1 材料与方法
1.1 试验设计
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 | 饲粮钙水平Dietary Ca levels/% | |||
|---|---|---|---|---|
| 0.49 | 0.54 | 0.59 | 0.64 | |
| 原料Ingredients | ||||
| 精料补充料Concentrate supplement1) | 11.28 | 12.12 | 10.95 | 12.43 |
| 青贮玉米Corn silage | 88.72 | 87.88 | 89.05 | 87.57 |
| 合计Total | 100.00 | 100.00 | 100.00 | 100.00 |
| 营养水平Nutrient levels2) | ||||
| 粗蛋白质CP | 11.28 | 11.33 | 11.26 | 11.34 |
| 中性洗涤纤维NDF | 56.04 | 55.67 | 56.08 | 55.58 |
| 酸性洗涤纤维ADF | 48.38 | 47.96 | 48.49 | 47.81 |
| 磷P | 0.24 | 0.25 | 0.24 | 0.25 |
| 钙Ca | 0.49 | 0.54 | 0.59 | 0.64 |
| 钙磷比Ca to P ratio | 2.04∶1 | 2.16∶1 | 2.46∶1 | 2.56∶1 |
1)钙水平为0.49%、0.54%、0.59%和0.64%的饲粮分别对应表2中钙水平为0.35%、0.80%、1.25%和1.70%的精料补充料。The diets with Ca levels of 0.49%, 0.54%, 0.59% and 0.64% correspond to the concentrate supplements with Ca levels of 0.35%, 0.80%, 1.25% and 1.70% in Table 2, respectively. 2)营养水平中,钙磷比为计算值,其他指标均为实测值。In nutrient levels, Ca to P ratio was a calculated value, while the other indexes were all measured values. |
表2 精料补充料组成及营养水平(风干基础)Table 2 Composition and nutrient levels of the concentrate supplements (air-dry basis) % |
| 项目 Items | 精料补充料钙水平Concentrate supplement Ca levels/% | |||
|---|---|---|---|---|
| 0.35 | 0.80 | 1.25 | 1.70 | |
| 原料Ingredients | ||||
| 玉米Corn | 39.50 | 44.55 | 43.15 | 41.50 |
| 麦麸Wheat bran | 38.50 | 30.00 | 30.00 | 30.00 |
| 豆粕Soybean meal | 16.80 | 18.80 | 18.90 | 19.25 |
| 磷酸二氢钠NaH2PO4 | 1.55 | 1.65 | 1.65 | 1.65 |
| 石粉Limestone | 0.65 | 2.00 | 3.30 | 4.60 |
| 食盐NaCl | 1.00 | 1.00 | 1.00 | 1.00 |
| 预混料Premix1) | 1.00 | 1.00 | 1.00 | 1.00 |
| 小苏打NaHCO3 | 1.00 | 1.00 | 1.00 | 1.00 |
| 合计Total | 100.00 | 100.00 | 100.00 | 100.00 |
| 营养水平Nutrient levels2) | ||||
| 产奶净能NEL/(MJ/kg) | 6.60 | 6.60 | 6.50 | 6.50 |
| 粗蛋白质CP | 16.05 | 16.09 | 16.07 | 16.09 |
| 中性洗涤纤维NDF | 23.39 | 22.89 | 22.62 | 23.14 |
| 酸性洗涤纤维ADF | 6.59 | 6.44 | 6.20 | 6.36 |
| 钙Ca | 0.35 | 0.80 | 1.25 | 1.70 |
| 磷P | 0.80 | 0.80 | 0.80 | 0.80 |
1)每千克预混料提供 One premix provided the following:VA 600 000 IU,VD 300 000 IU,VE 2 600 IU,Fe 6.0 g,Cu 1.5 g,Mn 4.5 g,Zn 5.5 g,I 60 mg,Se 50 mg,Co 30 mg。 2)产奶净能参考《中国饲料成分及营养价值表(2022年第33版)》计算得出,其余均为实测值。NEL was a calculated value according to Tables of Feed Composition and Nutritive Values in China (33rd edition, 2022), while the others were measured values. |
1.2 饲养管理
1.3 样本采集
1.3.1 饲料样
1.3.2 粪样、尿样
1.4 测定指标及方法
1.4.1 生长性能的测定
1.4.2 饲粮样、粪样和尿样中常规养分含量的测定
1.4.3 养分表观消化率和钙代谢指标的计算
1.5 数据处理与分析
2 结果与分析
2.1 饲粮钙水平对生长奶水牛生长性能的影响
表3 饲粮钙水平对生长奶水牛生长性能的影响Table 3 Effects of dietary Ca level on growth performance of growing dairy buffaloes |
| 项目 Items | 饲粮钙水平Dietary Ca levels/% | |||
|---|---|---|---|---|
| 0.49 | 0.54 | 0.59 | 0.64 | |
| 初重IBW/kg | 228.75±22.47 | 219.38±56.65 | 232.00±29.81 | 211.25±47.81 |
| 末重FBW/kg | 259.00±22.87 | 247.50±56.15 | 264.88±31.22 | 242.75±47.80 |
