Lack of effect of dietary energy‐to‐protein ratio and energy concentration on the response of broiler chickens to virginiamycin

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 less than 0.001 and P less than 0.05 in experiments 1 and 2, respectively). 3. VIR consistently and significantly (P less than 0.01) decreased fat excretion, improved fat relative retention and increased dietary AMEn. VIR also significantly (P less than 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:P ratio 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.

Virginiamycin and Caloric Density Effects on Live Performance, Blood Serum Metabolite Concentration, and Carcass Composition of Broilers Reared in Thermoneutral and Cycling Ambient Temperatures

“…Henry et al (1986) reported that VM had no influence on 21-d BW and feed efficiency. However, results of the current study and other published reports (March et al, 1978;Proudfoot et al, 1990;Bartov, 1992) are in agreement that VM supplementation linearly enhanced 21-d BW and feed efficiency without influencing feed consumption. Mode of action for the VM growth improvement at 21 d of age has been suggested by previously published studies to be related to improved dietary fat retention and a resulting elevation in dietary AME n content (March et al, 1978;Bartov, 1992).…”

“…However, results of the current study and other published reports (March et al, 1978;Proudfoot et al, 1990;Bartov, 1992) are in agreement that VM supplementation linearly enhanced 21-d BW and feed efficiency without influencing feed consumption. Mode of action for the VM growth improvement at 21 d of age has been suggested by previously published studies to be related to improved dietary fat retention and a resulting elevation in dietary AME n content (March et al, 1978;Bartov, 1992). It was also suggested that reduction of Clostridia perfringens population in the ileum of chicks with VM supplementation is correlated with weight gain and feed efficiency (Stutz and Lawton, 1984).…”

“…The positive 15 ppm VM weight gain response during CT, observed in the current study, is in agreement with previous findings (Belay and Teeter, 1994). In the current study, the main effect of VM was not significant for SURV, 49-d BW, G and G:F. In contrast, Marrett (1989) reported that the beneficial response to antibiotics However, the data reported herein and previous reported studies suggest that the effect of a growth promotant on live performance of broiler may be more pronounced at younger ages (Eyssen and De Somer, 1963;Marusich et al, 1973;March et al, 1978;Bartov, 1992). Broilers fed the high CD diet had elevated (P < 0.05) 49-d BW and G associated with 5.8% higher (P < 0.05) FC than those fed the low CD diet.…”

“…Virginiamycin efficacy also has been reported to be more pronounced in turkeys (March et al, 1978) and broilers (Buresh et al, 1984) fed low caloric density diets. The increased AME n in broilers with VM supplementation has been attributed to improved dietary fat retention (Bartov, 1992). The influence of VM on net energy efficiency is yet unknown, however, 15 ppm VM supplementation in diets fed to broilers exposed to high environmental temperature was reported to increase weight gain whereas the 20 ppm VM fortification was reported to reduce mortality and increase saleable carcass (Belay and Teeter, 1994).…”

Zum Einfluss unterschiedlicher Behandlungsverfahren und Zusatzstoffe auf ernährungsphysiologische Parameter und Leistung wachsender Broiler nach Verabreichung weizenbetonter Futtermischungen

“…Durch antimikrobielle Wachstumsförderer sind die Futternährstoffe für Broiler besser verfügbar und werden effizienter umgesetzt (MARCH et al, 1978;HARNISCH et al, 1981;BARTOV, 1992) , 1997). Der Autor stellte in der gleichen Arbeit bezüglich der N-Umsetzung (N-Bilanz und PEW) keine einheitlichen Effekte von Zink-Bacitracin fest.…”