The Food and Drug Administration has ruled that milk replacers may no longer be manufactured with the combination drug of neomycin and oxytetracycline, better known as neo-terramycin (NT), in its current 2:1 dosage. For many dairy producers, this will necessitate a change in the milk replacer they purchase for their calves. Approximately 55-65% of all milk replacers sold in the U.S. are manufactured with neo-terramycin.
There are two scenarios in which neo-terramycin can still be added to milk replacers:
- For continuous feeding, the total amount of the drug combination fed cannot exceed 0.05 to 0.1 milligrams per pound of body weight.
- For disease treatment, 10 milligrams per pound of bodyweight can be fed daily, but only for 7 to 14 days in calves up to 250 lbs.
The FDA also allowed that existing supplies of milk replacers manufactured with the 2:1dosage of NT can be sold until August 2010. “Most dairy producers who feed these medicated milk replacers are doing so as a preventive measure against scours,” explains Tom Earleywine, PhD, Land O’Lakes Animal Milk Products. “In our research comparing medicated and non-medicated milk replacers, we have not seen a consistent, significant advantage to adding medication, especially when calves are fed a higher plane of nutrition.”
Land O’Lakes Animal Milk Products has conducted 11 studies comparing nonmedicated milk replacers to those with neo-terramycin added at the traditional 2:1 ratio. In seven of those studies, calves responded with an improvement in gain when the medication was added. However, in the six trials where calves were fed a higher plane of nutrition, just two of the groups showed a growth response. There was no significant reduction in scours consistently seen in calves fed a medicated milk replacer.
“These findings are consistent with other research which has demonstrated an advantage in health for calves supplied a higher plane of nutrition,” Earleywine confirms. “Nutrition trumps medication every day, and the best preventive step we can take to protect our calves’ health is to supply them with a level of nutrition that will allow them to fight off disease challenges and achieve their full potential.”
In a recent study by the Cornell University College of Veterinary Medicine, a full potential plane of nutrition reduced the effect of disease due to Cryptosporidium parvum in neonatal dairy calves. Calves fed the high plane of nutrition maintained hydration, had faster resolution of diarrhea, grew more, and demonstrated greater feed efficiency than calves fed a conventional diet.