| 平均日增重ADG/(kg/d) | 0.80±0.09 | 0.74±0.07 | 0.87±0.04 | 0.83±0.07 |
| 干物质采食量DMI/(kg/d) | 5.63±0.28a | 5.34±0.49ab | 5.75±0.35a | 5.25±0.45b |
| 料重比F/G | 8.16±0.61 | 8.13±1.10 | 7.64±0.61 | 7.61±1.13 |
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)。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). The same as below. |
2.2 饲粮钙水平对生长奶水牛养分表观消化率的影响
表4 饲粮钙水平对生长奶水牛养分表观消化率的影响Table 4 Effects of dietary Ca level on nutrient apparent digestibility of growing dairy buffaloes % |
| 项目 Items | 饲粮钙水平Dietary Ca levels/% | |||
|---|---|---|---|---|
| 0.49 | 0.54 | 0.59 | 0.64 | |
| 干物质DM | 59.98±2.70 | 60.39±3.93 | 59.71±3.74 | 60.43±3.38 |
| 粗蛋白质CP | 59.02±1.89 | 59.32±3.38 | 58.87±3.07 | 58.77±3.17 |
| 钙Ca | 35.76±6.63ab | 37.89±9.28a | 32.10±6.80ab | 29.84±8.92b |
| 磷P | 38.07±6.89ab | 44.74±9.14a | 36.51±7.85b | 36.13±6.75b |
2.3 饲粮钙水平对生长奶水牛钙代谢的影响
表5 饲粮钙水平对生长奶水牛钙代谢的影响Table 5 Effects of dietary Ca level on calcium metabolism of growing dairy buffaloes |
| 项目 Items | 饲料钙水平Dietary Ca level/% | |||
|---|---|---|---|---|
| 0.49 | 0.54 | 0.59 | 0.64 | |
| 食入钙Ca intake/(g/d) | 26.02±1.59d | 34.65±1.15c | 44.34±1.65b | 52.76±2.27a |
| 粪排泄钙Fecal Ca excretion/(g/d) | 19.58±2.65d | 26.78±3.67c | 34.83±3.10b | 43.22±4.80a |
| 尿排泄钙Urine Ca excretion/(g/d) | 2.57±0.69c | 3.74±0.71b | 3.58±0.45b | 5.02±0.95a |
| 总排泄钙Total Ca excretion/(g/d) | 21.57±2.63d | 30.52±3.65c | 38.41±3.33b | 48.24±5.09a |
| 粪排泄钙占食入钙的比例 Fecal Ca excretion to Ca intake ratio/% | 83.34±5.35 | 77.21±9.64 | 78.64±7.62 | 81.85±7.44 |
| 粪排泄钙占总排泄钙的比例 Fecal Ca excretion to total Ca excretion ratio/% | 87.94±3.43b | 87.59±2.77b | 90.65±1.03a | 89.56±1.86ab |
| 尿排泄钙占食入钙的比例 Urine Ca excretion to Ca intake ratio/% | 10.18±2.91a | 10.82±2.23a | 8.08±1.01b | 9.53±1.85ab |
| 尿排泄钙占总排泄钙的比例 Urine Ca excretion to total Ca excretion ratio/% | 12.06±3.40a | 12.41±2.70a | 9.35±1.03b | 10.44±1.86ab |
2.4 生长奶水牛钙的维持需要量
3 讨论
3.1 饲粮钙水平对生长奶水牛生长性能的影响
3.2 饲粮钙水平对生长奶水牛钙消化代谢的影响
3.3 生长奶水牛钙的维持需要量
表6 不同反刍动物钙的维持需要量Table 6 Ca maintenance requirements for different ruminants |
| 编号 No. | 品种 Breeds | 钙维持需要量 Ca maintenance requirement | 线性回归方程 (x:食入钙,y:排泄钙) Linear regression equation (x: Ca intake, y: Ca excretion) | 决定系数 R2 | 参考文献 References |
|---|---|---|---|---|---|
| 1 | 泌乳水牛 | 33.80 mg/(kg BW·d) | y=0.45x+33.80 | 0.85 | [27] |
| 2 | 非产绒期绒山羊 | 8.71 mg/(kg LW·d) | y=0.759 4x+8.713 3 | 0.998 5 | [28] |
| 3 | 产绒期绒山羊 | 10.52 mg/(kg LW·d) | y=0.717 3x+10.523 | 0.988 1 | [28] |
| 4 | 妊娠前期云南半细毛羊 | 0.095 g/(kg W0.75·d) | y=0.816x+0.019 | 0.998 | [29] |
| 5 | 妊娠中期云南半细毛羊 | 0.175 g/(kg W0.75·d) | y=0.771x+0.029 | 0.999 | [29] |
| 6 | 妊娠后期云南半细毛羊 | 0.173 2 g/(kg W0.75·d) | y=0.772x+0.036 9 | 0.998 | [30] |
| 7 | 萨宁山羊 | 12 mg/(kg BW·d) | y=0.04x+11.6 | 未给出 | [31] |
| 8 | 生长奶水牛 | 1.753 7 g/(kg W0.75·d) | y=0.005 8x+0.176 6 | 0.962 2 | 本试验 |
