Effect of antihlmenthic drugs on reproduction in cows

The present study was conducted on a total of 155 cows infestedwith gastrointestinal nematodes and located in Dakahlia provine. Theseanimals were devided into three groups, during the postpartum period (75cows); in case of anoestrus (40 cows) and repeat breeder due toendometritis (40 cows). Each group was assigned into four subgroups;_ levamisole, ivennectin, pyrantel tartrate treated subgroups, in addition to control group for studying the effect of anthelmintic drugs on thereproduction in cows. In case of repeat breeder in addition to theanthelmintic drug a dose of 50 ml oxytetracycline hydrochloride 5% wasinfused intrauterine at day of treatment by anthelmintic drugs.Both treated and non-treated subgroup were examined rectally everyweek to check the differnt reproduction performances for the differentgroups.Blood samples were collected immediately before and every weekafter treatment till time of heat for the chemical analysis.,from the statistical analysis of the obtained results, it has beenfound that:1- The clinical uterine involution, interval from calving to the onset of the first observed heat and the open days period from calving to conceptionwere significantly (P < 0.01) shorter in diffeent treatment groups thanthat in the control group during the postpartum period.2 - In case of anoestrus, there was a highly significant (P < 0.01) decreasein the interval elapsed from the st311 of treatment to the onset of heat for