Hubbell D S, Goetsch A L, Galloway D L, Forster L A, Sun W, Harrison K F
University of Arkansas, Fayetteville 72701.
Arch Tierernahr. 1992;42(1):79-92. doi: 10.1080/17450399209428532.
Beef cattle consuming bermudagrass hay were not supplemented or received a limited amount of ground corn alone or with a mix of protein meals to determine influences of concentrate supplementation on digestion and performance when the ionophore lasalocid (200 mg daily) was given. With limited feed intake, supplement treatment did not change the acetate to propionate shift in beef cows occurring with lasalocid (P < 0.06). Lasalocid did not affect sites of digestion of organic matter or nitrogen with any supplement treatment. However, lasalocid decreased (P < 0.10) ruminal digestion of neutral and acid detergent fibre. Live-weight gain by growing beef calves ingesting bermudagrass hay ad libitum was higher (P < 0.05) with than without supplementation and tended (P < 0.12) to be greater for corn plus protein meals than for corn alone. Lasalocid did not affect or interact with supplement treatment in feed intake or live-weight gain of heifers (236 kg; no growth stimulant) or steers (237 kg; treated with 200 mg progesterone and 20 mg estradiol benzoate). Lasalocid at 200 mg daily did not improve digestion characteristics or influence performance by beef cattle consuming a Basal diet of bermudagrass hay. Further, effects of lasalocid were not modulated by supplementation with concentrate, concentrate type or sex or growth stimulant usage.
给食用百慕大干草的肉牛不进行补饲，或仅单独给予少量的玉米粉，或搭配蛋白质饲料，以确定在添加离子载体拉沙洛西（每日200毫克）时，补饲精料对消化和生产性能的影响。在采食量有限的情况下，补饲处理并未改变拉沙洛西作用下肉牛体内乙酸与丙酸的转化（P < 0.06）。在任何补饲处理中，拉沙洛西均未影响有机物或氮的消化部位。然而，拉沙洛西降低了（P < 0.10）瘤胃中中性洗涤纤维和酸性洗涤纤维的消化率。随意采食百慕大干草的生长肉牛犊，补饲组的体重增加更高（P < 0.05），且玉米加蛋白质饲料组的增重往往（P < 0.12）高于仅喂玉米组。拉沙洛西对小母牛（236千克；未使用生长促进剂）或阉牛（237千克；用200毫克孕酮和20毫克苯甲酸雌二醇处理）的采食量或体重增加没有影响，也未与补饲处理产生相互作用。每日200毫克的拉沙洛西并不能改善食用以百慕大干草为基础日粮的肉牛的消化特性，也不影响其生产性能。此外，拉沙洛西的作用不受精料补饲、精料类型、性别或生长促进剂使用的调节。
