Pre-weaned calf deworming study showed higher weight gain & increased value Deworming calves 2 months before weaning yielded about $13/head in added value 21 days after weaning25 August 2025 25 August 2025 3 minute read 3 minute read By: By: University of Arkansas North AmericaA recent Arkansas Agricultural Experiment Station study showed deworming calves about two months before weaning improved weight gain and added value for producers. Daniel Rivera, associate professor of animal science, said the weight gain translated to adding about $13 of value per head of cattle 21 days after weaning. “This can lead to reduced weight gain and other effects that are more difficult to measure, like immune response and vaccine efficacy. That translated to $10.25 in value added per head at weaning time and $12.80 per head 21 days after weaning. The pre-weaned dewormed calves still had a 5.5-pound weight advantage over those that did not get a deworming treatment before being weaned.