title: Effect of soy on faecal dry matter content and excretion of Brachyspira hyodysenteriae in pigs.
abstract: The aim of this study was to investigate the effect of a soy diet on the excretion of Brachyspira hyodysenteriae in five farms with subclinically infected pigs. The effects on general health, faecal consistency and dry matter were analysed. In total, 200 pigs of different ages (group 1 <100 days of age (n=120) and group 2 ≥100 days (n=80)) were randomly assigned to the control (C) and the treatment (T) groups. Group C received the farm's standard diet. In group T half of the daily feed ration was replaced by pure soy on two consecutive days. Faecal scores were used to determine faecal consistency and a microwave method to assess faecal dry matter content (FDMC). In age group 1, soy feeding resulted in a statistically significant decrease of the FDMC of 2.5 per cent compared with group C and in age group 2 in a significant increase of 2.2 per cent compared with group C at day 2. Overall seven (T: 5, C: 2) out of 597 faecal samples tested positive for B hyodysenteriae by PCR. In conclusion, a high soy diet applied over two days influenced the faecal consistency and the FDMC in growers, finishers and sows under field conditions. Further investigations with more sensitive diagnostic methods are needed to prove a potential influence of a high soy diet on the detection rate of B hyodysenteriae in subclinically infected herds.
authors.affiliation: Department of Clinical Veterinary Medicine, Vetsuisse Faculty , Clinic for Swine, University of Bern , Bern , Switzerland.
authors.forename: Alexander
authors.initials: A
authors.lastname: Grahofer
authors.affiliation: Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty , Institute of Veterinary Bacteriology, University of Bern , Bern , Switzerland.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Overesch
authors.affiliation: Department of Clinical Veterinary Medicine, Vetsuisse Faculty , Clinic for Swine, University of Bern , Bern , Switzerland.
authors.forename: Heiko
authors.initials: H
authors.lastname: Nathues
authors.affiliation: Department of Clinical Veterinary Medicine, Vetsuisse Faculty , Clinic for Swine, University of Bern , Bern , Switzerland.
authors.forename: Friederike
authors.initials: F
authors.lastname: Zeeh
keywords: Bacterial diseases; Diagnostics; Enteric disease; Nutrition; Pigs; Spirochaetes