A clinical trial to evaluate the effects of flumethrin or ivermectin treatment on hemoparasites, gastrointestinal parasites, conception and daily weight gain in a dairy farm in Japan

A clinical trial was performed to compare the effects of flumethrin and ive rmectin treatments of grazing heifers at one farm in central Japan. 64 heif ers were randomly allocated into two groups. Flumethrin (1 mg/kg pour on) w as applied approximately once every 3 weeks to heifers in one group and hei fers in the second group were injected approximately once every month with ivermectin (200 mu g/kg; id). Between groups, no significant differences we re detected in the proportions of animals that showed parasitemia of Theile ria sergenti and conception risks, Significantly lower average log-transfor med nematode-egg counts and higher average daily weight gain were observed in the ivermectin-treated group. Animals with higher body weight at the sta rt of grazing and lower log-transformed total nematode-egg and coccidia-ooc yst counts had higher odds of conceiving. Animals with ivermectin treatment , lower body weight at the start of grazing and lower log-transformed cocci dia-oocyst count had higher daily weight gain. Ivermectin may be more usefu l in this farm because of the higher productivity for cattle and lower cost for its usage. (C) 2000 Elsevier Science B.V, All rights reserved.