Effect of Readily Available Carbohydrate and Roughage Source on Performance of Lambs and Steers Fed a Liquid Supplement

Two feeding experiments were conducted to evaluate the effect of readily available carbohydrate on performance of cattle and sheep fed low protein roughages and a liquid supplement. Exp. 1 consisted of two steer feeding trials to evaluate a basal diet (11.5% crude protein) consisting of 80% cottonseed hulls and 20% liquid supplement fed alone or supplemented with .454 kg per head daily of corn, wheat or roasted corn. The liquid supplement was a 32% crude protein supplement consisting primarily of cane molasses and urea. There were no differences (P>.05) among the cereal grain supplements in any of the performance, rumen or blood parameters studied. The basal diet promoted satisfactory growth and feed efficiency, and the results indicate that a low protein roughage, such as cottonseed hulls, may be fed successfully with a urea-based supplement. Exp. 2 consisted of two trials, each involving 30 individually fed lambs, to further evaluate the effect of various readily available carbohydrate sources on performance when low quality roughages were supplemented with a liquid supplement. Cornstarch, dextrose and roasted corn were fed at 5% of the diet with cottonseed hulls and liquid supplement or weathered fescue hay and liquid supplement in a 3 × 2 factorial arrangement of treatments. Similar performance, rumen volatile fatty acids (VFA) and blood urea nitrogen (BUN) values were observed for the various carbohydrate sources and there were no interactions (P>.05) observed between carbohydrate source and roughage source. Lamb fed cottonseed hull diets gained faster (P<.01), consumed more daily feed (P<.01) and had more favorable feed to gain ratios than those fed fescue hay diets.