Effects of Dietary Fishmeal Replacement by Poultry By-Product Meal and Hydrolyzed Feather Meal on Liver and Intestinal Histomorphology and on Intestinal Microbiota of Gilthead Seabream (Sparus aurata)

The effects on liver and intestinal histomorphology microbiota in gilthead seabream (Sparus aurata) fed diets that contained poultry by-product meal (PBM) hydrolyzed feather (HFM) as fishmeal replacements were studied. Fish a series of isonitrogenous isoenergetic diets, where protein the control diet (FM diet) was replaced by either PBM or HFM at 25%, 50% 100% without amino acid supplementation (PBM25, PBM50, PBM100, HFM25, HFM50 HFM100 diets) supplemented with lysine methionine (PBM25+, PBM50+, HFM25+ HFM50+ diets). use 25% replacement generated similar hepatic to FM-fed fish, indicating both land animal proteins are highly digestible low FM levels. However, levels resulted pronounced alterations fish latter causing more severe degradation liver. Dietary delivered an improved tissue histology signifying their importance high Intestinal dominated Proteobacteria (58.8%) Actinobacteria (32.4%) all dietary groups, but no specific pattern observed among them any taxonomic level. This finding probably driven inter-individual variability observed.