en Original Article Original Article <div dir="ltr"></div> <strong>Background</strong>: To ascertain the effects of tropical leaf meals on semen production and semen quality.<br> <strong>Objective:</strong> This study was conducted with the main objective of investigating the effect of neem leaf meal on physiological responses of rabbit bucks fed graded levels of neem leaf (<em>Azadirachta indica A. Juss</em>) meal.<br> <strong>Materials and Methods</strong>: The varying levels of neem leaf meal (NLM) in the different experimental diets were 0, 5, 10 and 15% respectively. Four groups of nine crossbred New Zealand type rabbit bucks each, aged 7-8 months were randomly assigned to four diets containing neem leaf meal (NLM) at 0% (control) (CD₀), 5% (CD₁), 10% (CD₂) and 15% (CD₃) respectively for 16 weeks.<br> <strong>Results: </strong>The sperm concentration values obtained were 20.15 &times;10⁶/ml, 18.04&times;10⁶/ml, 13.65&times;10⁶/ml, 6.46 &times;10⁶/ml for the CD_0,CD₁, CD₂ and CD₃ groups respectively. The results obtained indicate that sperm motility were lowest (p<0.05) in the treatment groups than the control group. Total sperm per ejaculate was similar (p>0.05) between the control and those on 5&ndash;10 %NLM dietary groups however, the value for the 15%NLM group was significantly (p<0.05) lower than that of the control. Abnormal sperm percentage of the bucks fed 15% NLM was significantly (p<0.05) higher than those bucks on CD₁, CD₂ and CD₃ groups. The seminiferous tubule diameters were significantly smaller in the 15% NLM (203&micro;m) than the other 3 dietary groups. All the other variables measured including semen volume, weight of testis and reaction time did not differ (p>0.05) among the experimental group.<br> <strong>Conclusion:</strong> The results of the study indicate that the inclusion of neem leaf meal up to 15% in the ration of matured rabbit bucks could cause mild depressive effect on the spermatogenesis, semen quality and seminiferous tubule diameter. Rabbits, Neem, leaf, Histology, Semen. 23 0 http://ijrm.ir/browse.php?a_code=A-10-549-206&slc_lang=en&sid=1 Ifeanyi Princewill Ogbuewu Yes Department of Animal Science and Technology, Animal Physiology Laboratory, Federal University of Technology, Owerri, P.M.B.1526, Owerri, Nigeria Ifeanyi Charles Okoli No Department of Animal Science and Technology, Animal Physiology Laboratory, Federal University of Technology, Owerri, P.M.B.1526, Owerri, Nigeria Michael Uwaezuoke Iloeje No Department of Animal Science and Technology, Animal Physiology Laboratory, Federal University of Technology, Owerri, P.M.B.1526, Owerri, Nigeria