Effects of thiabendazole treatment on weight gains by Nebraska range cattle

The results of these studies indicate that a high percentage of Nebraska range cattle are infected with gastrointestinal parasites, but at a subclinical level of infection. However, significant differences were not observed in average daily gain between thiabendazole-treated range cattle and unmedicated controls in three of four field trials. In the three trials the average improvement in daily gain in animals receiving thiabendazole once averaged .01 lb greater than untreated controls. During a 120 day grazing period this improvement would not be sufficient to pay for the wormer or cost of additional labor.