Supplemented feed with biological silage of fish-processing wastes improved health parameters and weight gain of mice

Wastes from Merluccius hubbsi processing were used for biological silage elaborated with Lactobacillus arizonensis and for chemical silage performed with 0.18M sulfuric acid and 0.22M formic acid. Mice BALB/c were fed with isoenergetic diets, EFBS and EFCS, containing 36.3% (wt/wt) biological fish silage and 36.3% (wt/wt) chemical fish silage respectively. Promisingly, after 30 day consumption both additives did not provoke lesions in the gut, thinner wall, distension or abnormal vascularization. The higher concentration of lactic acid bacteria (LAB) in the gut of mice fed with EFBS (2.51 × 104 cfu LAB/g EFBS vs. 3.98 × 103 cfu LAB/g EFCS), together with the weight gain (23.8 ± 3.8 g vs. 16.7 ± 3.7 g), feed conversion ratio (4.12 vs. 6.71), protein efficiency rate (0.69 vs. 0.63), villi height (455 μm vs. 418 μm) for EFBS and EFCS respectively, support the probiotic effect of L. arizonensis. Nevertheless, both preparations are interesting options to envisage a promising outcome for recycling fish wastes.