Ingestive behavior of steers finished on soybean hull and/or white oat grain

Abstract The objective of this research was to measure the ingestive behavior of steers finished exclusively with concentrate containing soybean hulls (ground) and/or white oat grain.We used 32 steers with Charolais or Nellore predominance.The animals were randomly distributed in the treatments, blocked according to genetic predominance, and allocated in individual pens. Diets were isonitrogenous, being the treatments: Soybean hulls; White oat grain or the Mixture (equal parts), plus limestone and protein nucleus. Steers that received the diet based on soybean hulls remained more time in idle compared to the ones that received the mixture, and these remained more time in idle than the steers that received the diet based on white oat grain. Steers that received the diet based on soybean hulls ruminated less time than the steers fed the mixture, and these less time than those fed white oat grain. Exclusively concentrate diets based on soybean hulls although presenting high soluble fiber content in neutral detergent, are not sufficient to promote an appropriate ingestive behavior of steers of Charolais or Nelore racial predominance.

摘要 本研究旨在测定仅以添加粉碎大豆皮（soybean hulls）和/或白燕麦粒（white oat grain）的精料（concentrate）育肥的阉牛的采食行为（ingestive behavior）。试验选取32头以夏洛来牛（Charolais）或内洛尔牛（Nellore）为遗传优势的阉牛，按遗传优势进行区组划分后随机分配至各处理组，单栏饲养。试验日粮均为等氮日粮（isonitrogenous diet），处理组设置如下：大豆皮组、白燕麦粒组，以及按等比例混合大豆皮与白燕麦粒组，三组日粮均添加石灰石（limestone）与蛋白质预混核心料（protein nucleus）。结果表明，饲喂大豆皮日粮的阉牛静息时长显著高于饲喂混合日粮的阉牛，而饲喂混合日粮的阉牛静息时长又显著高于饲喂白燕麦粒日粮的阉牛。反刍时长方面，饲喂大豆皮日粮的阉牛反刍时长显著短于饲喂混合日粮的阉牛，后者反刍时长又显著短于饲喂白燕麦粒日粮的阉牛。研究显示，尽管以大豆皮为主要原料的全精料日粮中性洗涤剂可溶性纤维含量较高，但仍不足以维持以夏洛来牛或内洛尔牛为遗传优势的阉牛的适宜采食行为。