The aim of this study was to estimate the energy and protein requirements for maintenance and growth of lambs. A total of 35 crossbreed Dorper x Santa Ines lambs (31 ± 1.28 kg of initial body weight (BW) and 4-months old) were distributed in a completely randomized design with three treatments groups (ad libitum, 30% and 60% of feed restriction). Five lambs were slaughtered at the beginning of the experimental trial as a reference group to estimate the initial empty BW (EBW) and body composition. When the animals of the ad libitum treatment reached a BW average of 47.2 kg, at day 84 of trial, all lambs were slaughtered. The feed restriction promoted reduction in body fat (P < 0.001) and energy concentration (P < 0.001), while protein showed a quadratic response (P = 0.05). The equations obtained to NEg and NPg requirements were 0.2984 × EBW0.75 × EBWG0.8069 and 248.617 × EBW-0.15546, respectively. The net energy (NEm) and protein (NPm) for maintenance were 71.00 kcal/kg EBW0.75/day and 1.76 g/kg EBW0.75/day, respectively. In conclusion, the NEg and NPg requirement for lambs with 30 kg of BW and 200 g of average daily gain (ADG) were 0.736 Mcal/day and 24.38 g/day, respectively. Our findings indicate that the NEm for crossbreed Dorper x Santa Ines lambs is similar to those recommended by the international committees, however we support the hypothesis the requirements for gain are lower.

中文翻译：

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雄性Dorper x Santa Ines羔羊的维持和生长要求

这项研究的目的是估计维持和生长羔羊所需的能量和蛋白质。完全随机设计的总共35只杂种Dorper x Santa Ines羔羊（初始体重（BW）为31±1.28 kg，4个月大）分为三个处理组（随意，饲料的30％和60％）限制）。在实验开始之初，宰杀了五只羔羊，作为参考组，以估计初始的空腹体重（EBW）和身体成分。在试验的第84天，当自由采食的动物的体重平均达到47.2kg时，将所有的羔羊都屠宰。进食限制促进了体内脂肪的减少（P <0.001）和能量浓度（P <0.001），而蛋白质则表现出二次反应（P = 0.05）。满足NEg和NPg要求的公式为0.2984×EBW0。75×EBWG0.8069和248.617×EBW-0.15546。维持的净能量（NEm）和蛋白质（NPm）分别为71.00 kcal / kg EBW0.75 /天和1.76 g / kg EBW0.75 /天。总之，体重为30千克体重和平均每日增重200克（ADG）的羔羊的NEg和NPg需求分别为0.736 Mcal /天和24.38 g /天。我们的研究结果表明，多珀x圣伊内斯杂交羔羊的NEm与国际委员会建议的相似，但是我们支持这一假设，即对增肥的要求较低。分别为736麦卡尔/天和24.38克/天。我们的研究结果表明，多珀x圣伊内斯杂交羔羊的NEm与国际委员会建议的相似，但是我们支持这一假设，即对增肥的要求较低。分别为736麦卡尔/天和24.38克/天。我们的研究结果表明，多珀x圣伊内斯杂交羔羊的NEm与国际委员会建议的相似，但是我们支持这一假设，即对增肥的要求较低。