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No Protective Effects of High-Dosage Dietary Zinc Oxide on Weaned Pigs Infected with Salmonella enterica Serovar Typhimurium DT104
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| Zeitschriftentitel: | Applied and Environmental Microbiology |
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| Personen und Körperschaften: | , , , , |
| In: | Applied and Environmental Microbiology, 79, 2013, 9, S. 2914-2921 |
| Format: | E-Article |
| Sprache: | Englisch |
| veröffentlicht: |
American Society for Microbiology
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| Schlagwörter: |
| Zusammenfassung: | <jats:title>ABSTRACT</jats:title> <jats:p> Twenty-eight-day-old weaned pigs were fed diets with a low (LZn), medium (MZn), or high (MZn) Zn concentration (50 to 80, 150, or 2,500 mg Zn/kg of diet, respectively) provided as zinc oxide (ZnO)(24 pigs per group). They were infected orally with <jats:named-content content-type="genus-species">Salmonella enterica</jats:named-content> serovar Typhimurium DT104 on day 32. Salmonellae were cultivated from feces (up to 42 days postinfection [dpi]) and organs (2 and 42 dpi). Activation of the adaptive systemic and mucosal immune systems was investigated by recording anti- <jats:named-content content-type="genus-species">Salmonella</jats:named-content> IgG levels and levels of B and T lymphocyte subpopulations in blood and gut-associated lymphatic tissue. Growth performance was recorded as well. Salmonellae were shed at higher levels and for longer periods in the HZn group ( <jats:italic>P</jats:italic> < 0.05), with no differences in the tissues. At 2 dpi, the relative percentages of CD4 <jats:sup>+</jats:sup> T helper cells ( <jats:italic>P</jats:italic> < 0.01) and of CD2 <jats:sup>+</jats:sup> T and NK cells ( <jats:italic>P</jats:italic> < 0.01) in blood were reduced from the relative cell counts obtained at 0 dpi, irrespective of the Zn group. The lowest percentage of cytotoxic T cells was found 14 dpi in the HZn group relative to the MZn ( <jats:italic>P</jats:italic> < 0.05) and LZn ( <jats:italic>P</jats:italic> < 0.01) groups. Supplementation of the feed with 2,500 mg Zn/kg of diet immediately after weaning could positively affect the immune responses of piglets infected with <jats:named-content content-type="genus-species">Salmonella</jats:named-content> Typhimurium, but for a short period only. After 2 weeks, all positive effects disappeared, and rather negative effects, such as higher shedding of salmonellae, lower T cell frequencies, and worse performance, occurred. Thus, supplementation with ZnO at high levels in the pig industry should be limited to 2 to 3 weeks. </jats:p> |
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| Umfang: | 2914-2921 |
| ISSN: |
1098-5336
0099-2240 |
| DOI: | 10.1128/aem.03577-12 |