INSETTI E PRODOTTI DERIVATI COME INGREDIENTI ALIMENTARI PER AVICOLI E CUNICOLI

Due to the constant increase in the World population, the demand of animal-based products is expected to raise by 35%, 52%, 40% and 39% within 2050 for fish, meat, milk and eggs, respectively. This increase is putting pressure on the already overexploited natural resources, as livestock production requires large amounts of feed, land, water, etc. In this perspective, it is evident that the search of alternative and sustainable feed resources for the livestock sector is of great interest. Among the possible alternative feed (and food) sources for the near future, insects are seen as one of the promising options to improve the global feed and food security. In fact, insects are characterised by a high nutritional quality, they have a high reproductive capacity, and then need limited amounts of land and water to grow. Furthermore, insects can be reared on different bio-waste streams, thus becoming natural tools to recycle waste into valuable feed (and food) sources. For the above-mentioned considerations, the present thesis aimed to study the nutritional value of selected insect species and their possible inclusion in poultry and rabbits’ diets as a replacement of conventional feedstuffs. The 1st research tested the effect of seven different killing methods (blanching, steaming freezing, CO2, vacuum, plastic bag, and CO2 + blanching) on various quality attributes of the house cricket meal physicochemical traits, and oxidative stability of the product during storage. Results of this research highlighted that none of the tested killing methods had a negative impact on product quality, thus indicating that the choice of the most appropriate killing strategy seems to be a matter of equipment availability and cost-efficiency ratio. The 2nd research of the present thesis evaluated the dietary inclusion with partly defatted black soldier fly larvae meal (BSF: 10% or 15%) as an alternative feed source in the diets of laying quails on productive performance, morbidity and mortality, egg physical and chemical traits, fatty acid profile, sensory and storage stability. Based on the obtained results, BSF could be considered as a possible alternative ingredient for laying quails’ diets up to the 15% inclusion level. The 3rd research of the present study evaluated the effect of the dietary inclusion (12.5%) of a full-fat or a defatted silkworm pupae (SW) meal in the diet for meat-producing quails on the apparent digestibility of nutrients, nutritive value of diets, feed-choice and faecal microbiome. Overall, findings indicated that the 12% SW meal inclusion dietary negatively impacted nutrients digestibility of growing quails as well as their feed-choice, mainly due to the presence of bioactive compounds. Such negative impact on nutrients absorption and thus digestibility was highlighted also by the analysis of faecal microbiome. The 4th research of the present thesis evaluated the dietary replacement of 25% and 50% soybean meal with full-fat SW meal in chickens. Results of the study showed that both replacement levels ensured optimal growth performance, carcass and meat quality traits. Moreover, the n-3 FA proportion and n-6/n-3 ratio of SW meal-fed chickens improved compared to the control group, thus demonstrating that full-fat SW meal is a rich source n-3 FA that can improve product healthiness. The 5th research, which was also the last study of the present thesis, tested the complete replacement of sunflower oil with silkworm pupae oil (SWO: 1.3%) in the diet for growing rabbits. For this experiment, the impact of the experimental diets was assessed on total tract apparent digestibility of nutrients and nutritive value of diets, as well as meat physicochemical traits, sensory profile and shelf-life. Results indicated that SWO can effectively replace sunflower oil into rabbit diets without any detrimental effect on all the considered traits, including oxidative stability during retail display.