Submitted to: American Journal of Veterinary Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/1996
Publication Date: N/A
Interpretive Summary: Induced molting is a procedure used by greater than 60% - 70% of the layer industry to achieve a second egg-laying cycle from their flocks. A molt is generally induced through the removal of feed for 10-14 days which causes the birds to cease egg lay for a period of time. Our laboratory had previously shown that induced molting made the hens more susceptible to Salmonella enteritidis (SE) and increased the severity of the infectio by this organism. The question we asked was how soon after the hens are infected will the increased severity be seen. We found that damage within the large intestine was substantially higher in molted hens 48 hours after infection. In one experiment, the small intesting from molted hens also showed substantial damage compared with unmolted hens. These results are important to the layer industry since they show that a prevalent industry procedure has a substantial effect on the severity of an SE infection and these effects are observed early in the disease process. Also, many organisms infect poultry and if molting has such rapid effects on an infection by SE, it is very possible that it could have similar effects on infection by other poultry disease agents.
Technical Abstract: The present study was conducted to describe and compare early inflammation caused by Salmonella enteritidis in molted and non-molted hens. Adult white leghorn chickens were orally infected with Salmonella enteritidis at 4 days after feed removal. At 2,4,8,10,24,48,72, and 96 hours after infection hens were euthanized and the duodenum, jejunum, ileum, cecum and d colon were evaluated by light microscopy. Inflammation occurred more frequently and was significantly greater in the cecum and colon of molted- infected hens, compared to non-molted-infected hens beginning at 48 hours after infection. In one trial, inflammation was consistently higher in the ileum of molted-infected hens compared to non-molted-infected hens.