L-arginine regulates immune functions in chickens immunized with intermediate strain of infectious bursal disease vaccine

Abstract

The present studyinvestigated the effects of dietaryarginine (Arg) supplementation on immune functions of broiler chickens inoculated with infectious bursal disease vaccine (IBDV). A total of 500 one-day-old female Ross (308) broilers were randomlyassigned into 10 treatments (5 replicates per treatment, 10 birds per replicate). On day 14, birds were inoculated intramuscularlywith IBDV or saline. Birds were fed diets containing one of five dietary Arg concentrations: 9.9, 13.9, 17.6, 21.3, or 25.3 g/kg respectively. The IBDV inoculation significantly reduced (P ＜0.05) serum lysozyme and IgA concentration, mitogen-stimulated peripheral blood mononuclear cell (PBMC) proliferation (Con A), PBMC in vitro NO and H 2 O 2 yield, and serum anti-Newcastle disease virus (NDV) body titers. Increasing Arg concentration linearlyincreased (P＜0.05) serum lysozyme concentration, quadratically increased (P ＜0.05) in vitro PBMC NO yield, linearlyand quadraticallyincreased (P＜0.05) PBMC proliferation (LPS). Serum anti-IBDV antibodytiters tended to be increased quadratically(P＝0.06) byincreasing Arg concentration. The Arg requirement of IBDV inoculated chickens (18.9±0.5) for minimum FCR was higher (P＜0.05) than that of uninoculated chickens (16.0±1.3). The Arg requirements of IBDV inoculated chickens for the highest IgA concentration (17.5±0.6 g/kg) and PBMC proliferation (LPS) (19.8±2.1 g/kg) tended to be higher (P＜0.10) than those for un-inoculated chickens (IgA: 16.1±0.6 g/kg; PBMC proliferation (LPS): 16.3±0.8 g/kg). These results indicate that dietaryArg supplementation mayhave a potential effect in alleviating IBDV-inoculation induced immunosuppression via enhancing the immune function of chickens.