|
|
||||||||
IMMUNOLOGY, HEALTH, AND DISEASE: Research Notes |



* Department of Poultry Science, Mississippi State University, and
Poultry Research Unit, Agricultural Research Service, USDA, Mississippi State, MS 39762; and
Department of Applied Economics and Statistics, Clemson University, Clemson, SC 29634
3 Corresponding author: dpeebles{at}poultry.msstate.edu
Two trials were conducted to determine the effects of a prelay 6/85-strain Mycoplasma gallisepticum (6/85MG) vaccination alone or in conjunction with time-specific F-strain M. gallisepticum (FMG) inoculation overlays on the gross reproductive and digestive organ characteristics of commercial egg-laying hens. In each trial, the following 4 treatments were applied: 1) sham vaccination at 10 wk of age; 2) vaccination of 6/85MG at 10 wk; 3) 6/85MG at 10 wk overlaid by FMG inoculation at 22 wk; and 4) 6/85MG at 10 wk overlaid by FMG at 45 wk. Two birds per isolation pen (experimental replicate unit) were necropsied at the end of both trials to observe the effects of treatment on liver weight, liver lipid and moisture concentrations, incidence of fatty liver hemorrhagic syndrome, ovary weight, mature ovarian follicle numbers, and the total and segmental weights, lengths, and histologies of the oviduct and small intestine. The applied treatments affected only liver moisture. Liver moisture content was greater in birds vaccinated with 6/85MG at 10 wk alone or in conjunction with FMG at 45 wk in comparison with sham vaccinated controls and birds that received a 6/85MG vaccination at 10 wk overlaid by an FMG inoculation at 22 wk. Prelay 6/85MG vaccinations may be a suitable substitute for prelay FMG inoculations, and FMG overlays during lay on prelay 6/85MG vaccinations may also provide continual protection against field-strain MG infections without eliciting any subsequent suppressive effects on performance, as noted in an earlier study.
Key Words: digestive organ F-strain Mycoplasma gallisepticum inoculation reproductive organ 6/85-strain Mycoplasma gallisepticum
1 This is Journal No. J-11429 from the Mississippi Agricultural and Forestry Experiment station supported by MIS-321010.
2 Use of trade names in this publication does not imply endorsement by Mississippi Agricultural and Forestry Experiment Station of these products, nor similar ones not mentioned.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |