Preservation and nutritional value of caged layer waste treated with different preservatives
Two experiments were conducted with caged layer waste. In the first experiment fresh waste was treated with: no additive, 2% formaldehyde, 3% sodium metabisulfite, 1% formaldehyde and 2% propionic acid, 3% formic and 2% propionic acids and stored in polyethylene lined 208 liter metal drums. In experiment II waste treated with 2% formaldehyde, 1 % formaldehyde and 2% prop ionic, 3 % formic and 2% propionic (w/w), stored for at least 42 d, used in a metabolism trial as N supplements to a basal diet fed to sheep.
The formaldehyde, formaldehyde/propionic and formic/propionic treatments eliminated the bacterial decomposition of the waste and no undesirable fermentation was observed on the stored material. Waste treated with no additive or sodium metabisulfite underwent putrefaction.
Nitrogen supplementation of a basal diet with treated caged layer wastes improved apparent digestibility of crude protein and N retention in sheep fed these diets.
Supplementation of a basal diet with chemically treated caged layer waste improves the nutritional value of the diet which suggests that caged layer waste is efficiently utilized as a N source by ruminants when used as a protein supplement.