The effect of ventilation on performance body and surface temperature of young turkeys.

Efficient ventilation affects thermoregulation and, thereby, the performance of domestic fowl. This became crucial as genetic selection for growth development significantly coupled with increased metabolic rate. The specific aims of this study were to elucidate a) the effects of different rates of ventilation on young turkey performance during exposure to constant 35, 30, and 25 degrees C and b) their effects on body temperature and surface temperature. In 3 separate experiments, turkeys were raised under regular conditions up to 3 wk of age. Thereafter, they were acclimated for 1 wk to the targeted ambient temperatures (T(a)) and to air velocities of 0.8, 1.5, 2.0, or 2.5 m/s and raised under those conditions up to 6 wk of age. Turkeys exposed to 35 degrees C performed optimally at an air velocity (AV) of 2 m/s; they exhibited significantly higher feed intake and significantly lower body temperature. At 30 degrees C, performance was optimal at AV of 1.5 to 2.5 m/s and significantly lower at 0.8 m/s. Performance of turkeys exposed to 25 degrees C did not vary with AV. Comparison of BW and feed intakes of turkeys exposed to the 3T(a) levels revealed significantly higher feed intake at 25 degrees C but similar BW compared with those exposed to 30 degrees C, meaning that those exposed to 25 degrees C used more energy for maintenance than for growth. In general, surface temperature of the body declined significantly with T(a), whereas that of the face and legs was significantly lower at 25 degrees C. It can be concluded that AV affects the performance of young turkeys. The range of AV within which BW was optimal expanded as T(a) declined. It can be further concluded that the combination of 30 degrees C with AV from 1.5 to 2.5 m/s was optimal for young turkeys.