New research from the University of Guelph looked at respiratory disease and two preventative treatment methods in calves after weaning. The study used 1,392 calves at a commercial heifer raising facility and compared treating calves with either 2 mL of a long-acting antibiotic (tulathromycin, marketed as Draxxin) or 5 mL of a short-acting antibiotic (oxytetracycline, marketed as Biomycin 200) at the time they were moved into group housing. Calves were weaned at six weeks of age and remained in individual pens for two weeks after weaning before being placed into groups.

This trial did not evaluate the impact of antibiotic treatment near weaning compared to no treatment. It was designed to compare two different treatment methods. In the six weeks following the move to group housing, 22 percent of calves treated with oxytetracycline and 13 percent of calves treated with tulathromycin developed respiratory disease. Among calves that had no respiratory disease before moving to group housing, calves treated with tulathromycin weighed more and were taller after six weeks in group housing than calves treated with oxytetracycline. Calves that were treated for respiratory disease before eight weeks of age did not respond differently to tulathromycin or oxytetracycline, perhaps because of damage due to respiratory illnesses earlier in life. Calves that experienced respiratory illness before eight weeks of age weighed 6.4 pounds less and were 0.24 inch shorter than healthy calves at 14 weeks of age. Respiratory illness during the first 6 weeks of group housing reduced 14-week body weight by 17.4 pounds and withers height by 0.5 inch.

Results of this study demonstrated the significant impact that respiratory disease can have on calves in the first three to four months of life and showed that tulathromycin may be used as an effective preventative treatment for calves during the high risk period after weaning. Long-acting antibiotic treatment at the time of group housing was more effective in calves that did not have a history of respiratory disease.

Source: Dairy Calf and Heifer Association