Effects of Next Enhance concentrations in finishing diets on performance and carcass characteristics of yearling feedlot cattle
A feedlot study evaluated the effects of NEXT ENHANCE® 300 (NEXT) essential oil concentration in finishing diets on yearling steer performance and carcass characteristics. Crossbred yearling steers (n =288; BW = 446 ± 23 kg) were utilized in a randomized block design experiment. Cattle were separated into 3 weight blocks (light, medium, and heavy), stratified by BW, and assigned randomly within strata to 36 pens. Pens were assigned randomly to one of four treatments with nine replications per treatment and eight steers per pen. Treatments consisted of feeding NEXT at concentrations of 0, 16.5, 33.1, and 49.6 mg/kg of diet DM. Light, medium, and heavy blocks consisted of 3, 4, and 2 replications, respectively. Monensin and tylosin were provided in all treatments at 360 and 90 mg/steer daily, respectively. Steers were fed a common basal diet consisting of 54% dry-rolled corn, 25% wet distillers grains plus solubles, 15% corn silage, and 6% supplement (DM basis). Steers in the medium and heavy blocks were fed for 98 d, while steers in the light block were fed for 118 d. Animal performance and carcass characteristics were analyzed using the MIXED procedure of SAS with pen as the experimental unit. Increasing NEXT concentration in the diet had no effect on DMI, ADG, or G:F (P > 0.59; linear or quadratic). Hot carcass weight, fat thickness, and calculated yield grade were not affected (P > 0.21; linear or quadratic) by NEXT concentration. As NEXT concentration increased, LM area tended (P= 0.06) to decrease quadratically. Greatest LM area were observed when steers were fed 0 or 49.6 mg/kg NEXT, while feeding 33.1 mg/kg NEXT produced the smallest LM area. These data suggest that feeding increasing concentrations of NEXT had little impact on feedlot performance of large yearlings.
Keywords: beef cattle, essential oil, feedlot performance