Division of Nutrition and Feed Technology, Central Avian Research Institute, Izatnagar - 243 122 (UP)
2 Corresponding author
1 Part of MVSC thesis submitted to IVRI Deemed University, Izatnagar-243 122 (UP)
A five-week growth bioassay was conducted to investigate the effect of higher dietary concentrations of vitamin E on production performance and primary immune response in broiler quails. For the purpose, 320-day-old heavy body weight quail chicks were randomly selected and divided into 20 groups of 16 chicks each. They were reared in electrically heated battery cages fitted with feeders and waterers. A basal diet composed of ground yellow maize, soybean meal, fish meal, rice bran etc. and having 24% crude protein and 2700 kcal ME/kg was formulated. From this basal diet, five experimental diets were prepared by incorporating vitamin E (as α-tocopherol acetate) at graded levels of 75, 150, 225 and 300 mg/kg in diet. Each experimental diet was offered ad libitum as mash form to four groups of quail chicks for Five weeks. Production performance in terms of body weight gain, feed intake, feed conversion ratio and mortality were recorded. For immunological studies, on 28th day of experimental feeding, two birds from each replicated group were intravenously injected with 0.2 ml of 2.5% SRBC suspension. The blood samples were collected at 0 and 6th day post inoculation for HA antibody titre estimation. During 4th week of experimental feeding, two birds/replicate/treatment were also injected with PHA-P (1 mg/ml PBS) intradermally to monitor the in vivo cell mediated immune response by measuring the footpad index. At the end of experiment, two birds/replicate/treatment were again picked up randomly and sacrificed to measure the lymphoid organ weights.
The mean gains in body weight during 0–5 weeks of age of growing quails were found to be statistically similar in all the treatment groups. Similarly, Group wise feed consumption and feed conversion ratio also remained same among various dietary groups. Moderate dietary vitamin E levels (75 and 150 mg/kg) showed an appreciable increase in humoral and cell mediated immune response in quails. Relative weights of thymus and liver, in general, increased with dietary vitamin E level. Spleen weight, however, showed inverse trend. It was inferred that growth performance of growing quails remained unaltered by additional supplementation of vitamin E in diet. However, moderate dietary vitamin E levels (75 and 150 mg/kg) tended to improve indices of immune response.
Quails, dietary vitamin E, growth performance, immune response
