By Travis Peardon, PAg, Livestock & Feed Extension Specialist, Outlook
Ionophores are a beneficial feed additive that should be used when backgrounding calves. Ionophores provide protection against coccidiosis, improve feed efficiency and stabilize the rumen environment by reducing the incidence of bloat. The three ionophores approved for use in Canadian feedlots are Bovatec©, Posistac© and Rumensin©. Rumensin is the most common ionophore available. Rumensin is approved for two different diet concentrations. Rumensin should be fed at 22 mg/kg in the complete diet as an aid in prevention of Coccidiosis. Rumensin should be fed at 33 mg/kg in the complete diet for improved efficiency in beef cattle. Bloat control will be achieved at both feeding levels.
I recently worked with a producer on backgrounding rations that contained a screenings pellet with Rumensin as an ingredient. The producer had the option of buying the pellet with three different levels of Rumensin, R33 (33 mg/kg), R42 (42 mg/kg) or R56 (56 mg/kg). So, the question was: what level of Rumensin is required in the ration to achieve our goals? In this case, the producer was primarily concerned about coccidiosis control which would require a total ration concentration of 22 mg/kg. The ration in this case included 11 pounds of grass/alfalfa hay and seven pounds of pellets.
The first step in this process was to convert our total amount fed into kilograms. Eighteen pounds total feed/2.2 lbs/kg = 8.18 kg of total feed. We know that we need 22 mg/kg of Rumensin in order to achieve coccidiosis control. Therefore, we need 8.18 kg of total feed x 22mg/kg of Rumensin = 180mg of Rumensin in each calf’s diet. Since we are feeding seven pounds or 3.2 kg of pellets a day we can then figure out what level of Rumensin is needed in the pellets. 180 mg/kg of Rumensin/3.2 kg of pellets = 56 mg/kg. Therefore, we need to purchase the pellets with the R56 level of Rumensin.
This calculation must be performed each time a feed is used that contains Rumensin. It is important to remember that different ionophores have specific feeding recommendations. Feeding at too low of a level is a waste of resources and can leave animals at risk of bloat and coccidiosis. Every year I hear of producers with coccidiosis outbreaks in their backgrounding animals. These cases almost always result in severe loss of animals. Bloat is also a concern with backgrounding calves, especially as they adapt to high-grain diets. Ionophores fed at proper levels are an affordable way to protect yourself from these risks.
For More Information Contact, Travis Peardon 306-867-5504 or your nearest Livestock and Feed Extension Specialist.