Campbell C P, Marshall S A, Mandell I B, Wilton J W
Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
J Anim Sci. 1992 Mar;70(3):894-903. doi: 10.2527/1992.703894x.
Ten 394-kg, ruminally fistulated Hereford steers were used in a replicated 5 x 5 Latin square design to evaluate the effects of source and level of dietary NDF on chewing activities during eating and rumination. Diets contained 62 to 64% TDN and included 1) 80% pelleted concentrate (control; contained ground grains, fibrous byproducts, molasses, and protein, vitamin, and mineral supplements; 36% NDF, 16% CP) and 20% long timothy hay (67% NDF, 8% CP), 2) 80% control concentrate and 20% alfalfa cubes (56% NDF, 15% CP), 3) 90% control concentrate and 10% alfalfa cubes, 4) a completely pelleted diet using corn cobs as the primary NDF source (40% NDF, 17% CP), and 5) 80% textured (coarse instead of ground grains; 42% NDF, 15% CP) concentrate and 20% hay. Diets were formulated to be similar in NDF content, and dietary protein satisfied NRC recommendations. Chewing during eating did not differ (P greater than .10) between diets containing supplemental roughage but decreased (P less than .001) with the corn cob diet. Rumination chewing decreased (P less than .001) with the corn cob and cube diets. The number of chews per day during eating corrected for NDF intake/BW.75 decreased (P less than .05) in the corn cob diet. Rumination periods and duration increased and latency before rumination decreased in hay diets. Steers fed the corn cob diet tended to be more (P less than .10) consistent in time spent eating across 4-h intervals than steers fed the traditional diet. Replacement of long hay with the completely pelleted corn cob diet decreased rumination activity.
选用10头体重394千克、瘤胃有瘘管的赫里福德阉牛，采用重复的5×5拉丁方设计，以评估日粮中性洗涤纤维（NDF）来源和水平对采食和反刍期间咀嚼活动的影响。日粮含有62%至64%的总可消化养分（TDN），包括：1）80%的颗粒精料（对照；包含磨碎谷物、纤维副产品、糖蜜以及蛋白质、维生素和矿物质补充剂；36% NDF，16%粗蛋白）和20%的长提摩西干草（67% NDF，8%粗蛋白），2）80%对照精料和20%苜蓿块（56% NDF，15%粗蛋白），3）90%对照精料和10%苜蓿块，4）一种以玉米芯作为主要NDF来源的完全颗粒日粮（40% NDF，17%粗蛋白），以及5）80%的压片（粗粒而非磨碎谷物；42% NDF，15%粗蛋白）精料和20%干草。日粮在NDF含量方面配制得相似，日粮蛋白质满足美国国家研究委员会（NRC）的建议。含补充粗饲料的日粮之间采食时的咀嚼情况无差异（P大于0.10），但玉米芯日粮的咀嚼情况有所下降（P小于0.001）。反刍咀嚼在玉米芯和块状日粮组有所下降（P小于0.001）。采食时每采食NDF摄入量/体重0.75校正后的每日咀嚼次数在玉米芯日粮组下降（P小于0.05）。干草日粮组的反刍周期和持续时间增加，反刍前的延迟时间减少。采食玉米芯日粮的阉牛在4小时时间段内采食所花费的时间比采食传统日粮的阉牛更趋于一致（P小于0.10）。用完全颗粒状的玉米芯日粮替代长干草会降低反刍活动。
