Endocrine Response Tests for Fertility Assessment in Awassi Rams in Jordan

The obective of this study was to determine testosterone profiles in fertile and subfertile awassi rams, and todevelop endocrine response tests for investigating subfertility. nine awassi rams were divided equally into threegroups: low (lf), medium (mf) and high (hf) fertility groups. semen quality, testicular and epididymalultrasonic images and testosterone (t) profile were examined for all rams. results indicated that bothultrasonographical images of testicles and semen parameters did not differ significantly among groups. motilityand concentrations of the sperms were lower in the lf (58.8±13.3 % and 0.9±0.5×109/ml, respectively) group.testosterone concentrations were significantly higher in hf (2.7±0.1 ng/ml) group compared to the other groups(0.99±0.2 and 0.7±0.1 ng/ml for lf and mf, respectively). three small doses of gonadotrophin releasinghormone (gnrh) and human chorionic gonadotrophin (hcg) injections resulted in significantly lowertestosterone concentrations in lf (3.2±0.2 and 2.9±0.3 ng/ml, repectively) group than the other ones. inconclusion, t profile and hcg response tests can be used to determine subfertile rams that passed breedingsoundness exam