Comparative effects of virginiamycin, betaine, and electrolyte on compensatory gain and the general performance of male broilers, exposed to high ambient temperature stress

Scope and method of study. The purpose of this study was to examine virginiamycin (VM), betaine (BE) and electrolyte (EL) effects on compensatory gain (CG) and performance of male broilers exposed to cycling-high ambient temperatures heat stress (HS). Variables monitored included production, carcass composition, survivability (SR), serum chemistry and body temperature (BT). Two hundred eighty birds, exposed to HS from day 18 to 33, were moved to a thermoneutral (TN) environment and contrasted with two hundred eighty birds were reared at TN (24 C). Both flocks were compared at the age of 49 d for CG and performance. Proc GLM was used to compare mean differences between treatments.;Finding and conclusions. The CG of high ambient temperature exposed birds exceeded the TN controls by 39% (p = 0.0001). Further, supplementation with BE elevated (p < 0.01) CG by 47% over TN controls. Body weight (BW) and weight gain (WG) 40 days of age was increased (p < 0.05) for VM birds when compared to TN. Survivability, dry matter, and body fat were all increased (p < 0.03) in CG birds compared to TN. Further, Betaine supplementation increased (p < 0.02) breast weight, DM and bone mass concentrations (BMC) of CG birds. Electrolyte increased (p < 0.01) the average CG of day 40 and 48 age classes while decreasing (p < 0.007) body temperature (36d) of CG birds when compared with TN birds. Plasma chloride, magnesium, sodium, albumin, DM, BMC, and lean mass were increased (p < 0.05) in CG birds supplemented for VM compared to TN. In conclusion it is the finding of this study that broilers with previous exposure to HS have the potential for accelerated growth once the stress is alleviated. Further, the data indicate that supplementation with BE, EL and VM improves body weight and gain composition either during and/or following high ambient temperature exposure.