title: Effect of induced molting on the course of infection and transmission of Salmonella enteritidis in white Leghorn hens of different ages.
abstract: Previous work in the authors' laboratory had shown that inducing molt using a 2-wk feed removal protocol in 58- to 84-wk-old White Leghorn hens increased the severity of intestinal infection by Salmonella enteritidis (SE). As susceptibility to infection can be influenced by age, a study was conducted to compare the effect of the feed removal on infection by SE in 20-, 40-, and 74-wk-old hens. Birds were orally infected with 5 to 10 x 10(6) SE on Day 4 of fast and were sampled for SE shedding 3, 10, 17, and 24 days later. Significantly higher numbers of SE were shed in fasted birds on Day 3 (20 and 40 wk of age), Day 10 (40 and 74 wk of age), and Day 17 (74 wk of age). Transmission of SE to uninfected, contact-exposed birds was observed in all three trials for both the fed and fasted groups. However, significantly more fasted contact-exposed birds became positive for SE on Day 3 (20-wk-old), Day 10 (74-wk-old), and Day 17 (74-wk-old). Significantly more SE was also shed in these fasted contact-exposed birds on Day 3 (20-wk-old), Day 10 (all age groups), and Day 17 (74-wk-old). The current results indicate that the fasting conditions used to induce a molt in hens increase the shedding of SE in direct-infected and contact-exposed hens and this effect does not appear to be affected by age.
authors.affiliation: U.S. Department of Agriculture, Southeast Poultry Research Laboratory, Athens, Georgia 30605.
authors.forename: P S
authors.initials: PS
authors.lastname: Holt
authors.forename: R E
authors.initials: RE
authors.lastname: Porter
mesh_terms: D000375:Aging / Q000502:physiology; D000822:Animal Husbandry; D000818:Animals; D002645:Chickens / Q000502:physiology*; D004198:Disease Susceptibility; D005215:Fasting / Q000502:physiology; D005241:Feathers / Q000502:physiology*; D005260:Female; D011201:Poultry Diseases / Q000382:microbiology / Q000503:physiopathology* / Q000635:transmission; D012481:Salmonella Infections, Animal / Q000503:physiopathology* / Q000635:transmission; D012477:Salmonella enteritidis