Fecha/hora: 15/06/2024 18:36:14

Biblioteca(s): 	INIA Las Brujas.	
Fecha corriente: 	24/10/2014	
Fecha de la última actualización: 	30/10/2019	
Autoria: 	MEDEROS, A.; FERNÁNDEZ, S.; VanLEEUWEN, J.; PEREGRINE, A.S.; KELTON, D.; MENZIES, P.; LeBOEUF, A.; MARTIN, R.	
Afiliación: 	AMERICA ESTHER MEDEROS SILVEIRA, Instituto Nacional de Investigación Agropecuaria (INIA), Uruguay; S. FERNÁNDEZ, Dept. of Pathobiology, Ontario Veterinary College, University of Guelph, Canada; J. VanLEEUWEN, Dept. of Health Management, University of Prince Edward Island, Charlottetown, Canada; A.S. PEREGRINE, Dept. of Pathobiology, Ontario Veterinary College, University of Guelph, Canada; D. KELTON, Dept. of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Canada; P. MENZIES, Dept. of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Canada; A. LeBOEUF, Centre d’Expertise en Production Ovine du Québec, La Pocatière, Canada; R. MARTIN, Organic Agriculture Centre of Canada, Nova Scotia Agricultural College, Truro, Canada.	
Título: 	Prevalence and distribution of gastrointestinal nematodes on 32 organic and conventional commercial sheep farms in Ontario and Quebec, Canada (2006-2008).	
Año de publicación: 	2010	
Fuente/Imprenta: 	Veterinary Parasitology, 2010, v. 170, no.3-4, p. 244-252.	
ISSN: 	0304-4017	
DOI: 	10.1016/j.vetpar.2010.02.018	
Idioma: 	Inglés	
Notas: 	Article history: Received 5 August 2009 / Received in revised form 28 December 2009 / Accepted 11 February 2010.	
Contenido: 	ABSTRACT.

In order to characterize the epidemiology of sheep gastrointestinal nematodes in organic and conventional flocks in Canada, a longitudinal study was carried out from May 2006 to March 2008 on 32 purposively selected farms in Ontario (ON) and Quebec (QC): 8 certified organic (CO), 16 non-certified organic (NCO), and 8 conventional (C) farms. On each farm, 10 ewes and 10 female lambs were selected. Farm visits were undertaken monthly during the grazing season, and twice in the winter. At each visit, individual fecal samples were taken, and pasture samples were obtained during the grazing season. In addition, body condition score was recorded for all sheep. Fecal egg counts per gram of feces (EPGs) were determined for all fecal samples, and infective larvae (L 3) were identified in fecal samples (lambs and ewes separately) and pasture samples from farms. Necropsies of 14 lambs from 7 of the 23 Ontario farms were performed at the end of the grazing season in 2006. The mean EPG for year 1 (May 2006 to March 2007) was 181 (range=0-9840) and 351 (range=0-18,940) for the ewes in ON and QC, respectively, and for the lambs was 509 (range=0-25,020) and 147 (range=0-3060) for ON and QC, respectively. During year 2 (April 2007 to March 2008), the mean EPG was 303 (range=0-21,160) and 512 (range=0-22,340) for the ewes in ON and QC, respectively, and for lambs was 460 (range=0-26,180) and 232 (range=0-8280) for ON and QC, respectively. Although the overall mean EPGs were not remarkably high, there were months of higher EPG such as May-June for ewes and July-August for lambs in both provinces. Pasture infectivity was highest in May-June and September. There was a general trend for the CO farms to have lower mean EPG than NCO and C farms.Fecal cultures demonstrated that the most predominant nematode genera were Teladorsagia sp., Haemonchus sp. and Trichostrongylus spp. Pasture infectivity was highest during June-July (984 L3/kg. DM) in ON farms and September (mean = 436 L3/kg. DM) in QC farms during year 1. In year 2, the highest peak was during October in ON (mean = 398 L3/kg. DM) and July in QC (239 L3/kg. DM). Trichostrongylus axei and Trichostrongylus colubriformis were the species most frequently identified from necropsies (36.44% and 38.26%, respectively) at the end of the grazing season in 2006, with Haemonchus contortus and Teladorsagia circumcincta being the next most commonly identified. 
© 2010 Elsevier B.V.	
Thesagro: 	ANTIHELMÍNTICOS; CORDEROS; NEMATODOS GASTROINTESTINALES; NEMÁTODOS GASTROINTESTINALES DE LOS OVINOS; OVEJAS.	
Categoría del tema: 	L73 Enfermedades de los animales	
Registro original: 	INIA Las Brujas (LB)	
Ejemplares: 	LB - (100228-1) - PXI - AP - DD - PP/VETERINARY PARASIT./2010 -  -  - DIS