Protein rich ingredients from fish waste for sheep feeding

Abstract

Fish wastes, including viscera, heads, tails and skins, were ground and mixed with 10% molasses and inoculated with a starter culture made of Lactobacillus plantarum. The inoculated mixture was incubated at 25°C for 10 days, for a biopreservation/biotransformation by fermentation. During the fermentation period, changes in nutritional quality and biochemical properties (pH, dry matter, ash, total and volatile nitrogen and lipids) were monitored as well as microbiological determinations, including standard plate count, coliforms and Clostridium. Results indicated that the ph decreased considerably and remained constant at 3.8 after 8 days. Total nitrogen, decreased non protein nitrogen and total volatile nitrogen increased. The microbiological characteristics showed a drastic decrease of coliforms and Clostridium counts in 8 days. Two trials and a control were carried out and the final fish waste silage product was used in feeding sheep in two trials of 5 sheep each. The fish silage was added to ground barley and wheat bran* in two proportions respectively (40% barley, 25% fish silage and 35% wheat bran) and (40% barley, 50% fish silage and 10 % wheat bran). The control diet was the conventional feed adopted in the region (40% barley, 60% wheat bran*). The weight gain was followed up for 9 weeks. The results indicated that trial feeding studies with young sheep using formulas containing fish silage showed a net increase in weight above controls as well as a good enhancement of meat characteristics and carcass shape. Keys words: Fish wastes, molasses, barley, wheat bran, Lactobacillus plantarum, fish silage, sheep feeding.