The addition of protein supplementation in a silvopastoral system can contribute to improved forage intake and digestibility. Our objective was to evaluate in vitro ruminal parameters, digestibility and gas production of Marandu palisadegrass [Urochloa brizantha (Hochst. ex A. Rich.) R. D. Webster] in a silvopastoral system and compare this to parameters obtained from diets with protein supplementation. Forage was sampled during the growing season (November to April) in 2016/17 and 2017/18. In vitro incubation treatments consisted of four levels of protein supplement (20% of crude protein; CP) in the diet (0.1, 0.2, 0.3 and 0.4 g/kg of body weight). The neutral detergent fibre, acid detergent fibre and indigestible neutral detergent fibre concentrations were highest in the first year. In the second year, CP concentration was 21% greater than in the first year. There was a linear increase for digestion rate, a quadratic effect for lag time and a linear decrease for average digestion time as supplementation levels were increased. The least lag time and digestion time occurred in the second year. There was no supplementation effect on ruminal pH, acetate and butyrate concentrations. Second‐year in vitro dry matter digestibility (IVDMD) was greater than in the first year. Increases in supplementation levels linearly enhanced IVDMD and reduced methane (CH₄) production. The inclusion of a protein supplement contributed to reduced CH₄ and increased volatile fatty acids production; therefore, we recommended the supplement inclusion of >0.28 g/kg of BW for animals grazing in well‐managed palisadegrass pastures.

中文翻译：

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畜牧牧草系统中Marandu palisadegrass（Urochloa brizantha）的体外瘤胃发酵参数和甲烷产生与蛋白质补充水平相关

牧草系统中添加蛋白质补充剂可有助于提高草料的摄入量和消化率。我们的目标是评估食牧系统中Marandu palisadegrass [ Urochloa brizantha（Hochst。ex A. Rich。）RD Webster]的体外瘤胃参数，消化率和产气量，并将其与从补充蛋白质的饮食中获得的参数进行比较。在2016/17和2017/18的生长季节（11月至4月）采样了草料。体外孵化处理包括饮食中四个水平的蛋白质补充剂（粗蛋白的20％； CP）（0.1、0.2、0.3和0.4 g / kg体重）。第一年中性洗涤剂纤维，酸性洗涤剂纤维和难消化的中性洗涤剂纤维浓度最高。在第二年，CP浓度比第一年高21％。随着添加量的增加，消化率呈线性增加，滞后时间呈二次效应，而平均消化时间呈线性下降。滞后时间和消化时间最少的是第二年。对瘤胃pH，乙酸盐和丁酸盐浓度没有补充作用。第二年体外干物质消化率（IVDMD）高于第一年。补充水平的增加线性增加了IVDMD并减少了甲烷（CH ₄）的产生。包含蛋白质补充剂有助于减少CH ₄并增加挥发性脂肪酸的产生。因此，我们建议对管理良好的木栅草牧场上放牧的动物补充体重> 0.28 g / kg体重。