Leaf tissue flows and defoliation patterns of Alexandergrass grazed by heifers receiving energy supplement

ABSTRACT. The study was carried out to evaluate defoliation patterns and to quantify leaf tissue flows in Alexandergrass (Urochloa plantaginea (Link.) Hitch) grazed by beef heifers receiving whole rice bran in three levels of supplementation (0, 0.5 and 1 % of body weight). A rotational stocking grazing method and two area replications were utilized. The experimental design was completely randomized following a repeated measure arrangement. The supply of rice bran to heifers grazing Alexandergrass increased the stocking rate by 13%. Regardless of the feeding system, the heifers grazed the expanding leaf blades in the top stratum of the canopy more frequently compared to other types of leaf. Leaf tissue flows, leaf blade intake and grazing intensity have not been changed by supplement fed.

摘要：本研究旨在评估臂形草（Alexandergrass，Urochloa plantaginea (Link.) Hitch）的叶组织移除模式，并量化饲喂3个全脂米糠补充水平（占体重0、0.5%与1%）的肉用青年母牛采食该草时的叶片组织流量。试验采用轮牧放牧法，设置2个区域重复，实验设计为结合重复测量的完全随机设计。为采食臂形草的青年母牛补充米糠可使放牧载畜率提升13%。无论饲喂方案如何，青年母牛均更频繁地采食冠层顶层的展开叶片，相较于其他类型叶片。补充饲喂未对叶片组织流量、叶片采食量及放牧强度产生显著影响。