Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2008
Publication Date: 4/2/2008
Citation: Viscoine, K.A., Branton, S.L., Gerard, P.D., Whitmarsh, S.K., Peebles, E.D. 2008. Effects of a Prelay 6/85-strain Mycoplasma gallisepticum Inoculation Alone or in Conjunction with Subsepuent F-Strain Mycoplasma gallisepticum Inoculation During Lay on the Internal Egg Characteristics of ...... Poultry Science 87:1120-1124. Interpretive Summary: Mycoplasma gallisepticum (MG) is a bacteria that infects approximately 85% of the commercial table egg layer chickens in the U.S. Once infected, chickens remain infected for life and no antibiotic is effective in removing it from the chicken. Its presence is estimated to cost the industry in excess of $140 million annually with the loss primarily attributable to decreased egg production of approximately 16 eggs/hen although internal egg characteristics are also impacted. Three commercial vaccines are available to the poultry industry’s layer sector to combat these losses. However, each of these vaccines has specific strengths and weaknesses with none being an “ideal” vaccine. The present study was conducted to determine whether the use of two of the three vaccines used in conjunction with one another would provide better protection than either used singly. Results of this study show that changes were observed in layer yolk fatty acid profiles in response to prelay inoculation with either one vaccine alone or in conjunction with inoculation with the second vaccine during lay and these changes may be manifested by disturbances in fatty acid synthesis. These results may ultimately aid understanding of the physiological changes induced in the chicken by the organism.
Technical Abstract: The effects of a pre-lay 6/85-strain M. gallisepticum (6/85MG) inoculation alone or in conjunction with F-strain M. gallisepticum (FMG) inoculation overlays during lay on the internal egg characteristics of commercial egg laying hens were investigated. In the first 2 treatment groups, birds were sham inoculated or were inoculated with 6/85MG at 10 wk of age. In a third treatment group, birds were inoculated with 6/85MG at 10 wk in conjunction with an overlay of FMG at 22 wk, and in a fourth treatment group, birds were inoculated with 6/85MG at 10 wk in conjunction with an overlay of FMG at 45 wk. Percentage yolk weight, albumen weight, yolk moisture, and yolk lipid were determined at 24, 32, 43, 47, and 58 wk of hen age. The data from wk 24, 32, and 43 was analyzed separately from that at wk 47 and 58. Furthermore, yolk fatty acid profiles were determined at wk 58. The applied treatments affected yolk moisture and fatty acid profiles. Across wk 24, 32, and 43, yolk moisture content was higher in birds inoculated with 6/85MG at 10 wk and FMG at 22 wk when compared to control birds and those inoculated with 6/85MG at 10 wk alone. Also, at wk 58, yolk palmitic, oleic, and linolenic acid concentrations were affected differently by treatment. A 22 wk FMG inoculation in birds previously inoculated with 6/85MG at 10 wk may increase yolk moisture content, and alterations in yolk palmitic, oleic, and linolenic acid levels with treatment may become manifested by disturbances in fatty acid synthesis.