broilers (LDA score>2.20) |
2.6 1~30日龄中速型黄羽肉鸡饲粮粗蛋白质适宜水平和需要量
表7 二次曲线回归模型估测1~30日龄中速型黄羽肉鸡饲粮粗蛋白质适宜水平和需要量Table 7 Estimation of optimal dietary crude protein level and requirement based on quadratic regression model for medium-growing yellow-feathered broilers from 1 to 30 days of age |
| 项目 Items | 回归方程 Regression equations | 决定系数 R2 | P值 P-value | 饲粮粗蛋白质 适宜水平 Optimal dietary crude protein level/% | 每日粗蛋白质 需要量 Daily crude protein requirement/ (g/d) |
|---|---|---|---|---|---|
| 平均日增重ADG/g | y=-0.406x2+16.838x-154.120 | 0.984 | <0.001 | 20.74 | 8.05 |
| 料重比F/G | y=0.038x2-1.559x+17.947 | 0.946 | <0.001 | 20.51 | 7.96 |
| 蛋白质日沉积量 Daily protein deposition/g | y=-0.103x2+4.190x-38.986 | 0.919 | <0.001 | 20.34 | 7.77 |
| 蛋白质沉积率 Protein deposition rate/% | y=-1.237x2+47.665x-410.280 | 0.901 | <0.001 | 19.27 | 7.21 |
| 球蛋白GLB/(g/L) | y=-1.080x2+43.676x-421.230 | 0.684 | 0.035 | 20.22 | 7.73 |
| 白蛋白/球蛋白ALB/GLB | y=0.056x2-2.334x+24.775 | 0.581 | 0.003 | 20.84 | 8.09 |
| 谷草转氨酶/谷丙转氨酶 AST/ALT | y=-0.315x2+12.877x-126.030 | 0.609 | 0.014 | 20.44 | 7.81 |
| 谷氨酸脱氢酶 GDH/(ng/g prot) | y=1.544x2-62.150x+642.810 | 0.863 | 0.001 | 20.13 | 7.69 |

京公网安备 11010802041926号