Light competition increases and plants’ growth pattern change to optimize light utilization when the leaf area index increases. It has been previously shown that using 95% canopy light interception (LI) as a grazing frequency criterion resulted in a greater proportion of leaves and a lower proportion of stem. The objective of the study was to characterize the forage production, morphological composition and nutritive value of Panicum maximum cv Mombaça. The experiment was carried out during summer, autumn–winter and spring. Treatments corresponded to combinations of two pre-grazing conditions (95% and maximum LI at pre-grazing; LI95% and LIMax, respectively) and two post-grazing heights (PGHs; 30 and 50 cm). The statistical design was a randomized complete block, with a 2 × 2 factorial arrangement. Swards managed with LI95% had greater proportions of leaves and lower proportions of stems compared to LIMax. Leaf proportion was lower during autumn–winter compared to summer and spring. The LI95% had greater crude protein (CP) and digestibility (IVOMD), and lower acid detergent fibre (ADF) concentrations than LIMax. The 50 cm PGH pastures had greater CP content and IVOMD, and lower ADF content than 30 cm PGH pastures. Lower IVOMD was observed during autumn–winter than summer and spring. The variability observed on morphological characteristics was primarily associated with seasonality, whilst the nutritive value was primarily affected by grazing management. The pre-grazing target of LI95% combined with 50 cm PGH was the combination that resulted in an increased proportion of leaves, decreased stems in basal stratum and the greatest nutritive value of the produced forage.

中文翻译：

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不同轮牧策略管理蒙巴萨草的营养价值和形态特征

当叶面积指数增加时，光竞争增加，植物生长模式改变以优化光利用。先前已经表明，使用 95% 的冠层光拦截 (LI) 作为放牧频率标准会导致更大比例的叶子和更低比例的茎。该研究的目的是表征牧草的产量、形态组成和营养价值。大麦穗简历蒙巴萨。试验在夏季、秋冬和春季进行。处理对应于两种放牧前条件的组合（放牧前的 95% 和最大 LI；LI95%和李最大限度，分别）和两个放牧后高度（PGH；30 和 50 厘米）。统计设计是一个随机完整区组，采用 2 × 2 因子排列。使用 LI 管理的 Swards95%与 LI 相比，叶子的比例更高，茎的比例更低最大限度. 与夏季和春季相比，秋冬季的叶片比例较低​​。李95%与 LI 相比，粗蛋白 (CP) 和消化率 (IVOMD) 更高，酸性洗涤纤维 (ADF) 浓度更低最大限度. 与 30 cm PGH 牧场相比，50 cm PGH 牧场的 CP 含量和 IVOMD 更高，而 ADF 含量更低。秋冬季比夏季和春季观察到较低的 IVOMD。在形态特征上观察到的变异性主要与季节性有关，而营养价值主要受放牧管理的影响。LI的放牧前目标95%与 50 cm PGH 相结合是导致叶比例增加、基层茎减少和所生产草料的最大营养价值的组合。