Effects of feeding a return chewing gum/packaging material mixture on performance and carcass characteristics of feedlot cattle.

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.