Loerch S C, Fluharty F L
Department of Animal Sciences, Ohio Agricultural Research and Development Center, and The Ohio State University, Wooster 44691-4096, USA.
J Anim Sci. 1998 Mar;76(3):681-5. doi: 10.2527/1998.763681x.
In Trial 1, 108 crossbred steer calves (initial BW 295 kg) were allotted to 12 pens and used in a 186-d feedlot trial to determine the effects of increasing or decreasing roughage level on feedlot performance and carcass characteristics. Four dietary treatments were investigated: 1) 85% concentrate diet fed for 186 d, 2) 100% concentrate diet fed for 186 d, 3) 85% concentrate diet fed for 84 d followed by a 100% concentrate diet for the remaining 102 d, and 4) 100% concentrate diet for 84 d followed by an 85% concentrate diet for the remaining 102 d. Corn silage was added as roughage. During the first 84 d, level of dietary concentrate did not affect (P > .10) ADG. Steers switched to the 85% concentrate diet for the last 102 d had higher (P < .05) DMI than those fed the 100% concentrate diet; they did not exhibit an increase in ADG. Finishing phase feed efficiency was highest (P < .05) for steers continually fed 100% concentrate, lowest (P < .05) for steers continually fed 85% concentrate, and intermediate for steers whose concentrate level was switched during the trial. Carcass characteristics were not affected (P > .10) by concentrate level regimen. In Trial 2, 108 crossbred steer calves (initial BW 319 kg) were allotted to 12 pens and used in a 158-d trial to determine whether feedlot performance could be enhanced by manipulating roughage level and grain processing. Factors investigated were staged increases in concentrate level (70 to 85 to 100%) vs staged decreases in concentrate level (100 to 85 to 70%) and whole vs rolled high-moisture corn. Corn silage was added as roughage. Diet concentrate levels were changed on d 56 and 112. During the first 56 d, steers fed 70% concentrate diets grew 11% faster (P < .05) and consumed 19% more feed (P < .05) than those fed 100% concentrate diets. Steers fed rolled corn gained 8% faster (P < .06) and were 7% more efficient (P < .06) than those fed whole corn. During the last period (d 113 to 158), ADG was not affected (P > .10) by concentrate level or corn processing. Although increasing roughage during the feeding period increased feed intake in these trials, steer performance was not enhanced. Processing high-moisture corn did not affect feedlot performance.
在试验1中，108头杂交阉牛犊牛（初始体重295千克）被分配到12个围栏中，用于为期186天的饲养场试验，以确定提高或降低粗饲料水平对饲养场性能和胴体特性的影响。研究了四种日粮处理：1）85%精料日粮饲喂186天；2）100%精料日粮饲喂186天；3）85%精料日粮饲喂84天，随后在剩余的102天饲喂100%精料日粮；4）100%精料日粮饲喂84天，随后在剩余的102天饲喂85%精料日粮。添加玉米青贮作为粗饲料。在最初的84天里，日粮精料水平对平均日增重（ADG）没有影响（P>.10）。在最后102天转为85%精料日粮的阉牛犊牛的干物质采食量（DMI）高于饲喂100%精料日粮的阉牛犊牛（P<.05）；它们的平均日增重没有增加。持续饲喂100%精料的阉牛犊牛育肥期饲料效率最高（P<.05），持续饲喂85%精料的阉牛犊牛最低（P<.05），在试验期间精料水平转换的阉牛犊牛处于中间水平。胴体特性不受精料水平方案的影响（P>.10）。在试验2中，108头杂交阉牛犊牛（初始体重319千克）被分配到12个围栏中，用于为期158天的试验，以确定通过控制粗饲料水平和谷物加工是否可以提高饲养场性能。研究的因素包括精料水平的分阶段增加（70%至85%至100%）与精料水平的分阶段降低（100%至85%至70%）以及整粒与压片高水分玉米。添加玉米青贮作为粗饲料。日粮精料水平在第56天和第112天改变。在最初的56天里，饲喂70%精料日粮的阉牛犊牛比饲喂100%精料日粮的阉牛犊牛生长快11%（P<.05），采食量多19%（P<.05）。饲喂压片玉米的阉牛犊牛比饲喂整粒玉米的阉牛犊牛生长快8%（P<.06），效率高7%（P<.06）。在最后阶段（第113天至158天），平均日增重不受精料水平或玉米加工的影响（P>.10）。尽管在这些试验中，在饲养期增加粗饲料会增加采食量，但阉牛犊牛的性能并未提高。加工高水分玉米对饲养场性能没有影响。
