Expression profiling of immune genes associated with black pepper ( Piper nigrum ) powder supplementation in the diets of broiler chickens.

The present study was conducted on three hundred commercial broiler chicks with the aim to evaluate the effect of black pepper supplementation on expression of TLR gene where the negative control (T1) group was given basal diet without antibiotic and in the control group (T2) basal diet with antibiotic was fed, third (T3), fourth (T4), fifth (T5) and sixth (T6) groups were supplemented with black pepper powder (BPP) at levels 0.25, 0.5, 0.75 and 1%, respectively in diet. After 42 days, a significant reduction ( p <  0.05) in ileal E. coli count and a higher value of Lactobacilli was recorded in the various black pepper powder supplemented groups, and they differed significantly ( p <  0.05) from negative control. The mRNA expression levels of Toll-like receptors (TLR 2 and TLR 4) had shown significant ( p <  0.05) changes in experimental groups. The TLR 2 and TLR 4 genes revealed differential expression in all black pepper supplemented groups in comparison to negative control and control group, while TLR 7 did not show any significant change. Thus, supplementation of black pepper powder can be exploited as an immunomodulator to enhance adaptive immune response of broiler chicks after validation on large number of samples.