EFFECT OF PARTICLE SIZE ON, INTAKE, DIGESTIBILITY AND NITROGEN BALANCE IN PELIBUEY SHEEP FED DIETS BASED ON VELVET BEAN (Mucuna pruriens) AND CORN GRAIN

Abstract

The objective was to measure the effect of particle size on intake, apparent digestibility, digestive kinetics and N balance in Pelibuey sheep. Three particle sizes were tested: Small (S), Medium (M) and Large (L) which were obtained by grinding through mesh sizes of 3, 13 and 25 mm respectively. Twelve hair sheep (20 ±3.3 kg LW) were allotted to a completely randomized design. DM intake was similar (P>0.05) among treatments (101 g/kgLW0.75/d). Total chewing time (intake + rumination) was unaffected by diet particle size (P>0.05), although a trend was observed towards an increase (P= 0.0522) as particle size was augmented (408, 532, 562 min/d for S, M and L respectively). DM digestibility was greater (P<0.05) for M with respect to Small (782 and 734 g/kg DM). Mean retention time in the total tract was different (P<0.05) between particles size (20.1 and 35.5 h for S and L). N retention was not affected by diet particle size (17.9 g N/d). Microbial N supply to the small intestine was similar between treatments (5.7 g/d). It is concluded that feeding systems of sheep could employ a larger particle size than that conventional utilized (S) in commercial feedstuffs.