Resultant Effect of Early Endogenous Thermal Acclimatization on Performance of Heat-Stressed Broiler Finishers on Different Levels of Dietary Protein

Abstract

The guarantee of a naturally stable thermal environment that will keep poultry birds within the zone of maximum comfort all year round in tropical and sub-tropical regions in the 21 st century cannot be established. Therefore, it becomes necessary to look into stabilizing internal environment of vulnerable chicks, with the sole aim of re-exhibiting their masked potentials for fast growth and high yield. Crude protein (CP), though essential for growth and repair, dissipates more heat load than other nutrients during metabolism. Hence, it becomes imperative to investigate the effect of early endogenous thermal acclimatization on performance of heat-stressed broilers (HSB) at finisher phase. Using a total of 288, one day-old Arbor Acre broiler chicks, birds were randomly allotted to four dietary treatments (T1 -21 % CP; T2 -19 % CP; T3 -17 % CP; and T4 -15 % CP) at finisher phase with six replicate groups in a completely randomized design in order to evaluate the resultant effect of a 2 %, 4 % and 6 % reduction in dietary CP. Data were analysed using descriptive, ANOVA, regression and correlation statistics. Low crude protein diets improved performance of HSB at finisher phase. However, a 2 % dietary CP reduction (19 % CP) best enhanced performance of HSB at finisher phase. Some parameters that were supposed to strongly correlate were not as a result of the influence of early endogenous manipulation. Endogenous heat load reduction through dietary crude protein and electrolyte inter-play have resulted in a proportionate increase in feed intake, body weight gain, protein efficiency ratio and enhanced feed conversion ratio in HSB at finisher phase. The resultant effect of early endogenous thermal acclimatization on performance of heat-stressed broiler chickens at finisher phase has been beneficial.