|Wang, Z - UNIV OF ARKANSAS|
|Patil, A - UNIV OF ARKANSAS|
|Rossi, J - UNIV OF ARKANSAS|
|Kouakou, B - UNIV OF ARKANSAS|
|Park, K - UNIV OF ARKANSAS|
|Galloway, D - UNIV OF ARKANSAS|
Submitted to: Journal of Applied Animal Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 16, 1997
Publication Date: N/A
Interpretive Summary: Broiler litter is an abundant agricultural byproduct for which disposal has been problematic. Improper land application can contribute to groundwater contamination. Alternatively, broiler litter can be used as a feedstuff for cattle with much greater realized value. However, a nutritional characteristic of broiler litter than limits levels in ruminant tdiets and production scenarios in which the byproduct feedstuff can be effectively used is a low available energy concentration. In this experiment, addition of bermudagrass hay to broiler litter before deep- stacking did not alter nutritive value differently than expected based on initial chemical composition. Molasses decreased fiber recovery slightly but did not affect neutral detergent soluble organic matter recovery or substantially or consistently increase in situ ruminal dry matter disappearance. Changes occurring with urea inclusion imply increased ruminally fermentable organic matter available for support of ruminal microbial growth that should elevate ruminal capture of nitrogen. However, with increased substrate nitrogen concentration it is doubtful that the proportion of ingested nitrogen captured in microbial protein would be increased by urea. These results have importance to cattle producers and feed manufacturers. For example, a much greater improvement in nutritive value of broiler litter by addition of molasses before deep- stacking was noted in previous research compared with this experiment. Thus, this research suggests that further experimentation is necessary to understand factors responsible for such differences before this technology can be applied in the field.
Technical Abstract: Broiler litter was deep-stacked with bermudagrass hay or molasses added singly at 0, 5, 10 or 20% (dry matter; DM) or in 1:1 (DM) mixtures at 0, 10 or 20% (DM). Urea was included at 0, 2.8 or 5.6% (DM), and substrates were placed in dacron bags in the center of deep-stacks of broiler litter with the same levels of urea either covered with plastic or open. Recovery of neutral detergent fiber (NDF; ash-free) was decreased more (interaction; P<0.05) by urea with open than with covered litter and was less (P<0.05) for 5.6 vs 2.8% urea (67, 58 and 54% with open litter and 75, 60 and 56% with covered litter for 0, 2.8 and 5.6% urea, respectively; SE 1.2). Molasses addition decreased (P<0.05) and inclusion of 10 or 20% bermudagrass increased (P<0.05) NDF recovery (62, 56, 56 and 55% with molasses and 62, 62, 68 and 73% with bermudagrass at 0, 5, 10 and 20%, respectively; SE 1.4). Recovery of neutral detergent soluble organic matter (NDSOM) was not affected (P<0.05) by treatments with covered litter, and with open litter NDSOM recovery was similar between bermudagrass and molasses substrates. Overall, increases in 12-h in situ ruminal DM disappearance due to urea inclusion coincided with changes in concentrations and recoveries of NDF and NDSOM regardless of air exposure treatment and carbonaceous feedstuff source and level, and treatments other than urea had relatively small effects. Treatment effects on 48-h DM disappearance were small in magnitude. Mixtures of bermudagrass and molasses added to broiler litter resulted in effects expected based on additive effects of singular additions. In conclusion, only urea improved nutritive value as assessed by chemical analyses and in situ digestion, although changes appeared restricted to fiber solubilization.