Rouquette F M, Griffin J L, Randel R D, Carroll L H
J Anim Sci. 1980 Sep;51(3):521-5. doi: 10.2527/jas1980.513521x.
Two trials were conducted to determine the influence of monensin on live weight gain and efficiency of forage utilization of calves grazing Bermudagrass. In trial 1, 32 calves, weaned at an average age of 238 days and 250 kg, were grazed on "Coastcross I" Bermudagrass from July 20 to October 13. Eight steers and eight heifers were randomly assigned to one of two treatments: 200 mg monensin/head/day or 0 mg monensin/head/day fed in a .01 kg/head/day diet of pelletized 14% protein feed. Both groups were stocked at 15.3 head/ha. Monensin-fed calves gained .52 kg/head/day, while the control-fed calves gained .42 kg/head/day (P < .10). Average daily gains (ADG) of steers (.54 kg) were greater (P < .05) than those of heifers (.40 kg). Forage to gain ratio estimates were 15:1 and 19:1 for calves on monensin and control paddocks, respectively. In trial 2, 48 steer calves, averaging 265 days of age and 260 kg, were randomly assigned to each of two replicates of the following grazing treatments: common Bermudagrass only (P), Bermudagrass + .91 kg/head/day 14% protein feed (PF) or Bermudagrass + .91 kg/head/day feed + 200 mg monensin/head/day (PFM). ADG were .45, .47 and .68 kg for steers fed P, PF and PFM, respectively. The monensin-fed calves showed a 45% improvement in ADG (P < .05). Estimated forage to gain ratios for calves fed P, PF and PFM were 20:5:1, 19:1 and 13:1, respectively. The use of 200 mg monensin/head/day improved calf gains by 23 to 45% and increased estimated feed efficiencies by 21 to 36% on Bermudagrass pastures. The improvement in gain for heifers fed monensin was 28.6%, while steers gained 18.4% more when fed monensin.
进行了两项试验，以确定莫能菌素对放牧百慕大草的犊牛体重增加和饲料利用效率的影响。在试验1中，32头犊牛平均在238日龄、体重250千克时断奶，于7月20日至10月13日在“海岸杂交一号”百慕大草上放牧。8头公牛和8头母牛被随机分配到两种处理之一：每天每头饲喂200毫克莫能菌素或每天每头饲喂0毫克莫能菌素，混入0.01千克/头/天的14%蛋白质颗粒饲料中。两组的饲养密度均为15.3头/公顷。饲喂莫能菌素的犊牛日增重为0.52千克/头，而对照饲喂的犊牛日增重为0.42千克/头（P < 0.10）。公牛的平均日增重（ADG）为0.54千克，高于母牛的0.40千克（P < 0.05）。莫能菌素处理牧场和对照牧场犊牛的料肉比估计分别为15:1和19:1。在试验2中，48头平均265日龄、体重260千克的公牛犊被随机分配到以下放牧处理的两个重复组中：仅普通百慕大草（P）、百慕大草 + 0.91千克/头/天的14%蛋白质饲料（PF）或百慕大草 + 0.91千克/头/天的饲料 + 200毫克莫能菌素/头/天（PFM）。饲喂P、PF和PFM的公牛的ADG分别为0.45、0.47和0.68千克。饲喂莫能菌素的犊牛ADG提高了45%（P < 0.05）。饲喂P组、PF组和PFM组犊牛的估计料肉比分别为（20:5:1）、19:1和13:1。在百慕大草牧场上，每天每头使用200毫克莫能菌素可使犊牛增重提高23%至45%，并使估计的饲料效率提高21%至36%。饲喂莫能菌素的母牛增重提高了28.6%，而公牛饲喂莫能菌素时增重提高了18.4%。
