Biochemical and immunological responses of young turkeys to vaccination against Ornithobacterium rhinotraheale and different levels of dietary methionine

Abstract

The objective of this study was to verify the hypothesis that increasing levels of dietary methionine can stimulate the mechanisms of cell-mediated and humoral immunity in young turkeys. The blood and organs involved in cell-mediated and humoral immune responses were analyzed in 8-week-old turkeys that had been vaccinated against Ornithobacterium rhinotraheale (ORT) infection (on days 17 and 48). The birds were fed diets with a low (LM), medium (MM) and high (HM) methionine content (0.45 and 0.40%, 0.60 and 0.51%, 0.71 and 0.57% in weeks 1 -4 and 5 -8, respectively).Dietary methionine supplementation led to a significant increase in body weights of turkeys at 56 days of age, from 3532 g in group LM to 3720 g in group MM and 3760 g in group HM (p=0.001). A significant increase in vaccine-induced antibody titers against ORT was noted in group HM relative to group LM (p=0.006). Increasing levels of methionine had no significant effect on total serum IgG nor IgM levels and most serum biochemical parameters, TP, ALB, GLOB, GLU, AST, ALP, P and Ca. In comparison with group LM, group HM turkeys were characterized by a lower percentage of IgM + B cell subpopulation in the blood and bursa of Fabricius.The percentages of CD4 + and CD8 + T cell subpopulations in the bursa of Fabricius in group HM were significantly different from those found in groups LM and MM. The highest percentages of CD4 + T cells and CD8 + T cells in the spleen were observed in groups LM (p<0.001) and HM (p=0.04), respectively. The differences were statistically significant relative to the remaining groups. Turkeys of group LM were characterized by a lower CD4 + T cell percentage in the thymus (p<0.001) and a lower CD8 + T cell percentage in the cecal tonsils (CTs) (p<0.01).Vaccination against ORT resulted in a significant increase in the percentage of CD4 + /CD8 + T cell subpopulation and a decrease in the percentage of CD8 + T cell subset in the spleen.

Growth rate and metabolic parameters in young turkeys fed diets with different inclusion levels of methionine

“…In our study, similarly to earlier experiments with chickens (Deng et al, 2007;Rubin et al, 2007;Bouyeh, 2012) and turkeys (Kubińska et al, 2015b), the diet containing no supplemental DL-Met contributed to a decrease in BWG, in comparison with birds fed diets supplemented with Met at levels being in line with NRC (1994) recommendations. Dietary Met concentrations higher than the levels recommended by NRC (1994) and B.U.T.…”

“…Similarly to experiments with chickens (Rubin et al, 2007;Bouyeh, 2012), the diet without DL-Met deteriorated feed conversion, but only in the first month of feeding. In the previous experiments with turkeys, diets without DL-Met supplementation had no adverse effect on the growth performance of four-week-old birds , but they decreased the BWG of eight-week-old birds (Kubińska et al, 2015b).…”

Research Note: Effect of age on the distribution of lymphocytes in the oviduct in Turkey breeder hens

“…The results of flow cytometry analysis of spleen and blood mononuclear cells provided in our study are similar to the findings reported by Kubińska et al. (2014) .…”

The immune response of young turkeys to haemorrhagic enteritis virus infection at different levels and sources of methionine in the diet

“…This is expected to alleviate negative outcomes of HEV and improve the birds health status and resultantly (by decreasing amounts of antibiotics used) to improve turkey production effectiveness and quality of poultry products. The substances with proved, positive impact on the immune system of poultry and their body weight gains include, i.a., vitamins, probiotics, essential oils, herbs, nucleotides, and amino acids [4, 18, 19].…”