Effects of Ralgro at branding and Revalor-G at weaning on growth performance of steer calves

The objectives of this experiment were to determine (1) the effect of a Ralgro implant administered at 30 to 90 d of age on suckling-phase growth rate and weaning weight and (2) the effect of a Revalor-G implant at weaning on postweaning performance. A total of 194 suckling steer calves weighing 111 ± 25.6 kg at branding from 3 locations were used. Within location, steer calves were stratified by cow age and then randomly assigned to 2 experimental treatments: implanted with Ralgro (IMPL; n = 97) or no implant (NIMP; n = 97). At weaning, IMPL steers were reimplanted with Revalor-G. The steers were weighed at the time of branding, at weaning, after the preconditioning period, and after the stocker phase. Implanted steers gained 9 kg more (P < 0.01) BW between the branding and weaning dates compared with NIMP. This resulted in a 3.2% increase (P < 0.01) in actual weaning weight and a 6.6% increase (P < 0.01) in 134-d BW gain. One location yielded no difference (P > 0.5) in the preconditioning period; however, a 35.7% increase (P = 0.01) in IMPL ADG was recorded in the other 2 locations. In the wheat stocker phase, ADG was improved by 14.9% (P < 0.001) over NIMP. Ralgro growth-promoting implants remain an effective and economical method to increase performance of suckling steer calves, and the response is similar to research results published in the 1980s. Likewise, Ralgro followed by a Revalor-G implant allows for faster rates of BW gain and heavier final BW after weaning.