Intake and digestion by Holstein steers consuming diets based on litter harvested after different numbers of broiler growing periods or with molasses addition before deep-stacking.

We determined the effects on feed intake and digestibility by Holstein steers of 1) the number of broiler growing periods before litter harvest and dietary level of broiler litter and 2) level of molasses added to broiler litter before deep-stacking. In Exp. 1, eight steers (179+/-7.4 kg average BW) were used in two simultaneous 4 x 4 Latin squares (2 x 4 factorial) with 21-d periods. Broiler litter harvested after one, three, or six 6-wk growing periods (1P, 3P, and 6P, respectively) mixed with .5 or 1.5% BW of ground corn (.5C and 1.5C, respectively) was consumed ad libitum. Bermudagrass hay was fed to 1P, 3P, and 6P steers at .5% BW and was ingested ad libitum by Control steers, along with feeding of .5 or 1.5% BW of corn (DM basis). Broiler litter was 63, 43, and 35% NDF, 2.2, 3.5, and 4.1% N, and 18, 30, and 27% ash for 1P, 3P, and 6P, respectively. Total tract digestibility of NDF was 53.7, 29.4, 50.4, 58.1, 31.3, 30.8, 34.1, and 49.5% (SE 3.50), and digestible OM intake was 2.21, 1.70, 2.27, 2.39, 2.26, 3.18, 2.93, and 3.34 kg/d (SE .160) for .5C-Control, .5C-1P, .5C-3P, .5C-6P, 1.5C-Control, 1.5C-1P, 1.5C-3P, and 1.5C-6P, respectively. In Exp. 2, five steers (228+/-6.0 kg average BW) were used in a 5 x 5 Latin square with 21-d periods. Offered diets were 15% bermudagrass hay and 60% broiler litter (6P of Exp. 1; DM). Molasses was offered at 0, 3.2, or 6.7% of total DM, with the balance of the diet composed of corn. Molasses for two treatments was mixed with litter at meals, whereas for two other treatments molasses and litter were mixed before deep-stacking. Only a few minor treatment effects on intakes and digestibilities occurred. In conclusion, digestible OM intake by growing steers was less for litter harvested after one broiler growing period than after three or six when fed with only .5% BW of corn, although the effect of the number of periods was negligible with corn given at 1.5% BW. Molasses addition before deep-stacking or at meals did not enhance feeding value of litter harvested after six broiler growing periods.