|Wang, Zaisen - UNIV OF ARKANSAS|
|Conway, Michael - UNIV OF ARKANSAS|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 29, 1997
Publication Date: N/A
Interpretive Summary: A primary factor limiting the level of broiler litter in ruminant diets and production scenarios in which litter can be used is its low to moderate digestibility. A better understanding of factors responsible for variation among broiler litter sources in feed intake and digestibility and simple means to increase digestibility nutrient intake should increase the frequency and efficiency of use of broiler litter in ruminant diets. Results of this experiment indicate that when at a high dietary proportion, litter harvested after one broiler growing period elicits lower digestible energy intake by growing steers than litter obtained after at least three periods; whereas, the number of broiler growing periods may be of little or no practical importance to digestible energy intake with a lower dietary litter content and moderate grain level. Molasses addition to broiler litter before deep-stacking or at meals appears to offer no potential for improved feeding value of litter harvested after a large number of broiler growing periods (e.g., six). These results are of value to livestock and poultry producers to improve efficiency of utilization of the inexpensive and regionally abundant byproduct, broiler litter, as a feedstuff for ruminants. Decreased production costs that such research facilitates will enhance profitability of livestock and poultry production.
Technical Abstract: 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 were determined. In Exp. 1, eight steers (179+/- 7.4 average trial 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) was consumed ad libitum with offering of .5% BW of bermudagrass hay and .5 or 1.5% BW of ground corn (.5C and 1.5C, respectively); control steers ingested hay ad libitum with feeding of .5 or 1.5% BW (DM) of corn. 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 trial 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 (Control, LM, and HM, respectively). Molasses was mixed with litter at meals or before deep-stacking. Only a few minor treatment effects on intake and digestibilities occurred. In conclusion, DE intake by growing steers was less for litter harvested after one broiler growing period vs three or six when included in the diet at a high proportion, although impact of the number of periods was negligible with a moderate dietary litter level.