Ecological desalination of anchovy bones using lime and activated carbon made from argan shells: sustainable use of waste for poultry feed in Morocco

Abstract

This study aims to develop an environmentally friendly process for desalinating salted anchovy bones (Engraulis encrasicolus) through the combined use of activated carbon from argan tree shells (Argania spinosa) and quicklime (CaO), with a view to sustainable recovery for poultry feed. The bones, which are rich in protein and minerals but highly salty, were successively treated with water, activated carbon (0.25–0.5 g/5 g of bones), and then quicklime (0.5–1.5 g/5 g of bones). Physicochemical analyses revealed a significant reduction in salt content, from 15.4% to less than 0.6%, accompanied by a marked increase in calcium (up to 10.74%) and magnesium (1.32%), while maintaining stable levels of crude protein (≈29%) and fat (≈5.7%). The fish bone meal obtained in this way was incorporated at a rate of 3% into feed formulations for broiler chickens (Gallus gallus) during the starter and grower phases, using ALLIX³ software. Zootechnical trials showed no negative effects on live weight, feed intake, or feed conversion ratio compared to the control group, confirming the equivalent nutritional value of the experimental diets. This integrated approach simultaneously valorizes fishery and agricultural co-products, contributing to the implementation of a circular economy model and the achievement of Sustainable Development Goals (SDGs 12 and 14).