Improving sustainability of poultry production by feeding insects: state of the art and perspectives

The market for poultry products (egg and meat) is growing worldwide owing also to the absence of cultural or religious obstacles. Dietary protein sources represent the primary production costs. Soybean meal is the most used protein source in the diet formulations for broilers and laying hens. However due to its ever-increasing price, the sustainability of this production chain is becoming critical, in particular in some developing countries. Therefore, alternative feed protein sources, locally available and sustainable are required. The use of insects as an alternative source of protein in animal feeding is becoming globally more appealing, especially for its sustainability. In addition, insects (adult, larval and pupal form) are consumed naturally by wild birds and free-range poultry. The rural poultry farming in the economy and food security of developing countries has been momentous. Studies have shown the feasibility of using insects as an alternative feed source or as complementary feed source for poultry. Grasshoppers, darkling beetle, crickets, cockroaches, termites, lice, stink bugs, cicadas, aphids, scale insects, psyllids, beetles, caterpillars, flies, fleas, bees, wasps and ants have all been used as complementary food sources for poultry. Soybean or fish meal in broiler chicken or laying hen diets have been successfully replaced at low inclusion levels by black soldier flies (Hermetia illucens), housefly (Musca domestica), mealworms (Tenebrio molitor) and silkworm (Bombix mori) pupae. Insect inclusion in poultry diets ranged between 0.2 to 20 % without affecting growth performance or, in some cases, by improving it. An obstacle to the use of insect meals in poultry diets is the lack of information about nutrient digestibility in commercial poultry farms. Recently, Schiavone et al. (2015), have estimated the nutrient and apparent metabolizable energy values for mealworms and black soldier flies pupae used in chickens feeding. The use of insects as sustainable protein-rich feed ingredient in poultry diets is technically feasible. Insects can be reared on low-grade bio-waste substrates transforming them into high-quality proteins. Furthermore, invertebrates are a raw material included in the Feed Register Material of the EU. Although they are currently authorized only for pet feeding, insect-derived feed could represent in the near future a suitable ingredient for poultry, too.