Feed restriction is a common tool utilized in broiler breeder production. The period of most severe feed restriction is during the rearing phase. In order to feed at the proper requirements the maintenance requirements of the birds must be estimated. Biometric models have been previously developed, however these estimates may loose accuracy due to changes in genetic selection criteria. In order to verify the estimates of metabolizable energy of maintenance (MEm), a study was conducted from 0-20 weeks with a total of 8,500 Ross 308 females placed at two separate commercial farms. The study also examined the effect of temperature on maintenance requirements of commercial broiler breeders. Although the effect of temperature was inconclusive, the estimates of maintenance requirements were consistent with other experimental findings in the literature.
Feed restriction and genetic selection on the expression and activity of metabolism regulatory enzymes in rabbits
