title: Considerations for the use of restricted, soaked grass hay diets to promote weight loss in the management of equine metabolic syndrome and obesity.
abstract: The addition of hay soaking to current nutritional advice for weight loss management for equine obesity lacks clinical evidence. Twelve overweight/obese horses and ponies were used to test the hypothesis that feeding soaked hay at 1.25% of body mass (BM) daily as dry matter (DM) before soaking would elicit weight losses within the target 0.5-1.0% of BM weekly. Six animals were used to evaluate the impact of nutrient-leaching on the digestibility and daily intakes of dietary energy and nutrients. Soaked hay DM was corrected in accordance with the 'insoluble' ADF content of fresh and soaked hays. The ADF-based method was validated using a test-soaking protocol. Animals fed soaked hay for 6 weeks lost 0.98 ± 0.10% of BM weekly. The most weight loss sensitive animal lost ~2% of BM weekly. Soaking hay did not alter DM gross energy concentrations, incurred losses of water soluble carbohydrates (WSC) and ash and increased acid detergent fibre (ADF) concentrations. Digestibilities of GE, DM, ash and WSC were unaltered but soaking increased uncorrected values for crude protein (+12%) and ADF (+13.5%) digestibility. Corrected DM provision was only 1% of BM daily, providing 64% of maintenance DE requirements, a 23.5% increase in the intended magnitude of energy restriction. Hay soaking leached nutrients, reduced DM and DE provision and was associated with accelerated weight losses over those expected had fresh-hay been fed to the same level. The ADF-based method will allow the predictive evaluation of individual hays to direct feeding management and prevent inadvertently severe DM and energy restriction.
authors.affiliation: School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Manor Park Campus, Guildford GU2 7AL, UK. Electronic address: c.argo@surrey.ac.uk.
authors.forename: Caroline McG
authors.initials: CM
authors.lastname: Argo
authors.affiliation: School of Veterinary Science, University of Liverpool, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE, UK.
authors.forename: Alexandra H A
authors.initials: AH
authors.lastname: Dugdale
authors.affiliation: Department of Musculoskeletal Biology, Faculty of Health and Life Sciences, University of Liverpool, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE, UK.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: McGowan
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D031204:Caloric Restriction / Q000662:veterinary*; D004032:Diet / Q000662:veterinary; D006734:Horse Diseases / Q000178:diet therapy*; D006736:Horses; D024821:Metabolic Syndrome / Q000178:diet therapy / Q000662:veterinary*; D009765:Obesity / Q000178:diet therapy / Q000662:veterinary*; D006109:Poaceae; D014867:Water; D015431:Weight Loss / Q000502:physiology
chemical_list: D014867:Water
keywords: Dietary restriction; EMS; Equine obesity; Soaked hay; Weight loss; Weight loss resistance