Abstract

The objective of the current study was to evaluate the efficacy of abamectin in calves naturally infested with GIT parasites. 215 local breed calves were used in this study seven months to one year old males, and 80-150 kg weight. Result indicated that infestation rate were 42.8%, where as fecal examination & larval culture revealed the presence of 8 species of round worms. The highest rate of infestation showed to be by the larvae of Haemonchus species followed by Trichostrongylus, Strongyloides and Ostertagia respectively. Other species were observed less frequently. Among clinical sings, rough coat & loss of body condition were the most obvious symptoms in most of infected calves examined. The percentage of mixed infestation was 66.6% while the single infestation was 33.4%, the domination of light infestation was noted. The efficacy of abamectin against gastrointestinal parasites was 100% depending on the egg counts reduction, this efficacy persisted for 20 days after treatments and then decline to about 97.98% at the end of this study. The blood picture was affected after treatment with abamectin which causes an improvement in the number of RBCs, Hb concentration values, packed cells volume and percentage of neutrophils and reduction in the percentage of eosinophils.