摘要
This study was carried out to to evaluate how feed restriction and different forage:concentrate ratios affect digestibility, methane emission (using the SF6 technique), and energy utilization of Anglo-Nubian goats. Fifteen (15) dry and non-pregnant Anglo Nubian goats, averaging 30±2.9 kg body weight, were used. The experiment was divided into two trials, the first of which was designed to study the effects of feed restriction (0% or ad libitum; 15% of feed restriction or equivalent to 85% of ad libitum intake; and 40% of feed restriction or equivalent to 60% of ad libitum intake) and the second, to study the effects of forage:concentrate (F:C) ratios (75:25, 54:46, and 25:75) in the diet. The sulfur hexafluoride (SF6) tracer gas method was used to collect and estimate methane (CH4) emissions. Feed restriction level did not affect apparent total tract digestibility of dry matter (DM), organic matter, crude protein, and neutral detergent fiber. Methane emission (g d−1) decreased linearly as intake level decreased. However, energy loss in methane proportional to organic matter intake was similar among levels of feed restriction; consequently, dietary metabolizability did not differ among treatments. Methane gas (g d−1) as a function of F:C ratio revealed a quadratic response, showing the highest values when animals were fed the 46:54 F:C ratio diet (18.2 g d−1), suggesting that the decrease in absolute CH4 occurred when the level of concentrate inclusion in the diet surpassed approximately 50%. The results presented herein may be relevant for the ongoing and future efforts towards completion of an IPCC inventory regarding the contribution of goats to the greenhouse gas effects on the planet.
摘要译文
本研究旨在评估饲料限制和不同饲料：浓缩物比例如何影响消化率，甲烷排放（使用SF6技术），和盎格鲁努比亚山羊的能量利用。使用十五（15）只干燥和未怀孕的Anglo Nubian山羊，平均体重30±2.9kg。实验分为两个试验，第一个旨在研究饲料限制的影响（0％或自由采食; 15％的饲料限制或相当于85％的自由采食;40％的饲料限制或相当于60％的自由采食量）和第二，研究饲料的影响：浓缩（F：C）比例（75：25,54：46和25:75）饮食。六氟化硫（SF6）示踪气体方法用于收集和估算甲烷（CH4）排放。饲料限制水平不影响干物质（DM）的表观总肠道消化率，有机物，粗蛋白和中性洗涤纤维。随着摄入水平的降低，甲烷排放量（g d-1）呈线性下降。然而，与有机物质摄入成比例的甲烷能量损失在饲料限制水平上相似;因此，饮食代谢能力在治疗之间没有差异。作为F：C比的函数的甲烷气体（g d-1）显示出二次响应，显示当动物饲喂46:54 F：C比例饮食（18.2g d-1）时的最高值，表明当饮食中的浓缩物含量超过约50％时，绝对CH4的减少发生。本文提供的结果可能与完成IPCC清单的持续和未来努力相关，该清单涉及山羊对地球温室气体影响的贡献。
LIMA, Ana Rebeca Castro et al.. Effects of feed restriction and forage:concentrate ratio on digestibility, methane emission, and energy utilization by goats.[J]. Revista Brasileira de Zootecnia, 2016,45(12): 781-787