431 Late-Breaking: The effects of including cotton byproducts in a finishing ration on the performance carcass characteristics and fecal characteristics of crossbred beef steers

摘要

Increased cotton production in the Southwest U.S. has increased the availability of cotton byproducts for use in cattle diets. The objective of this experiment was to evaluate the inclusion of cotton byproducts in feedlot finishing rations on the performance, carcass characteristics, and fecal characteristics of steers. Crossbred beef steers (n = 64; BW = 318 ± 12.3 kg) were assigned to 1 of 2 experimental treatments in a randomized complete block design (8 pens/treatment; 4 steers/pen). Treatments included a control (CON) diet (7% hay, 15% wet corn gluten feed, 67% rolled corn, 5% liquid supplement) and a cotton byproduct (CTN) diet (7% gin trash, 15% whole cottonseed, 72% rolled corn, 5% water). Both diets included 0.75% urea and 5% dry supplement. The CTN steers tended to have a heavier final BW (P = 0.09) and greater ADG (P = 0.08). Over the entire feeding period, DMI was greater for CTN steers than CON steers (P = 0.04) with no difference in G:F between treatments (P = 0.89). The CTN steers had heavier HCW (P = 0.02) and greater fat thickness (P = 0.03) than CON steers, but marbling score and REA were not different between treatments (P ≥ 0.64). Steers fed the CON diet tended to have a lower YG (P = 0.07), less KPH fat (P = 0.09), and lower dressing percentage (P = 0.10) than CTN steers. Liver scores did not differ between treatments (P ≥ 0.17). Fecal scores were lower for CTN steers on d 56 (P = 0.03) and fecal pH tended to be higher for the CTN steers on d 28 (P = 0.09), but neither differed during other periods (P ≥ 0.18). These results suggest that cotton byproducts can be used in feedlot rations without adverse effects on performance or carcass characteristics.