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Research article - Peer-reviewed, 2021

Increased body fat content in horses alters metabolic and physiological exercise response, decreases performance, and increases locomotion asymmetry

Jansson, Anna; Gunnarsson, Vikingur Th; Ringmark, Sara; Ragnarsson, Sveinn; Soderroos, Denise; Asgeirsson, Einar; Johannsdottir, Tanja R.; Liedberg, Charlotta; Stefansdottir, Gudrun J.;

Abstract

This study examined the effect of altered body weight (BW) and body fat content on exercise performance and recovery. Nine horses were divided into two groups, and changes in BW and fat content were induced by feeding a high (HA) or restricted (RA) energy allowance for 36 days in a cross-over design. In the last week of each treatment, BW and body condition score (BCS) were recorded, body fat percentage was estimated using ultrasound, and a standardized incremental treadmill exercise test (SET) and competition-like field test were performed (scored by judges blinded to treatments). Blood samples were collected, and heart rate (HR), rectal temperature (RT), and respiratory rate (RR) were also recorded. Objective locomotion analyses were performed before and after the field test. Body weight, body fat percentage, and BCS were higher (5-8%) in HA than in RA horses (p < 0.05). In SET, HA horses showed higher HR, plasma lactate concentration, RR, and RT than RA horses (p < 0.05), and lower VLa4, hematocrit (Hct), plasma glucose, and plasma NEFA concentrations (p < 0.05). Hct was also lower in HA horses in the field test, while RA horses showed higher scores (p < 0.05). After both tests, resting plasma lactate concentrations were reached faster in RA than in HA horses (p < 0.05). Objective locomotion asymmetry was higher in HA than in RA (p < 0.05). These results clearly show that increased BW and body fat content in horses lower physiological fitness in terms of VLa4, plasma lactate removal, Hct levels, plasma glucose availability and reduce true performance evaluated by blinded judges.

Keywords

body fat; hematocrit; lactate threshold; locomotion symmetry; performance

Published in

Physiological Reports

2021, volume: 9, number: 11, article number: e14824

Authors' information

Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry (AFB)
Gunnarsson, Vikingur Th
Holar Univ
Ragnarsson, Sveinn
Hólar University College
Hólar University College
Asgeirsson, Einar
Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry (AFB)
Jóhannsdòttir, Tanja
Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry (AFB)
Liedberg, Charlotta
No organisation
Stefánsdóttir, Gudrún
Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry (AFB)
Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry (AFB)

UKÄ Subject classification

Medical Bioscience

Publication Identifiers

DOI: https://doi.org/10.14814/phy2.14824

URI (permanent link to this page)

https://res.slu.se/id/publ/112775