Glycerides of lauric acid supplementation in the chicken diet enhances the humoral and cellular immune response to infectious bronchitis virus

Abstract

Controlling pathogenic infections while reducing antibiotic usage is an important challenge during poultry production. In addition to vaccination strategies, several solutions to enhance the immune response against pathogens are evaluated. In this study, we aim to determine the effects of the glycerides of lauric acid (GLA) supplementation in chickens’ diets on humoral and cellular immune response pathogenic infections, using an in vivo model of infectious bronchitis virus (IBV). One-day-old Ross 308 broilers were vaccinated with live attenuated IBV and fed diets supplemented with or without GLA at 3 kg/ton. The levels of early (day 7) specific anti-IBV in sera were significantly increased in broilers fed GLA, compared to the control groups (P<0.05), showing a stronger primary humoral response. The secretion levels of main cytokines remained similar in spleens of all the experimental groups. However, the splenocytes from broilers fed GLA showed higher activation and effector abilities when measured by IFN-γ ELISpot in presence of N-261–280 IBV peptide or Concanavalin A (Con A), a pan T lymphocytes mitogen. In response to N-261–280 peptide, GLA group showed a 2-fold increase of spot numbers (P < 0.05) and 3-fold increase of spot surfaces (P < 0.01) compared to the control groups. Similarly, Con A stimulation showed a 2-fold increases in spot surfaces and numbers in the GLA supplemented group compared to the control group (P < 0.01). In summary, GLA supplementation in chicken feed enhances the primary humoral immune response and strengthen the T lymphocytes mediated cellular immune response. These findings demonstrate how GLA can improve chicken resilience against pathogenic challenges by enhancing their immune responses.