The Effects of Savory (Satureja khuzistanica) Extract on Performance, Organ Weight, Blood Parameters and Immune Function in Heat Stressed Broilers

Abstract

An experiment was conducted to study the effect of savory (Satureja khuzistanica) extract on the performance, organ weight, immune response and hepatic enzymes in broiler chickens. 320 day-old Ross chickens were assigned to four distinct treatments in a completely randomized design. Each treatment was administered to four replicates of twenty birds. The variables were heat stress (34 ± 2 ˚C for 8 hours) and savory extract (0.4 ml/L) in drinking water. Feed intake (FI), weight gain (WG) and feed conversion ratio (FCR) were measured in successive weeks of the trial. The relative weights of different organs (dressing, breast, thigh, liver, heart, spleen and bursa of Fabricius) determined at 42 days. The serum glucose and blood plasma content of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were measured by blood sampling at 42 days. Plasma IgG were quantified on days 21, 28, 35 and 42. The savory extract did not affect FCR, or the relative weights of different organs (P>0.05). BW and FI increased with savory oil inclusion (P<0.05). Further, the savory extract reduced plasma glucose, AST and ALT in heat stressed broilers significantly (P<0.05). ALP content also declined, but not significantly (P>0.05). Blood IgG in heat stressed broilers, increased in every case of treatment with savory extract (P<0.05). In conclusion, in conditions of heat stress, 0.4 ml/L of savory extract improves economic proficiency in broiler flocks due to the accumulation of minute advantages in increased WG, FI, improved IG and reduced hepatic enzymes.