The aim of this study was to evaluate the chemical composition, digestibility, gas production kinetics and in vitro methane (CH₄) production of Urochloa brizantha cv. Marandu under two stocking methods over three consecutive stocking cycles. The stocking methods were (1) a fixed-time stocking cycle of 33 days (33-SC) with a 30-day rest period and a 3-day grazing period, and (2) a variable stocking cycle, with the end of the rest period when the canopy intercepted 95% of the light and a 3-day grazing period (95-LI). The average rest period was 24.5-day (standard deviation of 5.2-day) for 95-LI. The in vitro dry matter digestibility (IVDMD) was higher (p < .01) for 95-LI (646 g/kg) relative to 33-SC (628 g/kg). Crude protein concentration was higher (p < .01) for 95-LI (154 g/kg) relative to 33-SC (136 g/kg). The ADF (303 g/kg DM) and aNDF (623 g/kg) were higher (p < .01) for 33-SC compared to 95-LI (287 and 605 g/kg respectively). The gas production potential from non-fibrous carbohydrates was 9.4% higher for 33-SC. The in vitro CH₄ production per unit of degraded dry matter (DDM) was higher (p < .01) for 33-SC (19.9 CH₄ ml/g), compared to 95-LI (17.9 CH₄ ml/g). The 33-SC management resulted in rest periods that were too long for the time needed for optimal regrowth. The variable SC based on the 95-LI was more favourable, because it resulted in maximum yield of dry matter with improved forage nutritive value, while decreasing CH₄ yield.

中文翻译：

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Urochloa brizantha cv. 的营养价值和体外甲烷产量。固定时间或可变放养周期下的马兰杜

本研究的目的是评估Urochloa brizantha cv.的化学成分、消化率、产气动力学和体外甲烷 (CH ₄ ) 产量。Marandu 在连续三个放养周期的两种放养方法下。放养方法为（1）33天（33-SC）固定时间放养周期，休息30天，放牧3天；（2）可变放养周期，结束树冠拦截了 95% 的光线时的休息期和 3 天的放牧期 (95-LI)。95-LI 的平均休息时间为 24.5 天（标准差为 5.2 天）。 95-LI (646 g/kg) 的体外干物质消化率 (IVDMD)比 33-SC (628 g/kg)更高 ( p < .01)。粗蛋白浓度较高（p < .01) 95-LI (154 g/kg) 相对于 33-SC (136 g/kg)。 与 95-LI（分别为 287 和 605 g/kg）相比，33-SC的 ADF（303 g/kg DM）和 aNDF（623 g/kg）更高（p < .01）。33-SC 的非纤维碳水化合物产气潜力高 9.4%。与 95-LI (17.9 CH ₄ ml/g)相比 ，33-SC (19.9 CH ₄ ml/g)每单位降解干物质 (DDM) 的体外 CH ₄产量更高 ( p < .01 )。33-SC 管理导致休息时间过长，无法达到最佳再生所需的时间。基于 95-LI 的变量 SC 更有利，因为它导致最大的干物质产量和改善的草料营养价值，同时降低 CH ₄ 屈服。