Lu C D, Potchoiba M J
Am. Inst. for Goat Res., Langston University, OK 73050.
J Anim Sci. 1990 Jun;68(6):1751-9. doi: 10.2527/1990.6861751x.
Growing goats, 45 Alpine and 45 Nubian, were used in a 3 x 3 factorial arrangement to quantify the influence of dietary energy and protein levels on daily DM intake and nutrient utilization for growth. Goats had ad libitum access to complete mixed diets containing either 2.46, 2.77 or 3.05 Mcal/kg ME plus 11.2, 12.7 or 15.1% CP for 16 wk. Dry matter intake decreased curvilinearly as dietary ME density increased (P less than .001). Dry matter intake increased linearly (P less than .05) as dietary CP level increased during all growth intervals except wk 25 to 28 of age. Average daily gain was 115, 113 and 99 g/d for goats fed diets containing 2.46, 2.77 and 3.05 Mcal/kg ME, respectively. Average daily gain was 104, 106 and 117 g/d for goats fed diets with 11.2, 12.7 and 15.1% CP, respectively. Dry matter intake was higher (P less than .01) for Alpine than for Nubian goats, whereas ADG was similar between breeds. Intake of ME was 248, 260 and 198 kcal/(kg.75.d) for goats fed the low- medium- and high-energy diets, respectively. Intake of CP was 9.1, 10.7 and 13.2 g/(kg.75.d) for goats fed low-, medium- and high-protein diets, respectively. Average requirements for growth derived from regression analysis of all data points were 4.6 kcal ME and .26 g CP/g ADG. The prediction equation for intake of growing goats of 4 to 8 mo of age was: DMI, g/d = 1,749 - 496 DE, kcal/g + 18 live weight, kg + 3 ADG, g/d; r2 = .73 (Sy.x = 127, P less than .0001, n = 90). The requirement of ME for growth was 33% lower than the value recommended in 1981 by the National Research Council.
选用45只阿尔卑斯山羊和45只努比亚山羊，采用3×3析因设计，以量化日粮能量和蛋白质水平对生长山羊日干物质采食量和养分利用率的影响。山羊连续16周自由采食含2.46、2.77或3.05兆卡/千克代谢能（ME）加11.2%、12.7%或15.1%粗蛋白（CP）的全混合日粮。随着日粮代谢能密度的增加，干物质采食量呈曲线下降（P<0.001）。在除25至28周龄外的所有生长阶段，随着日粮粗蛋白水平的增加，干物质采食量呈线性增加（P<0.05）。采食含2.46、2.77和3.05兆卡/千克代谢能日粮的山羊，平均日增重分别为115、113和99克/天。采食含11.2%、12.7%和15.1%粗蛋白日粮的山羊，平均日增重分别为104、106和117克/天。阿尔卑斯山羊的干物质采食量高于努比亚山羊（P<0.01），而两品种间的平均日增重相似。采食低、中、高能量日粮的山羊，代谢能摄入量分别为248、260和198千卡/（千克0.75·天）。采食低、中、高蛋白质日粮的山羊，粗蛋白摄入量分别为9.1、10.7和13.2克/（千克0.75·天）。对所有数据点进行回归分析得出的生长平均需要量为4.6千卡代谢能和0.26克粗蛋白/克平均日增重。4至8月龄生长山羊采食量的预测方程为：干物质采食量，克/天=1749 - 496×消化能，千卡/克+18×体重，千克+3×平均日增重，克/天；r2 = 0.73（Sy.x = 127，P<0.0001，n = 90）。生长所需的代谢能比1981年美国国家研究委员会推荐的值低33%。
