title: Drinking water application of Denagard® Tiamulin for control of Brachyspira pilosicoli infection of laying poultry.
abstract: Avian intestinal spirochaetosis (AIS) caused by Brachyspira spp., and notably Brachyspira pilosicoli, is common in layer flocks and reportedly of increasing incidence in broilers and broiler breeders. Disease manifests as diarrhoea, increased feed consumption, reduced growth rates and occasional mortality in broilers and these signs are shown in layers also associated with a delayed onset of lay, reduced egg weights, faecal staining of eggshells and non-productive ovaries. Treatment with Denagard® Tiamulin has been used to protect against B. pilosicoli colonisation, persistence and clinical presentation of AIS in commercial layers, but to date there has been no definitive study validating efficacy. Here, we used a poultry model of B. pilosicoli infection of layers to compare the impact of three doses of Denagard® Tiamulin. Four groups of thirty 17 week old commercial pre-lay birds were all challenged with B. pilosicoli strain B2904 with three oral doses two days apart. All birds were colonised within 2 days after the final oral challenge and mild onset of clinical signs were observed thereafter. A fifth group that was unchallenged and untreated was also included for comparison as healthy birds. Five days after the final oral Brachypira challenge three groups were given Denagard® Tiamulin in drinking water made up following the manufacturer's recommendations with doses verified as 58.7 ppm, 113 ppm and 225 ppm. Weight gain body condition and the level of diarrhoea of birds infected with B. pilosicoli were improved and shedding of the organism reduced significantly (p=0.001) following treatment with Denagard® Tiamulin irrespective of dose given. The level and duration of colonisation of organs of birds infected with B. pilosicoli was also reduced. Confirming previous findings we showed that the ileum, caeca, colon, and both liver and spleen were colonised and here we demonstrated that treatment with Denagard® Tiamulin resulted in significant reduction in the numbers of Brachyspira found in each of these sites and dramatic reduction in faecal shedding (p<0.001) to approaching zero as assessed by culture of cloacal swabs. Although the number of eggs produced per bird and the level of eggshell staining appeared unaffected, egg weights of treated birds were greater than those of untreated birds for a period of approximately two weeks following treatment. These data conclusively demonstrate the effectiveness of Denagard® Tiamulin in reducing B. pilosicoli infection in laying hens.
authors.affiliation: Department of Food and Nutritional Sciences, School of Chemistry, Food and Pharmacy, University of Reading, Whiteknights Parks, P.O. Box 226, Reading RG6 6AP, UK.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Woodward
authors.affiliation: Department of Food and Nutritional Sciences, School of Chemistry, Food and Pharmacy, University of Reading, Whiteknights Parks, P.O. Box 226, Reading RG6 6AP, UK.
authors.forename: Luke
authors.initials: L
authors.lastname: Mappley
authors.affiliation: Department of Food and Nutritional Sciences, School of Chemistry, Food and Pharmacy, University of Reading, Whiteknights Parks, P.O. Box 226, Reading RG6 6AP, UK.
authors.forename: Caroline
authors.initials: C
authors.lastname: Le Roy
authors.affiliation: Department of Food and Nutritional Sciences, School of Chemistry, Food and Pharmacy, University of Reading, Whiteknights Parks, P.O. Box 226, Reading RG6 6AP, UK.
authors.forename: Sandrine P
authors.initials: SP
authors.lastname: Claus
authors.affiliation: Animal Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Davies
authors.affiliation: Animal Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: Gavin
authors.initials: G
authors.lastname: Thompson
authors.affiliation: Animal Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.
authors.forename: Roberto M
authors.initials: RM
authors.lastname: La Ragione
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D017400:Brachyspira / Q000187:drug effects*; D002645:Chickens; D004224:Diterpenes / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D060766:Drinking Water / Q000032:analysis*; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D011201:Poultry Diseases / Q000188:drug therapy* / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D004224:Diterpenes; D060766:Drinking Water; C014224:tiamulin
keywords: Avian intestinal spirochaetosis (AIS); Brachyspira pilosicoli; Denagard® Tiamulin; Poultry model and treatment regime for AIS