Bossuyt C V, Wittenberg K M, Crow G H
Department of Animal Science, University of Manitoba, Winnipeg, Canada.
J Anim Sci. 1996 Jun;74(6):1336-42. doi: 10.2527/1996.7461336x.
Two experiments were conducted to determine effects of fungal biomass (FB), as determined by glucosamine analysis, in alfalfa hay on intake and total tract digestion when fed to growing beef calves. Mycotoxins were not detected in hays used for these experiments. A feedlot trial using 40 weaned Angus calves (270.2 +/- 9.7 kg) showed that DM intake was not affected (P > .05) by FB content of the hay diets. No adaptation response was observed when animals with no previous exposure to molded feed were introduced to hay containing various levels of FB. Hematocrit and plasma cortisol levels were not affected (P > .05) by the presence of FB in the hay. Eight steers were used, in two 4 x 4 Latin squares, for intake and total tract digestibility determinations of two alfalfa hays having similar nutrient profiles but differ in FB concentrations. Hays were fed in long or chopped form. Level of FB did not affect (P > .05) DM intake or total tract DM digestibility. Neutral detergent fiber and ADF digestibilities were 5.4 and 3.7 percentage units higher (P < .05), respectively, for hay with a high vs low FB concentration. Forage chopping reduced (P < .05) DM, NDF, ADF, and CP digestibilities; the effect being similar for the two hay types tested. Results suggest that FB concentrations ranging from 2.9 to 5.5 mg/g of DM do not affect DM intake, however, nutrient digestion can be influenced by molding during field wilting or storage.
进行了两项试验，以确定通过氨基葡萄糖分析测定的苜蓿干草中真菌生物量（FB）对生长育肥牛犊采食量和全消化道消化率的影响。用于这些试验的干草中未检测到霉菌毒素。一项使用40头断奶安格斯犊牛（270.2±9.7千克）的饲养试验表明，干草日粮的FB含量对干物质采食量没有影响（P＞0.05）。当以前未接触过发霉饲料的动物被引入含有不同水平FB的干草时，未观察到适应反应。干草中FB的存在对血细胞比容和血浆皮质醇水平没有影响（P＞0.05）。使用8头阉牛，采用两个4×4拉丁方设计，对两种营养成分相似但FB浓度不同的苜蓿干草进行采食量和全消化道消化率测定。干草以长草或切碎形式饲喂。FB水平对干物质采食量或全消化道干物质消化率没有影响（P＞0.05）。高FB浓度干草的中性洗涤纤维和酸性洗涤纤维消化率分别比低FB浓度干草高5.4和3.7个百分点（P＜0.05）。切碎牧草降低了（P＜0.05）干物质、中性洗涤纤维、酸性洗涤纤维和粗蛋白的消化率；对两种测试干草类型的影响相似。结果表明，干物质中FB浓度在2.9至5.5毫克/克之间不会影响干物质采食量，然而，田间萎蔫或储存期间的霉变会影响养分消化。
