EVALUATION OF VOLUNTARY INTAKE OF FORAGE TROUGH-FED TO LIGHT HORSES -COMPARISON WITH SHEEP - FACTORS OF VARIATION AND PREDICTION

Voluntary Dry Matter intake (VDMI) in light horses at maintenance was examined after pooling results from 37 fresh and dry forages studied a t INRA and from 42 other drawn from the literature. VDMI were, on the average, in g/kg LW, 12.7 for straws (n = 6), 23.6 for the legume hays (n = 12), 20.4 for the grass hays (n = 38), 20.7 for grass hays regro wth (n = 7) and 20.3 for the fresh forages (n = 16), and, in g/kg LW 0 .75, respectively, 61, 108, 93, 98 and 97. In some comparisons made wi th sheep, we observe that, overall, the VDMI, in g/kg LW, are comparab le for the two species, except in spring/summer when the sheep have a high appetite caused by the season, and that there is no relation betw een the horses and the sheep intakes. VDMI in horses are not influence d by crude protein (CP), crude fibre (CF) or neutral detergent fibre ( NDF). As a result, it is not possible to predict VDMI in horses from t he characteristics of ingested forages. We propose, therefore, to take figures depending of the type of forage: 11-14 g/kg LW for straws, 22 -25 for legume hays, 19-22 for grass hays and fresh forages, 18-21 for grass hays regrowth. (C) 1997 Elsevier Science B.V.