A new FDA approval allowing the use of Aureomycin (chlortetracycline) and Bovatec (lasalocid sodium) in the same cattle feed is expected to help producers optimize weight gain and feed efficiency while controlling anaplasmosis, coccidiosis and the leading causes of bacterial enteritis and pneumonia.
In an 82-day trial conducted by Kansas State University, grazing steers fed Aureomycin (350 mg per head daily) and Bovatec (30 grams per ton of feed) achieved an average daily gain that was 10% higher than unmedicated controls (2.64 pounds of gain per day vs. 2.40).
"As a general rule, we found that using the two medications together increased gain by 0.20 to 0.30 pound per day," reports Gerry Kuhl, a retired cattle specialist from KSU who did some of the trial work with the combination with colleague Frank Brazle.
Twig Marston, a nutritionist and extension beef specialist at KSU, notes that Aureomycin and Bovatec have different yet complementary modes of action, which may account for the excellent performance seen when the two medications are used in the same feed.
"The two products really complement each other very well," he says. "Bovatec works in the rumen microflora to improve intestinal health and allow animals to utilize the energy of feedstuffs more efficiently," he explains. "That, in turn, produces a healthier animal, one that can respond better to antibiotic treatments."
Kuhl thinks the new Aureomycin-Bovatec combination may make producers less dependent on labor-intensive injectable antibiotics and make it easier to protect the herd from respiratory problems.
"In the past, if your animals were on Bovatec or another ionophore, you had to use an injectable antibiotic for managing respiratory disease," he says. "That was a real struggle, particularly in grazing situations and some growing and finishing operations. The Aureomycin-Bovatec combination changes that scenario dramatically, to the point where I think some consulting nutritionists will now consider Bovatec because it can be fed with Aureomycin."
Kuhl and Marston also expect the Aureomycin-Bovatec combination to be useful in any situation where cattle are grazing on native and improved grasses or wheat pasture.
"I think the combination has the potential to really help cow-calf producers and stocker operators considerably on a wide variety of forages," Marston says. "Certainly, it will be a good tool during adverse weather, when respiratory problems are more prevalent."