Three hundred and ninety eight Californian (CAL) rabbits were used in the present study to determine the effects of dietary supplementation with 100 mg Toyocerin® /kg feed on some productive and reproductive performance of growing and mature rabbits.
The present study included two experiments; the first experiment was lasted for 40 days and was carried out during growing period (from weaning to marketing age at 70 days) by using 250 weaned Californian rabbits aged 30 days. The second experiment was lasted for 4 months and was carried out on 128 multiparous does and 20 sexual mature bucks of CAL rabbits aged nine months. The animals of each experiment were divided into two experimental groups. The first group was used as a control and fed a commercial diet without supplementation. The second group was fed a control diet supplemented with 100 mg Toyocerin® probiotic per kg of feed.
The results obtained revealed that, daily body weight gain; feed efficiency and final body weight values of growing CAL rabbits were significantly (P≤0.05) higher with Toyocerin® fed rabbits compared to the control one. Supplementation with Toyocerin® increased significantly (P≤0.05) spleen and thymus indexes and cell mediated immunity. Rabbits received Toyocerin® recorded the highest (P≤0.01) values of caecal bacteria count (total microbial count, lactobacilli and celluloytic bacteria), except for ureolytic bacteria. Blood picture of growing CAL rabbits including red and white blood cells count; hemoglobin concentration and hematocrite percentage and some blood serum constituents including total protein and its fractions (albumin and globulin) were within the normal physiological range, however it recorded the higher values for treatment group. Liver activity of growing CAL rabbits represented by values of each of aspartate aminotransferase (AST), and alanine aminotransferase (ALT) also increased significantly (P≤0.05) by Toyocerin® supplemented diet.
Adding Toyocerin® to the diet of CAL buck rabbits significantly (P≤0.05) improved their reproductive traits represented by libido and physical semen quality (semen-ejaculate volume; advanced-sperm motility; live and normal spermatozoa; acrosome status and sperm-cell concentration per ml and per ejaculate);. No significant for Toyocerin® inclusion on scrotal circumference, testicular index and testosterone concentration. Mating activity of CAL buck rabbits received Toyocerin® were significantly (P≤0.05) higher than those fed the control diet. Kindling rate, litter size and weight at birth; milk yield and pre-weaning mortality rate were significantly better (P≤0.05) for those fed Toyocerin® diet than those fed the control diet.
Conclusively, it can be concluded that dietary supplementation with Toyocerin® probiotic at level of 100 mg per kg of feed improve growth and reproductive performance of Californian rabbits.