Material and methods
A total of 810 seven-day-old Japanese quails (Coturnix coturnix japonica) were
sexed according to their cloacal view under sexascope. The chicks were weighed on
a digital balance with 0.1 g precision and their body weights were found between
24.8 g and 26.1 g. The birds were randomly assigned to nine treatment groups, three
replicates of 30 quails (1:2 male to female ratios) in each. Wing marks bearing running
numbers were attached to the wings of all chicks. Treatment groups were fed with
basal diet supplemented with three levels of vitamin E (ROVIMIX® E-50 SD; stable
source of vitamin E in feed, DL-α Tocopheryl acetate) 60, 120 and 240 mg/kg of diet
and vitamin C (ROVIMIX® Stay-C 35; specifically produced for use as a stabilized
source of vitamin C in feed; L ascorbic acid ) 60,120 and 240 mg/kg of diet. Water and
feed were supplied ad libitum.
The birds were kept in a storey cage system in which each sub cage unit (90x48 cm)
contained 30 birds (1:2 male to female ratios). The room temperature was maintained
at 33±2°C during the treatment period (0 to 16 weeks of age). The overhead ruby
infrared heating lamp was used to keep the temperature constant. The groups were
subjected to continuous lighting for 24 h a day for the first two weeks. The lighting
period was gradually reduced to 12 hours a day between weeks 2 and 4. These 12 h
lighting was kept constant between weeks 4 and 8. After week 8 the lighting period
was gradually increased to 17 h. The environmental conditions were the same for all
groups.