Table 2.

Longitudinal analysis of feed intake, bwt, fecal pH and fecal consistency

Coëfficient	value	SD	P-value
Concentrate + supplement intake (kg)a
Day	0.000	0.040	0.991
Treatment	−0.171	0.855	0.841
Day x treatment	0.001	0.063	0.990
Roughage intake (kg)
Day	0.000	0.015	0.991
Treatment	−0.003	0.320	0.992
Day x treatment	0.000	0.024	0.990
Total feed intake (kg roughage + concentrate + supplement)
Day	−0.001	0.054	0.990
Treatment	−0.175	1.157	0.880
Day x treatment	0.001	0.085	0.990
Bodyweight (kg)
Day	0.773	0.170	< 0.001
Treatment	−17.680	28.895	0.542
Day x treatment	0.331	0.236	0.164
Fecal pH
Day	−0.013	0.005	0.005
Treatment	0.007	0.185	0.970
Day x treatment	−0.005	0.006	0.423
Fecal consistency (1–5 scale)
Day	−0.007	0.006	0.261
Treatment	0.113	0.192	0.560
Day x treatment	−0.008	0.008	0.312

^a Interpretation of longitudinal analysis: Horses in the placebo group ate on average 5.9 kg concentrate mixed with placebo supplement a day over the course of the study. Horses fed the butyrate supplement ate 171 g less on average, but this was not significantly different (P = 0.841)