Abstract
Fish waste was preserved using sugar cane final molasses with and without lactic acid bacteria (LAB) to produce a fermented fish waste silage and used to assess the nutritional and microbial characteristics of the product. One set of batches of chopped fish waste (comprising offals and by-catch) was mixed with 50, 150, 250, and 500 g kg-1 molasses without inoculant. The other set was treated with 50, 150, and 250 g kg-1 of molasses with an inoculant. The inoculant with LAB (Streptococcus fasecium, Lactobacillus plantarum, and L. acidophilus) 2.5 x 106 colony forming units mL-1 was added at 25 mL kg-1. Each treatment had four replicates in a completely randomized design. After the first 24 h of fermentation, the pH ranged from 4.35 to 4.69 among treatments (P > 0.05) with the exception of the 500 g kg-1 molasses treatment which had a higher pH value (5.14; P < 0.05). Silage mixtures containing 50 g kg-1 sugar cane final molasses with and without inoculant resulted in putrefaction, increased pH levels (7.17-7.37), and eradication of Lactobacilli, organisms. At 504 h, the pH ranged from 3.99-4.44 for treatments with 150-500 g kg-1 molasses inclusion level, with or without inoculant. The values for crude protein, ether extract, and ash for the five silages ranged from 270.0 to 558.0, 72.5 to 141.0, and 134.6 to 167.6 g kg-1 dry matter (DM), respectively. Similarly, mineral content for Ca, P, and S ranged from 40.3 to 59.5, 11.0 to 32.0, and 5.4 to 10.8 g kg-1 DM, respectively. It was concluded that fish waste could be ensiled with sugar cane final molasses at 150-500 g kg-1 inclusion levels with and without an inoculant. Chemical composition values indicated that the final product had a high nutritive value as a protein source for ruminants and non-ruminant feeding.
