Reproductive toxicity of neem seeds (Azadirachta indica) in male quail (Coturnix coturnix japonica)

Abstract

Considering that neem (Azadirachta indica A. Juss.) causes deleterious effects on fertility, the objective was to evaluate the effect of feeding quail (Coturnix coturnix japonica Linnaeus, 1758) of 90 days old with neem seeds on seminal quality, biometric parameters, and testicular morphometrics, as an experimental model. After the 30 day adaptation period to the experimental conditions, birds were randomly distributed in five treatments of neem seeds incorporated into feed, with 10 replicates: T1 (0%), T2 (5%), T3 (10%), T4 (20%) and T5 (40%). After 60 days of receiving experimental rations, their semen was collected to evaluate the sperm quality, the birds were euthanized, and testes were submitted to biometric, histological, and histomorphometric evaluation. The data were evaluated by analysis of variance and later by Tukey test with a significance level of 5%. The mean values of testicle weight, length, and width significantly decreased in T4 and T5, due degeneration of germinal epithelial cells. In these treatments, it occurred a significant increase (P>0.05) in the average values of the tunica albuginea thickness and a significant reduction in the values of the seminiferous tubule diameter and the height of the germinal epithelium. In addition, the mean values of seminal volume, sperm concentration, sperm motility, vigor, and sperm viability were significantly reduced. Thus, the use of neem in bird feeding, as well as the use for therapeutic purposes, is questionable, considering its negative impact on reproduction.