Intake and digestion by Holstein steers consuming different particle size fractions of broiler litter1

Eight Holstein steers (153±13.6 kg body weight) were used in two simultaneous 4×4 Latin squares with 21-day periods to determine effects of separating deep-stacked broiler litter into small and large particle size fractions on feed intake and digestibility. Steers were fed diets with or without two sources of deep-stacked broiler litter (source A: 24% crude protein and 35% neutral detergent fiber; source B: 23% crude protein and 44% neutral detergent fiber). All steers were fed ground corn at approximately 0.5% body weight (dry matter basis). Bermudagrass hay was consumed ad libitum by Control steers (without broiler litter) or at 0.5% body weight (dry matter basis) for treatments with dietary broiler litter. Broiler litter was consumed ad libitum without separation (whole; W) or after separation (1-mm screen aperture) into small (S; 27 and 33% crude protein for A and B, respectively) and large (L; 22 and 18% crude protein for A and B, respectively) particle size fractions. Organic matter intake was increased (P=0.06) by dietary inclusion of broiler litter (4.55, 4.56, 4.63, 4.73, 4.24, 5.18, 4.74 and 4.59 kg day−1 for Control-A, W-A, S-A, L-A, Control-B, W-B, S-B and L-B, respectively; SE 0.229). Total tract organic matter digestibility was greater (P=0.08) for broiler litter source A than for B (57.4, 57.8, 54.9, 57.6, 56.5, 48.4, 46.9 and 54.8%; SE 3.83), and digestible organic matter intake tended (P=0.11) to be greater for source A (2.56, 2.64, 2.54, 2.72, 2.36, 2.51, 2.16 and 2.58 kg day−1 for Control-A, W-A, S-A, L-A, Control-B, W-B, S-B and L-B, respectively; SE 0.166). In conclusion, separating deep-stacked broiler litter into two particle size fractions did not alter feeding value as assessed by digestible organic matter intake by growing steers.