Knoblich H V, Fluharty F L, Loerch S C
Department of Animal Sciences, Ohio Agricultural Research and Development Center and The Ohio State University, Wooster 44691, USA.
J Anim Sci. 1997 Dec;75(12):3094-102. doi: 10.2527/1997.75123094x.
In Trial 1, 161 Angus x Simmental crossbred steers (initial BW 305 +/- 1.0 kg) were used in a completely randomized design experiment to determine the effects of intake restriction and programmed gain on cattle performance and carcass composition and characteristics. Five feeding systems were tested using step-wise increases in programmed intake level. Initially steers were fed to gain 1.13 kg/d. Intake was then increased to achieve a gain of 1.36 kg/d. At the end of the feeding period, steers had ad libitum access to feed. Duration of intake restriction and the period of unrestricted intake was varied. Feeding steers at restricted intakes and then increasing daily gain by increasing feed intake using four different schedules all reduced (P < .05) daily feed intake and total feed intake compared with providing ad libitum access to feed throughout the trial. Furthermore, daily feed efficiency was increased (P < .05) by two of the feeding systems compared with offering ad libitum access to feed throughout the trial. The feeding system used did not affect (P > .10) quality grade of the carcasses. In Trial 2, 77 individually penned Angus x Simmental crossbred steers (initial BW 273 +/- 1.2 kg) were used to determine the effects of various feed intake restriction systems. For systems 1 through 4, multiple periods of restriction and realimentation were investigated; the duration and magnitude of restriction were varied. Feed intake was not restricted for steers in system 5. The feed restriction systems used in this experiment did not result in decreased total feed intake or changes in carcass composition as compared with offering ad libitum access to feed. Reducing total energy intake seems to be a prerequisite to altering feed efficiency of steers in limit-feeding systems.
在试验1中，161头安格斯×西门塔尔杂交阉牛（初始体重305±1.0千克）被用于一项完全随机设计试验，以确定采食限制和设定增重对牛的生产性能、胴体组成及特性的影响。采用逐步提高设定采食量水平的方式测试了五种饲养系统。最初，阉牛按每天增重1.13千克进行饲喂。随后采食量增加，以使日增重达到1.36千克。在饲喂期结束时，阉牛可自由采食。采食限制期和自由采食期的时长有所不同。与在整个试验期间让阉牛自由采食相比，采用四种不同方案对阉牛进行限饲然后通过增加采食量来提高日增重，均降低了（P < 0.05）日采食量和总采食量。此外，与在整个试验期间让阉牛自由采食相比，两种饲养系统提高了（P < 0.05）日饲料效率。所采用的饲养系统对胴体的质量等级没有影响（P > 0.10）。在试验2中，77头单独圈养的安格斯×西门塔尔杂交阉牛（初始体重273±1.2千克）被用于确定各种采食限制系统的影响。对于系统1至4，研究了多个限制和再饲喂阶段；限制的时长和幅度有所不同。系统5中的阉牛采食量不受限制。与让阉牛自由采食相比，本试验中使用的采食限制系统并未导致总采食量减少或胴体组成发生变化。在限量饲喂系统中，降低总能量摄入似乎是改变阉牛饲料效率的一个先决条件。
