EFFECT OF DIETARY SUPPLEMENTATION OF ORGANIC SELENIUM AT DIFFERENT LEVELS ON REPRODUCTIVE PERFORMANCE OF RABBIT DOES
ABSTRACT
The effect of dietary supplementation of organic selenium at different levels on reproductive performance of rabbit does was investigated using 16 (12 does and 4 bucks) rabbits. The rabbits were of New Zealand white, Dutch and chinchilla breeds. The twelve rabbit does were randomly assigned to four experimental treatment groups (T0, T1, T2 and T3) according to the amount of organic selenium supplementation in a completely randomized design (CRD). Rabbits in T0 served as the control and received 0.00mg/kg Se supplement diet daily, while those in T1, T2 and T3 were given 0.15, 0.30 and 0.45 mg/kg organic selenium yeast, respectively. Each rabbit in a treatment was housed in individual cage and served as replicate. Rabbits in each treatment were mated using four bucks (one buck per treatment). The parameters measured were: birth weight of the litters, body weight of the dam after kindling, litter sizes at birth including stillbirths, conception rate, gestation length, body weight of does during gestation, litter weight at weaning, litter sizes at weaning and growth rates of kits. . Haematological parameters and oxidative enzymes were also determined. Results showed that selenium supplementation in the diets had no significant (p > 0.05) effect on gestation length, litter size at birth, number of stillbirth, doe body weights at kindling and litter body weights at birth. However, selenium supplementation had significant effect (p < 0.05) on litter size at weaning, litter body weight at weaning and pre – weaning weight gain of kits during lactation. Doe weight gain during gestation and growth rate of kits were not significantly (p > 0.05) different among the treatment groups. Weight gain of kits at weaning was higher in treatment one with only two kits as the average kits weaned. Litter size at weaning was significantly higher at treatment 3 (6.50) and for treatment 2 (5.00). The higher values in number of kits at birth, birth weight of kits and litter size weaned as recorded in treatment 2 showed the significant role of selenium as an anti-stress in the diets of the animal. Inclusion levels of selenium had no significant (p > 0.05) effect on such haematological indices on RBC of rabbits. However, there were significant differences (p < 0.05) among treatment group on haematological values of Hb, PVC, Neutrophils and eosinophils. There was a significant difference (p < 0.0.5) among treatment groups on follicule stimulating hormone (FSH) secretion, however no difference was found in LH. Selenium in the diets of rabbit does had no significant effect (p > 0.05) on such oxidative enzymes like catalase, , selenium and reduced glutathione. However, there were significant differences (p < 0.05) among the treatment groups on oxidative enzymes of MDA, SOD and glutathione peroxidase, glutathione, and glutathione transferase with higher significant (p < 0.05) effect on SOD. It was therefore concluded that under good nutritional and other management practices, inclusion of selenium in diets of rabbit does at 0.30mg/kg feed will increase the number of kits per doe per year even though best results for weight gain of litters at weaning were obtained with 0.15mg/kg selenium supplementation in the diet and this will enhance maximum productive performance, thus maximum/higher economic returns from the enterprise.