In Jan, 2016, 58 horses from the same yard were divided into 2 groups and housed under either the Equilux lighting system or traditional stable lighting in individual stalls. All horses were on the same training programme that gradually increased in intensity from week 0 to week 15 and consisted of a single exercise bout each day between 7 and 10 am.

Feed composition and energy density was consistent for all horses and there was an equal numbers of colts and fillies in each group. Data on weight and % fat composition were collected at 3‐week intervals and FatFree Mass (FFM) calculated for each horse.

Changes in weight, body fat and FFM over time in horses in training housed under the Equilux system or traditional stable lighting.

During a trial comparing growth parameters in young horses under the Equilux system versus traditional stable lighting, environmental samples of stable air and interior surfaces were collected on weeks 2 and 8.  Samples were cultured and analysed for fungal and bacterial microbes by the Microbiology Department of theIrish Equine Centre.