Precision Feeding of Feedlot Calves Based on Phenotypic Production Profiles I. The Effect on Economic Important Production Parameters

Precision feeding feeder calves according to their production potential could improve economically important production traits. We report two experiments, in two separate locations where feeder calves were categorized into previously established production profiles (PP 1, PP 2, and PP 3). These production-profiled calves were then randomly allocated to a high-producing diet (HPD), medium-producing diet (MPD), or a low-producing diet (LPD). The findings of experiment 1 (<i>n</i> = 430) were used to adjust the formulation of the diets in experiment 2 (<i>n</i> = 104). The mixed modelling of economically important feedlot carcass growth traits was performed in order to evaluate the interactions between PP classification and diet. PP 3 was repeatedly outperformed in all production parameters (<i>p</i> < 0.01) by PP 1 and PP 2, irrespective of the diet. In experiment 1, PP 1 calves outperformed PP 2 and PP 3 calves; however, the HPD was insufficiently matched to their growth potential. In experiment 2 where the metabolizable energy was increased, PP 1 calves gained 23.0 kg more carcass (<i>p</i> = 0.05), at an improved carcass feed conversion of 0.91 kg/kg (<i>p</i> = 0.06), when compared to PP 2 calves on MPD. This is the first report demonstrating the feasibility of precision livestock feeding based on the predicted growth needs of incoming feeder calves as determined by production profiling.