The present studywas carried out to evaluate the in situ degradation of dry matter (DM),neutral detergent fiber (NDF) and crude protein (CP) in roughages by the insitu caecal digestion technique in horses. The roughages evaluated were:Lucerne hay (Medicago sativa), peanut (Arachis pintoi cv. Amarillo),desmodio(Desmodium ovalifolium), stylo (Stylosanthes guianensiscv. Mineirão), pigeon pea (Cajanus cajan), lime-yellow pea (Macrotylomaaxillare) and coastcross hay (Cynodon dactylon cv. coastcross). Theassay was conducted in a complete randomized design with seven roughages andthree replications. One mare with a cannula fitted in the caecum wasused, fed diet consisting of coastcross hay (80%) and concentrate (20%) at 2.0%BW, four times a day. Nylon 6.5 × 20 cm bags were used with 45 μ/pore,containing 5.2 g DM/bag, inserting 3 or 4 bags in the caecum at the times of2, 4, 6, 8, 12, 24 and 48 hours incubation. The caecum in situ degradabilityparameters of nutrients were obtained by Ørskov model. The DM degradabilityparameters of all the roughages were significant. There was no fit to the modelfor pigeon pea for CP and NDF and desmodio. Peanut, stylo and lime-yellow peapresented larger potentially degradable DM with values of 53, 46.5 and 40%,respectively, and higher values for the soluble fraction of 20, 21, 28.6%, withhigh degradability rates of 10.36, 20.26 and 14.8% h-1. Higher NDFdegradation rates were observed in these foodstuffs with values of 9.1 and 11.3,11.2% h-1, high potentially degradable fraction with values of 55,51.8 and 47.2%, and greater CP degradation at 48 hours with values of 87, 95,and 94.8%. Peanut, stylo and lime-yellow pea presented potential for use inhorses diets.
