Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 9, 2002
Publication Date: August 19, 2002
Citation: Holt, P.S., Gast, R.K. 2002. Comparison of the effects of infection with salmonella enteritidis, in combination with an induced molt, on serum levels of the acute phase protein, alphal acid glycoprotein in hens. Poultry Science. Interpretive Summary: For a number of years, researchers and clinicians have used acute phase proteins (APP) as indicators of inflammation and infection in humans and other mammalian species. We wanted to see if the chicken APP, alpha 1 acid glycoprotein (AGP), could be used as an indicator of problems with Salmonella enteritidis (SE) during the potentially high stress situation of fmolting. Approximately 70% of US layer flocks are molted annually to get second egg lay from older hens in declining lay. We showed previously that this procedure increased the severity of SE infections in hens. In the current study, levels of serum AGP generally increased in infected hens compared with their uninfected counterparts and these levels increased dramatically in molted infected hens. Serum AGP may be an important method for producers to use to inform them of potential infection problems in their flocks during the stress of molt.
Technical Abstract: Periods of inflammation due to infection, injury, or malignancy are marked by increases in serum constituents known as acute phase proteins (APP) and these proteins have been used as markers for early stages of disease. Four experiments were performed to examine whether levels in chickens of one such APP, alpha-1-acid glycoprotein (AGP), would be affected by an infection with Salmonella enteritidis (SE) and if added stress of induced molting via 14-day feed withdrawal would increase these effects. In all experiments but Experiment 1, hens were divided into 4 equal groups: molt infected, unmolt infected, molt uninfected, unmolt uninfected. Blood and intestinal samples were collected at various times from the hens and assayed for AGP and SE levels, respectively. Infection with SE elevated serum AGP levels above those found in the uninfected groups of hens in two of four experiments while in molted infected hens, serum AGP levels were significantly higher than those found in the uninfected counterparts in al 4 experiments. Significantly higher SE levels generally did not guarantee significantly higher AGP ;levels althouhg when individual values were plotted, a trend toward increasing serum levels show concomitant with increasing SE counts were observed. Serum AGP levels show promise as a method to detect infection problems in hens especially when the severity of the infection is exacerbated by stress situations.