If you've written a check to your friendly local animal health supply house or looked at a closeout sheet on a set of high-risk calves, you know sickness reduces profitability. But how much and to what extent it affects your banker's heartburn might be surprising.

Not only do you have the medicine cost, but sickness reduces average daily gain (ADG), carcass price and gross income, according to Clay Mathis, New Mexico State University Extension livestock specialist.

Mathis and his colleagues from New Mexico and Texas recently published data on 813 steers from 48 New Mexico ranches enrolled in the New Mexico Ranch to Rail program from 2000 to 2003. Of those calves, 22% received medical treatment, with 78.5% of that total treated only once and 21.5% treated two or more times.

“Results of the analysis indicate the steers that remained healthy — never pulled and treated for sickness — had greater ADG with fewer days on feed than steers that were treated,” Mathis says. “And steers treated only once were on feed for fewer days and tended to have higher ADG than steers treated two or more times.”

On the rail, the differences grew smaller, largely because the treated steers had more days on feed. No differences in fat thickness, marbling score, ribeye area or yield grade were observed. However, healthy steers tended to have heavier carcasses than treated steers.

Combining the difference in gross income and medicine cost between healthy and treated steers indicates a potential net return of $95/head to healthy steers, Mathis says (Table 1). And that doesn't account for differences in feed costs for longer days on feed for the sick steers.

Nor is that figure a fluke. It tracks closely with data from the Texas Ranch to Rail North program conducted from 1992 to 2001. Those data showed the average profit difference between healthy vs. sick steers over nine years was $91.88.

What's more, Mathis says the findings suggest the value of a calf headed for a feedyard is dependent on its likelihood of getting sick. In fact, looking at the figures generated from the Texas Ranch to Rail program, the average added value of a healthy calf was $15.49/cwt.

In other words, if you know a calf is going to get sick, you need to pay $15.49/cwt. less for that calf in order to keep pace economically with its pen mate that never sees the hospital.