In this study differentenergy supplements for feedlot calves weaned at 80 days of age and averaging90 kg of body weight were evaluated. The following energy sources were used:corn grain (CG), rice bran (RB), soybean hulls (SH), corn grain + rice bran(CG + RB), soybean hulls + rice bran (SH + RB) or corn grain + soybean hulls(CG + SH). The diets were isonitrogenous (13% crude protein) with a 50:50 forage:concentrateratio. Sorghum silage (AG-2005E) constituted the forage portion of the diet.No significant differences were observed for dry matter intakes (DMI) expressedin kg (4.43 kg), per 100 kg of body weight (3.17%) or per unit of metabolicweight (109.10 g). Calves fed SH showed greater intake of NDF than those fedCG expressed in kg per day, per 100 kg of body weight and per unit of metabolicweight (2.41 kg, 1.73% and 59.46 g vs. 1.44 kg, 1.02% and 35.01 g, respectively).Daily digestible energy intake (DEI) was similar among treatments as well asthe average daily weight gain (.986 kg), feed conversion (4.52 kg DMI/kg ofweight gain) and energy efficiency (12.23 Mcal DEI/kg of weight gain). However,when compared by contrast analyses both diets with SH (SH and SH + RB) and bothdiets with CG (CG and CG + RB), it was observed that animals receiving dietswith soybean hulls consumed more DM than animals fed corn grain expressed eitherper 100 kg of body weight (3.28 vs. 3.06%) or per unit of metabolic weight- MW (112.67 vs. 105.59 g). It was also observed differences in DEI,being greater for diets containing corn grain (12.47 Mcal/day and .304 Mcal/MW)compared to those containing SH (11.67 Mcal/day and .288 Mcal/MW). Feed conversionimproved on calves fed diets with CG (4.21) than on those fed soybean hulls(4.80).
