COMPARED FEEDING PATTERNS IN AD-LIBITUM INTAKE OF DRY FORAGES BY HORSES AND SHEEP

Two trials were performed to compare voluntary dry matter intake and f eeding behaviour in adult gelding saddle horses, weighing 500 kg, and adult sheep, weighing 70 kg. In each trial, 4 grass hays, 1 lucerne ha y and 1 straw were given to the animals. On average, with the 12 forag es, the horses ingested 20.0 g DM/kg LW, against 18.5 g for the sheep (P = 0.06). The horses consumed more of the grass hays (+14%), less of the lucerne hays (-6.5%), and less straw (-5%). Voluntary dry matter intake in the two species was related to Crude Protein or Cell Wall Co ntent (NDF), but the relations were stronger in the sheep. The total t ime spent to ingest was 754 min in horses and 278 min in sheep, with 5 56 min of rumination in the latter, difference for total time spent ch ewing being significant. Number of meals was higher for horses: 11.9 a gainst 5.8, and the same for the length of each main meals: 168 min ag ainst 90. Time spent chewing was 84 min/kg DM in horses and 711 min/kg DM in sheep, giving 26.0 and 21.9 mg DM/min/kg LW, respectively. Inta ke in the horses was sustained throughout the day and nocturnal intake was noticeable (Fig. 2). Results are discussed taking into account tw o types of mechanism regulating intake in horses: a mechanism related to organoleptic characteristics of forages, probably bad for straws, a nd a mechanism related to relatively low rate of transit of the forage in the,out, even if this rate is higher than in sheep. (C) 1997 Elsev ier Science B.V.