The energy requirements of performance horses in training

This is one of those articles that I read then wonder what to do with. Does it provide information that my members can use? At the least it reminds us of the basic tenet of equine nutrition: feed the horse not the nutrition tables, see the Overview Article for what this means. However we all have to make estimates of changes in feeding when their are changes in the horse’s circumstances and work. This summary provides an update to guidelines of how much more energy is needed for exercise. Surprising was how similar energy changes were across various disciplines. Certainly the energy expenditure for the endurance horse in training is greater than the dressage horse but you know that already. The publishers of this article have allowed republishing of this article so we have placed it in the topic associated with this discussion area. Though a bit technical it is full of insightful observations and adds greatly to the topic.
DrO

The energy requirements of performance horses in training
Transl Anim Sci. 2020 Mar 17;
Authors: Mark Ebert 1 , Meriel J S Moore-Colyer 1
Affiliation
1 School of Equine Management and Science, Royal Agricultural University, Cirencester GL, UK.
Abstract
The aim of this study was to estimate the energy requirements of performance horses in active, variable training in the field. Sixty horses in England and Switzerland were measured over 2-wk periods and, for 15 of these, the measurement period was extended, ranging from 21 to 42 wk. Energy intake was estimated by measuring daily feed consumption. Energy output was measured using heart rate (HR) monitors during 608 training sessions, relating HR to volume of oxygen (VO₂) and converting VO₂ to energy. Field maintenance requirements were calculated by deducting the marginal energy cost of training from energy input. The mean field maintenance expenditure for performance horses with a normal temperament was found to be 0.118 MJ of metabolizable energy (ME) per kilogram of body weight (BW) per day (SD = 0.008, CI = 0.005, n = 60 horses). This result is between 1.9% (P = 0.086) and 20.9% (P < 0.001) greater than the official guidance found in the United States, France, Germany, and Holland. Heart rate monitoring of training revealed a mean energy expenditure (EE) per ridden session of 0.023 MJ ME (SD = 0.001, CI = 0.001, n = 175 training sessions). The mean daily EE for exercise based on a full week’s training was 0.018 MJ ME/kg BW/d (SD = 0.005, CI = 0.001, n = 60 horses), representing a multiple of maintenance of 15.3%. This implies that the official guidance in the United States and France may overstate expenditure for exercise by 111% and 15%, respectively (P < 0.01). Daily EE between countries and within disciplines was consistent, allowing for the creation of user-friendly tables that can be used in budgeting the energy component of diets.