| ABSTRACT The influence of fasting and vaccination against infectious bronchitis (IB) on growth, gastrointestinal development, and morphometric parameters of the small intestine of newborn broiler breeders was investigated. Weight gain (WG), feed conversion ratio (FCR), gastrointestinal visceral growth, residual yolk sac, and morphometric parameters of the small intestine were measured in chicks aged up to 21 d. We showed that WG was lowest in chicks exposed to longer fasting periods (72 h), although compensatory gains with increasing age were also observed. Unvaccinated chicks performed better at seven days; however, at 21 d of age, a compensatory response led to better FCR in vaccinated birds. Allometric growth of the gastrointestinal tract was affected... |
