Co-Authors:
Bartov, I., Department of Poultry Science, Agricultural Research Organization, Center, P.O.B. 6, 50250, Bet Dagan, Israel
Abstract:
1. Two factorial experiments were carried out with male broiler chicks from 6 to 28 (experiment 1) and from 7 to 49 (experiment 2) d of age to evaluate the combined effect of virginiamycin (VIR), dietary energy concentration, and energy-to-protein (E:P) ratio on performance and the utilisation of dietary nutrients. 2. VIR had no significant effect in either experiment on food intake or weight gain, but significantly improved food efficiency up to 28 d of age (P<0.001 and P<0.05 in experiments 1 and 2, respectively). 3. VIR consistently and significantly (P<0.01) decreased fat excretion, improved fat relative retention and increased dietary AMEn. VIR also significantly (P<0.01) increased relative retention of dry matter, while it did not affect nitrogen balance. 4. Neither of the variables of performance and utilisation of dietary nutrients was affected by the interactions between VIR and either dietary E:pratio or energy concentration. It is concluded, therefore, that the effect of VIR in increasing the utilisation of dietary energy does not depend on the above factors. © 1992, Taylor & Francis Group, LLC. All rights reserved.