Effect of Green Tea on Weight Gain and Semen Quality of Rabbit Males

SIMPLE SUMMARY: The consumption of green tea can reduce the occurrence of inflammatory and cardiovascular diseases, diabetes, cancer and obesity in humans. Due to its antioxidant and anti-microbial effects, green tea is considered an additive to feed in animal production to substitute for antibiotics. The goal of this study was to evaluate the action of the green tea plant (Camellia sinensis, L) given in powder form on male rabbits’ reproductive functions (sperm concentration and motility, testicular morphology) and some non-reproductive traits (weight gain, blood metabolic/haematological and biochemical parameters). The obtained results demonstrate a reduction in rabbit weight gain, but deterioration of sperm quality under the influence of green tea feeding. This study suggests that green tea can affect the metabolic and reproductive systems of rabbit males in different manners, which should be taken into account when assessing the impact of green tea on a living organism. ABSTRACT: The goal of the current study was to evaluate the action of the green tea plant (Camellia sinensis, L) on male rabbit reproduction and some non-reproductive indexes. Male rabbits were fed either a standard diet (control group) or a diet enriched with green tea powder (experimental groups; E): 5 g (E1) or 20 g (E2) per 100 kg of the milled complete feed mixture. Weight gain, sperm concentration, total and progressive motility, as well as haematological, and biochemical parameters and changes in testicular tissue histomorphology were evaluated. Feeding with green tea, at both tested concentrations, decreased weight gain per week and the total average weight gain compared to the control group (p < 0.05). Furthermore, green tea decreased sperm concentration, motility and progressive motility in the group fed with a lower dose (5 g) of green tea powder (p < 0.05), whilst a higher dose (20 g) was neutral. Some haematological and biochemical indexes, like medium-size cell count (MID), mean corpuscular haemoglobin concentration (MCHC), platelet percentage (PCT), levels of phosphorus (P) and total proteins (TP) were decreased in one or both experimental groups (p < 0.05), whilst the triglyceride level (TG) was increased in the E2 group (p < 0.05). The thicknesses of the testicular seminiferous tubules and epithelial layer were not affected by any concentration of green tea powder (p > 0.05). These observations suggest that green tea in the diet may have an adverse effect on rabbit growth and sperm quality, but their effect may be potentially dose-dependent.