Broilers. Forty broilers of Ross 308 breed,
aged 1-day, with an average initial body weight of 42 g,
obtained from a commercial hatchery, were randomly
divided into four equal groups (five male and five
female chicken): group I (control) - non-modified corn
and soybean meal, group II - non-modified corn and GM
soybean meal, group III - GM corn and non- modified
soybean meal, and group IV - GM corn and GM
soybean meal. The chickens were kept from 1 to 42 d of
age in pens set on a concrete floor covered with wood
shavings, in an environmentally-controlled room containing individual pen lamps and a ventilation
system. The pen dimensions were 1.60 x 2.00 m,
equaling 3.20 m2 total floor space and 0.08 m2 per bird.
A continuous 24-h lighting programme was used.
During the experiment, feed and water were provided ad
libitum. The environmental conditions were similar for
all treatments (pens).