In spite of high cost, longer-acting, injectable therapeutic antimicrobials such as Draxxin can extend the window of treatment duration, thereby reducing the incidence and severity of bovine respiratory disease, according to K-State researchers. They also note that use of feed-based metaphylaxis programs, such as therapeutic administration of multiple 5-day pulses of Aureomycin in conjunction with an injectable metaphylaxis program may be a cost-effective way to improve bovine respiratory disease therapy without having to physically handle and stress cattle.

To evaluate these programs, the researchers conducted a 55-day receiving study at the Kansas State University Beef Stocker Unit to determine the response of high-risk stocker calves to concurrent metaphylaxis with Draxxin and Aureomycin. All cattle were sourced from an order buyer in Tennessee, and cattle were received over three consecutive days. Upon arrival, all calves were weighed, tagged, mass medicated with Draxxin at 1.1 mL per 100 pounds of bodyweight.

Diets included one of the following three treatments:

  • No top-dress pellets (control).
  • Feed top-dressed with Aureomycin-containing pellets (10 mg chlortetracycline per pound of body weight) on days 8 to 12, 14 to 18, 20 to 24, and 26 to 30 post-arrival.
  • Feed top-dressed with Aureomycin pellets on days 0 to 4, 6 to 10, 12 to 16, 18 to 22, and 24 to 28 followed by 25 days of administration of AS-700, which provided 350 mg/head per day of both chlortetracycline and sulfamethazine.

The researchers found no significant differences among treatments in the percentage of steers treated once, twice, or one or more times for bovine respiratory disease. There also were no significant differences in daily gain, daily dry matter intake, or feed efficiency among the three treatments.

The researchers concluded that in this study there was no benefit of feeding Aureomycin for four 5-day periods after receiving when calves were mass medicated with Draxxin upon arrival.

More information.