A pilot study to determine if a dietary mineral supplement can affect reactivity to stimuli by horses in training

Abstract

Trainers have reported horses to be calmer and easier to train after receiving a calcium- and magnesium-rich mineral supplement derived from a calcified algae source. The purpose of this study was to test whether horses receiving this supplement were calmer than horses receiving a placebo. Fourteen 2-year-old Arabians in training were subjected to a ‘moving object reactivity test’ (MORT) and ‘handling reactivity test’ (HRT). The MORT involves quickly raising a bag suspended from the ceiling and scoring horses' reactions. The HRT involves placing horses into breeding stocks and scoring the horses’ nervousness. Horses were equipped with heart rate (HR) monitors and were scored by four observers blinded to treatment. Reactivity scores and HR were used to randomly striate the horses into two groups: a treated group (MIN) receiving 100 g of Aquacid/horse/day and a control group (CO) receiving a placebo. After supplementation for 60 days, horses were retested. Using PROC Mixed, changes from day 0 were examined. In the MORT, CO had an increase of 29 bpm (P=0.001), while MIN only showed a trend to increase (12 bpm; P=0.1). There was no difference between treatments (P=0.12). Reactivity scores during the MORT were not different between treatments (P=0.14) with CO horses increasing by 0.58 (1 to 5 scale) and MIN horses by 0.31. In the HRT, the peak HR of CO increased from day 0 by 17 bpm (P=0.009), but only by 11 bpm in the MIN (P=0.08). Reactivity scores for MIN horses improved by 0.45 (scale from 1 to 4) while the CO worsened by 0.04. Neither HRT measurement was significant (P=0.41 and P=0.33, respectively). Limited treatment differences suggest greater subject numbers were needed due to variability in behavioural responses despite some outcomes favouring MIN. Though inconclusive, results suggest anecdotal claims of calming effects may warrant further investigation.