Sixty cattle from Canchim breed with 15 months were mantained in a Bracharia decumbens Stapf pasture were randomly alloted into three balanced treatments designed to the control of gastro-intestinal nematodes (T1: control group; T2: 1ml/50kg BW of Doramectin, corresponding to 200mug/kg; and T3: Levamizole 1ml/40kg BW, equivalent to 3,75 mg of the active principle per kg of body weight). The administration was proceeded through the parenteral via, subcutaneously and the verminotic infeccion took place naturally. The experiment was carried out at the Canchim Farm, head office of the Animal Prodution Research Center of Embrapa (CPPSE) located in São Carlos, São Paulo State, Brazil, from April/95 to June/95. It has been determined body weight, eggs per gram (EPG) and mean corpuscular volume (MCV), over six periods (P) as follows: 0, 14, 28, 42, 56 and 70 days after drug administration. The mathematical model for statistical analysis included effects of treatment (T) and period, as well T x P interaction. From day 14 on, Doramectin presented the least EPG (P<0.01) compared to other treatments, which showed no difference (P>0.05) between each other from day 42 on. Treated animals showed similar weight gains (P>0.05) up to day 42. Control group animals had a reduction in the weight gain (P<0.05), which was negative (loss of weight) at 42 and 70 days. In concern to MCV, treated animals were similar (P>0.05) over the experimental period. In the other hand, control group showed lower calves (P<0.05) since day 28.
beef cattle; dry season; control of endoparasites; Doramectin; Levamizole
