Effect of Anise and Mint extracts (volatile oils) supplementation in the diet of weanling New Zealand White rabbits in hot climate

A total of 75 weanling New Zealand White rabbits aged 5 weeks were divided into 5 groups nearly equal in the average of body weight to study the effect of feeding commercial pelleted diet supplemented with two levels (1 or 2 cm(3)/kg diet) of Anise or Mint extracts (volatile oils) as a mean to improve the feed utilization and digestion in the hot summer. The rabbits raised on this rations up to 14 weeks of age (the suitable marketing age in the summer of Egypt). The rabbits which fed diet with Mint extract 1 cm(3)/kg diet) showed significant difference (P<0.01) for weight gain from 13 to 14 weeks of age. A significant effect (P<0.05) was also detected for the digestibility coefficient of crude protein, TDN, N-retained, serum total protein creatinine, total lipids and cholesterol for the same group when compared with control and control plus Anise extract (2 cm(3)/kg diet) groups. Also, volatile oils inclusion surpassed significantly (P<0.01) control group in feed consumption and conversion from 5-14 weeks of age. Type of diet did not affect neither the digestibility coefficients of DM, OM, EE, CF and NFE nor any of the carcass traits studied. N-intake and faecal-hl for control group were significantly (P<0.05 and P<0.01, respectively) higher than the other groups. The obtained weight gain in rabbits fed basal diet supplemented with Mint extract (1 cm(3)/kg diet) could realize the highest economical efficiency at 14 weeks of age.