Implants and ionophores (i.e., Rumensin) are both proven technologies for stocker cattle production. However, some producers have asked what happens when these technologies are "stacked" together. Do these technologies retain their full efficacy when they are used simultaneously? Theoretically, the answer is "yes" because these technologies have different biological modes of action.
To demonstrate the effects of stacking these technologies, the Noble Research Institute conducted an experiment in 2012. In this experiment, steers grazed cereal rye pasture at the Noble Research Institute's Red River Demonstration Farm for 84 days. Steers received one of three supplementation programs: plain white SALT blocks (SALT); non-medicated mineral blocks (MIN); or identical mineral blocks with added Rumensin (R-MIN). Further, half of the steers in each supplement treatment group were implanted (Component TE-G with Tylan) and the other half were not implanted. These combinations allowed us to evaluate the effect of stacking the implant and ionophore technologies.
As expected, the implant dramatically improved average daily gain (ADG) (Figure 1). The R-MIN supplement also improved ADG compared to SALT. The non-medicated mineral block was intermediate in ADG. Importantly, we found no decrease in effectiveness of either the implant or the Rumensin when the two were used simultaneously. We calculated that stacking the two technologies significantly improved net return over the control system (no implant and SALT supplementation).
To determine block intake, we weighed the blocks in each paddock every week (Figure 2). Apparent intake was least for SALT blocks and greatest for the non-medicated mineral blocks. Overall, intake of the blocks was good, averaging about 3 ounces per steer per day. Adding Rumensin to the mineral blocks reduced intake of the block, which saved money and improved performance of the cattle. In this study, we followed the label feeding instructions which were to offer blocks at the rate of one block per five steers and to replace the blocks when 80 percent of the block disappeared.
Consider using both implants and ionophores to increase ADG of stocker cattle. Both management practices are profitable and work well together. If mineral blocks are more convenient than loose mineral, you can expect adequate intake if you follow the label directions.
Disclosure: This research was sponsored by Ridley Block Operations and Elanco Animal Health.