Effects of Salmonella typhymurium Lipopolysaccharide Challenge on the Performance, Immune Responses and Zinc Metabolism of Laying Hens Supplemented with Two Zinc Sources

Tingshui Cheng,Yuming Guo

doi:10.5713/ajas.2004.1717

Abstract

The study was conducted to determine the effect of Salmonella typhymurium lipopolysaccharide (LPS) challenge on egg-laying performance, inflammatory response, zinc metabolism in layer fed diets supplemented with organic or inorganic zinc since 3- wk-old. The three dietary treatments were corn-soybean meal basal diet without supplemental zinc or with supplemental zinc at 60 mg/kg zinc from ZnSO4 or zinc amino acid complex (ZnAA). At the age of 58 wk-old, twelve hens from each dietary treatment were allotted into two sub-groups. On day 1, 3, 5, 7 of the 58 th week of age, six birds of one sub-group were injected intraperitoneally (i.p.) with 2 ml LPS (1.0 µg/ml) or sterile saline. Neither zinc source × immune challenge interaction nor zinc source effect on egg production performance was observed (p>0.05), LPS-challenge decreased egg production (p 0.05). Supplementation of 60 mg/kg zinc from either ZnAA or ZnSO4 significantly (p<0.05) elevated metallothionein (MT) concentration in liver and spleen. MT concentration in liver of birds fed ZnAA diet was higher than in those fed ZnSO4 diet (p<0.05). The magnitude of increase of hepatic and splenic MT due to LPS challenge was higher by supplementation of ZnAA than ZnSO4. The results suggest that zinc amino acid complex enhanceed MT synthesis and zinc sequestered in liver and spleen and increased the sensitivity to immune response due to LPS challenge. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 12 : 1717-1724)

Highlights

In the early 1960s, zinc was first identified as an essential element, and as an integral part of more than 300 enzyme systems that are involved in major metabolic pathways
The results suggest that zinc amino acid complex enhanceed MT
The main objective of the present work was to investigate the laying performance and immune responses, and distributions of zinc and MT in both lymphoid and nonlymphoid organs of laying hens during immune stress induced by Salmonella typhymurium LPS challenge

Summary

Introduction

In the early 1960s, zinc was first identified as an essential element, and as an integral part of more than 300 enzyme systems that are involved in major metabolic pathways. Its extreme important role in normal development, maintenance and function of immune systems is widely accepted Zinc deficiency is manifested by lymphoid atrophy, lymphopenia and alterations in the proportions and functional activities of the various subsets of lymphocytes and mononuclear phagocytes. Zinc repletion may correct the majority of observed change in immune function due to Zn deficiency (Wellinghausen et al., 1997). Potential benefits of organic zinc complexes on the immune function

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