Three different antihelmintic drugs were used in the present study (ivermectin, levamisole and
albendazole) on Friesian bulls .The animals were divided into four groups (control untreated
group, ivermectin, levamisole, and albendazole treated groups, respectively). The drugs used at
two doses with 8 weeks intervals between first and second one at 200μg/kg, 7.5mg/kg and
10mg/kg, respectively. Semen samples were collected for 8th weeks after each dose.
Biochemical semen characteristics were estimated. The bulls treated with ivermectin showed
significant increase in semen- ejaculate volume, sperm- cells concentration (x109 / ml), total
sperm output ejaculate (x109 / ml), alkaline phosphatase (ALP) and prostatic acid phosphatase
(ACP) activities in seminal plasma, seminal plasma total proteins, globulin, urea and zinc
concentration; while significantly decreased seminal plasma alanine-aminotransferase (ALT),
aspartate-aminotranferase (AST), and sodium were reported. The bulls treated with levamisole
showed significant increase in semen-ejaculate volume, total sperm output/ejaculate, ALP and
prostatic ACP activities in seminal plasma, seminal plasma total proteins, globulin, urea and
zinc concentrations; while significantly decreased seminal plasma ALT, AST, and sodium were
recorded. In contrary, the bulls treated with albendazole were significantly decreased semenejaculate
volume, sperm motility, seminal plasma total proteins, globulin, creatinine and
calcium. Also, it showed significant increase in seminal plasma enzymes activity (ALT, AST
and ALP) and zinc concentrations. It is interest to note that different anthelmintics treatment
used in this study didn't affect significantly in seminal plasma albumin and total ACP activity.
In conclusion: Ivermectin treatment improved semen qualities by increasing seminal volume and
concentration. Anthelmintics treatment with levamisole should be used carefully under control
during breeding season. Albendazole treatment should be avoided because its harmful effect in
semen by decreasing semen-ejaculate volume, sperm motility, seminal plasma total proteins,
globulin and increasing seminal plasma aminotransferase enzymes activity.