Author
![]() |
PEEBLES, E - Mississippi State University |
![]() |
JACOB, R - Mississippi State University |
![]() |
Branton, Scott |
![]() |
GERARD, P - Clemson University |
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/20/2014 Publication Date: 6/2/2014 Citation: Peebles, E.D., Jacob, R., Branton, S.L., Gerard, P.D. 2014. Effects of Mycoplasma gallisepticum vaccination on serum a1-acid glycoprotein concentrations in commercial layer chickens. Poultry Science. 93:1396-1402. Interpretive Summary: Increases in circulating acute phase protein (APP) levels, as an integral component of the acute phase response, occur in reaction to systemic infections in animals. However, no previous research has been conducted to monitor possible changes in APP levels of birds in response to pre-lay vaccinations of various live attenuated Mycoplasma gallisepticum (MG) vaccines in conjunction with their subsequent use as an overlay vaccine during the production period for continual protection against field strain MG infections. In the current study, serum concentrations of the APP, a1-acid glycoprotein (AGP), were determined on day 0, 1, 3, 7, 14, and 28 after subjecting commercial laying hens to one of four treatments using either a killed bacterin or a live MG vaccine. Also, at 45 weeks of age the half of the birds were vaccinated with High-passage F-strain MG (HpFMG). Results of this study show that inoculation of chickens with either the killed or live MG vaccines resulted in an elevated AGP concentrations as compared to the non-inoculated Control group. Thus, elevated circulation AGP concentrations may be used to detect and confirm subclinical infections of MG in commercial chickens. Technical Abstract: Increases in circulating acute phase protein (APP) levels, as an integral component of the acute phase response, occur in reaction to systemic infections in animals. However, no previous research has been conducted to monitor possible changes in APP levels of birds in response to pre-lay vaccinations of various live attenuated Mycoplasma gallisepticum (MG) vaccines in conjunction with their subsequent use as an overlay vaccine during the production period for continual protection against field strain MG infections. Serum concentrations of the APP, a1-acid glycoprotein (AGP), were determined on d 0, 1, 3, 7, 14, and 28 after subjecting commercial laying hens to one of the following treatments at 10 woa: 1) Control (no vaccination); 2) ts-11 strain MG (ts11MG) vaccination; 3) MG-bacterin (MGBac) vaccination; and 4) ts11MG and MGBac combination (tsllMG & MGBac) vaccination. Furthermore, at 45 woa, the birds in half of the units assigned to each treatment group were vaccinated with High-passage F-strain MG (HpFMG). Birds in treatment 1 that were (Single Control) and were not (Double Control) vaccinated with HpFMG, and birds in treatments 2, 3, and 4 that were vaccinated with HpFMG were further tested during lay on d 0, 1, 3, 7, 14, and 28 after vaccination. Layer performance is unaffected when pullets are inoculated with ts11MG or MGBac, but is depressed after an HpFMG inoculation during lay. On d 7, 14, and 28 post-vaccination at 10 woa, the ts11MG & MGBac, ts11MG, and MGBac group AGP concentrations were not different from one another, but all were higher than those in the Control group. Similarly, on d 3, 7, and 14 post-vaccination, the Single Control, and the MGBac ts11MG, and tsllMG & MGBac treatment groups that were later vaccinated with HpFMG at 45 woa, were not different, but all were higher than that in the Double Control group. In conclusion, elevated circulation AGP concentrations may be used to detect and confirm subclinical infections in pullets up to 28 d after having been vaccinated with ts11MG, MGBac, or their combination. Furthermore, in association with depressed performance, elevated serum AGP concentrations in layers may be used to confirm HpFMG infections up to 28 d after its use as a vaccine. |