Compared feeding patterns in ad libitum intake of dry forages by horses and sheep

Abstract

Two trials were performed to compare voluntary dry matter intake and feeding behaviour in adult gelding saddle horses, weighing 500 kg, and adult sheep, weighing 70 kg. In each trial, 4 grass hays, 1 lucerne hay and 1 straw were given to the animals. On average, with the 12 forages, 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 Content (NDF), but the relations were stronger in the sheep. The total time spent to ingest was 754 min in horses and 278 min in sheep, with 556 min of rumination in the latter, difference for total time spent chewing being significant. Number of meals was higher for horses: 11.9 against 5.8, and the same for the length of each main meals: 168 min against 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. Intake in the horses was sustained throughout the day and nocturnal intake was noticeable (Fig. 2). Results are discussed taking into account two types of mechanism regulating intake in horses: a mechanism related to organoleptic characteristics of forages, probably bad for straws, and a mechanism related to relatively low rate of transit of the forage in the gut, even if this rate is higher than in sheep.