Composition and storage stability of dry rendered spent hen meal

The spent hens were slaughtered by humane method and subjected to dry rendering process. The spent hen meal was packed in LDPE bags (250 gauge) and stored at ambient temperature (35±2°C) in cool dry place up to 90 days. The average yield of spent hen meal (SHM) and spent hen fat was 31.76% and 4.74%, respectively. During the dry rendering process the spent hen feathers were completely hydrolyzed and the colour of the spent hen meal was golden brown with pleasant meaty odour. The average values of moisture, crude protein, ether extract, crude fiber, total ash, calcium and phosphorus were 5.47, 72.12, 9.52, 0.23, 12.34, 4.38 and 2.15%, respectively. During storage TBA, tyrosine values, free fatty acid content and acid value and total bacterial counts increased significantly (P<0.01) and E. coli, Salmonella spp, Clostridium spp, Staphylococci spp, yeast and mould were absent. Even though odor scores decreased significantly (P<0.05) during storage, off or rancid odour was not detected during the storage. Retention of essential amino acids like lysine, methionine, cystine etc. in the spent hen meal also indicated that the biological value of the dry rendered spent hen meal was not affected during dry rendering. The results indicated that the spent hen meal could be safely stored up to 90 days at ambient temperature (35±2°C) in LDPE bags.