Abstract

Objective: The trial was aimed at assessing the effect of phytogenic feed additive (PFA), a natural adaptogen, on growth performance, serum neopterin level, and cutaneous basophil hypersensi¬tivity (CBH) response in heat-induced stress model of broilers.
Materials and Methods: One-day-old Ross 308 chicks (N = 360) were randomly distributed among normal control (NOR), heat-stress control (HSC), and PFA treatment (HSC plus PFA at 200 gm/ton of feed) group. HSC and PFA groups were subjected to heat stress (HS) (32°C–36°C) from 9:00 a.m. to 5:00 p.m. for 35 days. The impact of HS on growth performance, serum neopterin level, and CBH response was assessed.
Results: High ambient temperature worsened the performance traits [bodyweight (p < 0.05) and feed conversion ratio] and significantly lowered the serum neopterin level and CBH response in the HSC group when compared to the NOR group. However, supplementation of PFA at 200 gm/ ton of feed to birds mitigated the detrimental effects of HS.
Conclusion: PFA at 200 gm/ton demonstrated the immunomodulatory effect through the resto¬ration of serum neopterin level, CBH response, and growth performance traits in heat-stressed broiler chickens. Thus, PFA can be used as a natural adaptogen to increase the stress resistance and mitigate the negative consequences of various stressors in broiler chickens.

Key words: Broiler; heat stress; neopterin; cutaneous basophil hypersensitivity; phytohemagglutinin-P; cell-mediated immune response