Reproductive performance, blood testosterone, lipid peroxidation and seminal plasma biochemistry of rabbits as affected by feeding Acacia saligna under subtropical conditions

Thirty-two New Zealand White growing rabbits (eight-week old) were used to determine the effect of feeding acacia-based diets on semen characteristics, plasma testosterone, free radicals, seminal plasma enzymes and lipids. Rabbits were randomly assigned to four equal groups. The first group (control) was fed a basal diet only, and the other three groups were fed other three diets, as follows: 80% of basal diet + 20% of acacia leaves (low), 60% of basal diet + 40% of acacia leaves (medium) and 40% of basal diet + 60% of acacia leaves (high), respectively for 32 week. Semen samples were collected throughout the last 12 week of the experimental period. Rabbits fed on different levels of Acacia showed no significant changes in libido (reaction time), ejaculate volume, sperm concentration, packed sperm volume and initial hydrogen ion concentration compared to control. However, low and/or medium levels of Acacia caused significant (P < 0.05) increase in total sperm output (TSO), sperm motility (%), total motile sperm per ejaculate (TMS), normal sperm, total functional sperm fraction (TFSF), semen initial fructose, live sperm and plasma testosterone. On the other hand, high level of Acacia did not show any significant change in TSO, sperm motility (%), TMS, initial fructose, TFSF or testosterone, while live and normal sperm decreased. All levels of Acacia caused a significant decrease in the concentrations of thiobarbituric acid-reactive substances (TBARS) and an increase in the activity of glutathione S-transferease. The activities of lactate dehydrogenase (LDH), aminotransferases and phosphatases were significantly increased in seminal plasma of animals fed low or medium levels of Acacia. Seminal plasma total lipid, triglyceride, low density lipoprotein and free fatty acids were significantly (P < 0.05) decreased in low or medium levels of Acacia. On the other hand, total cholesterol, percentage cholesterol (out of total lipids) and high density lipoprotein were significantly (P < 0.05) increased in seminal plasma of rabbits fed on low or medium levels of Acacia. High level of Acacia did not cause any changes in the previous parameters. It can be concluded that up to 40% Acacia leaves could be used successfully and safely in the diet of rabbits without adversely affecting their reproductive performance under subtropical conditions.