The effect of defatted Hermetia illucens meal (HIM) dietary inclusion on growth performance, stress indicators and gut histological traits of Sparus aurata was studied. For 131 days, 312 fish were fed with one basal diet, containing fish meal as animal protein source, and three diets containing 25%, 35% and 50% HIM as a partial replacement for fishmeal. On all fish (26 fish per tank, 3 replicate tanks per diet, 78 fish per diet) the growth performance were calculated. At the end of the trial, on a subsample of 72 specimens (6 fish per tank, 3 replicate tanks per diet, 18 fish per diet), stress parameters were determined on blood samples and gut histological tract investigated. Insect meal inclusion did not affect (p > 0.05) growth performance, blood parameters, length and width of villi and goblet cell count of the posterior gut tract while, those of the anterior gut tract while increased (p < 0.05). The histological examination of the intestinal sections showed in fish fed the HIM25 and HIM50 diets, more frequent and evident morphological changes; instead, there were no substantial differences between HIM0 and HIM35 groups. In conclusion, the HIM35 was the most tolerated formulation by fish.

Two extruded diets isoenergetic, isonitrogenous, and isolipidic were formulated with poultry meal (CTR) as the source of animal-origin proteins (160 g/kg of feed) or with 90 g/kg of poultry meal and 70 g/kg of HFM (TRT) and were fed to eight dogs (four adult female and four adult male English Setters). Over 45 days, body weight, body condition, muscle condition, and fecal consistency scores were monitored at the beginning of the trial and after 3, 7, 15, and 45 days. No significant differences (P > 0.05) were observed for these parameters between diets and between sex. Fecal samples, collected at the same time points, were analyzed for microbiota composition. There was no significant difference in Shannon alpha diversity between the control (CTR) and experimental (TRT) diets or for diet × sampling time interaction and sex. However, beta diversity differed between diets (PERMANOVA p=0.001) and for diet × sampling interaction (p=0.009), with specific significant time points, and also differed by sex (p=0.047). LEfSe analysis showed Clostridiales, Coprococcus, Bacteroides plebeius, and others were more abundant in CTR, while Fusobacterium, Enterobacteriaceae, and others were more abundant in TRT. Temporal shifts in taxa like Prevotella copri and Fusobacterium were observed, with 25 taxa differing by sex. The study highlights diet and sex effects on gut microbiota in dogs.

Hemp (Cannabis sativa L.) is an annual plant belonging to the family of Cannabaceae with several varieties characterised by different fatty acid profiles, content in flavonoids, polyphenols and cannabinoid compounds. Hemp is mostly used in livestock nutrition as oil or as protein cake, not as inflorescences. The aim of this study was to evaluate the effect of dietary hemp inflorescences on milk yield and composition in grazing goats. Twenty goats (Camosciata delle Alpi), after kidding, were equally divided into two groups (G: Grazing and GH: grazing and hemp), homogeneous for milk yield in the previous lactation, parity and live weight. For three months, all goats were fed on a permanent pasture and received 700/head/day of concentrate (barley, oats and faba bean); diet of group GH was supplemented with 20 g/head/day of hemp inflorescences. Pasture DM intake was estimated according to previous research performed in the same area. In addition, goats’ body weight did not change along the trial meaning that their energy requirements were guaranteed. Individual milk yield was daily registered and samples collected every 20 days for chemical com-position (Milkoscan) and fatty acid profile (Gas Chromatography). The data were analysed by ANOVA (GLM procedure of SAS, 2000), for repeated measure. No significant differences were found for milk yield and chemical composition. Lauric acid (C12:0) was significantly higher in milk of group GH (4.83% vs 4.32%; P<0.01) as well as total conjugated linoleic acids (CLAs) (0.435% vs 0.417%; P<0.01).

This study addresses the urgent need for sustainable protein sources in aquaculture due to the depletion of marine resources and rising costs. Animal protein sources, particularly poultry by-product meal (PBM) and insect exuviae meal, are investigated as viable alternatives to fishmeal (FM). Research confirms the successful replacement of FM with a combination of PBM and insect exuviae meal (up to 50%) in the diet of European seabass without compromising growth, feed conversion, gut health and liver fat content. In particular, growth performance was robust with both PBM formulations, with the 25% PBM diet showing better results. Histological examinations showed good gut and liver health, contradicting the concerns of previous studies. The study emphasizes the importance of holistic analyzes that go beyond growth parameters and include histomorphological investigations. The results show that PBM in combination with insect/exuviae meal is well tolerated by seabass, which is consistent with literature reports of mitigating negative effects on gut health. A detailed analysis of the microbiota revealed a decrease in the Firmicutes/Proteobacteria ratio due to an increase in potentially pathogenic bacteria. However, the formulation containing insect exuviae partially counteracted this effect by preserving the beneficial Lactobacillus and promoting the synthesis of short-chain fatty acids (SCFA), particularly butyrate. Chitin-rich components from insect exuviae were associated with improved gut health, which was supported by increased production of SCFA, which are known for their anti-inflammatory properties. The study concludes that a combination of PBM and insect/exuviae meal can replace up to 50% of FM in the diet of seabass, supporting sustainable aquaculture practices. Despite some changes in the microbiota, the negative effects are mitigated by the addition of insect exuviae, highlighting their potential as a prebiotic to increase fish productivity and contribute to a circular economy in aquaculture.