Wolf B W, Berger L L, Fahey G C
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
J Anim Sci. 1996 Nov;74(11):2559-65. doi: 10.2527/1996.74112559x.
Seventy-two Simmental-cross growing steers (219 +/- 2.4 kg initial BW) were used in a randomized complete block design to evaluate the effects of feeding a return chewing gum/packaging material mixture (G/P) on feedlot performance, carcass characteristics, sensory attributes of meat, and mineral content of beef liver and muscle. Animals were allotted by weight to 12 pens (six/pen). Each pen was assigned one of three dietary treatments: 1) 0% G/P (control), 2) 20% G/P, or 3) 30% G/P (% G/P on a DM basis). Steers were fed their respective diets for an 84-d growing phase and a 112-d finishing phase. The G/P replaced corn silage and corn in the growing and finishing phases, respectively. Eighteen steers (six/treatment) were randomly selected for slaughter at the end of the finishing phase, and carcass measurements, sensory attributes of meat, and mineral content of liver and longissimus muscle were measured. During the growing phase, steers fed G/P-containing diets had improved (P < .01) daily DMI, ADG, and gain:feed ratios (G:F) compared with controls. However, due to compensatory gain and the fact that G/P replaced corn in the finishing phase, control steers had increased (P < .01) ADG and improved (P < .05) G:F vs steers fed G/P-containing diets. Over the entire study (growing and finishing phases) steers fed diets containing G/P and the control had similar performance. Amount of G/P in the diet had no effect (P > .05) on carcass characteristics. Steaks from steers fed 20% G/P had improved (P < .01) juiciness compared with steaks from steers fed 30% G/P; no other sensory attributes were affected. Aluminum, zinc, and barium content of longissimus muscle and liver were within the normal expected ranges for all treatments. These data indicate that G/P can safely replace at least 30% of growing and finishing diets without impairing feedlot performance or carcass merit.
选用72头西门塔尔杂交生长阉牛（初始体重219±2.4千克），采用随机完全区组设计，以评估饲喂回收口香糖/包装材料混合物（G/P）对育肥性能、胴体特性、肉的感官属性以及牛肉肝脏和肌肉矿物质含量的影响。按体重将动物分配到12个围栏（每个围栏6头）。每个围栏分配三种日粮处理之一：1）0% G/P（对照），2）20% G/P，或3）30% G/P（基于干物质的G/P百分比）。阉牛在84天的生长阶段和112天的育肥阶段饲喂各自的日粮。在生长阶段和育肥阶段，G/P分别替代了青贮玉米和玉米。在育肥阶段结束时，随机选择18头阉牛（每个处理6头）进行屠宰，并测量胴体指标、肉的感官属性以及肝脏和背最长肌的矿物质含量。在生长阶段，与对照组相比，饲喂含G/P日粮的阉牛日干物质采食量（DMI）、平均日增重（ADG）和增重：饲料比（G:F）有所改善（P < 0.01）。然而，由于补偿生长以及G/P在育肥阶段替代了玉米，对照阉牛的ADG有所增加（P < 0.01），G:F有所改善（P < 0.05），与饲喂含G/P日粮的阉牛相比。在整个研究期间（生长阶段和育肥阶段），饲喂含G/P日粮的阉牛和对照阉牛的性能相似。日粮中G/P的含量对胴体特性没有影响（P > 0.05）。与饲喂30% G/P阉牛的牛排相比，饲喂20% G/P阉牛的牛排多汁性有所改善（P < 0.01）；其他感官属性未受影响。所有处理的背最长肌和肝脏中的铝、锌和钡含量均在正常预期范围内。这些数据表明，G/P可以安全地替代至少30%的生长和育肥日粮，而不会损害育肥性能或胴体品质。
