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Chickpea grains may represent an alternative to soybean meals and energetic concentrates in animal feeding, as their nutritional value can help to increase the sustainability of livestock systems. Unfortunately, the presence of bioactive compounds with anti-nutritional effects can prevent its direct use, especially in mono-gastrics. It is known that the synthesis of these compounds depends on genetic expression, which is also influenced by growth conditions. The objective of this two-year study was to assess the effect of sowing date (winter versus spring) and seeding rate (70 versus 110 seeds m&minus, 2) on the accumulation of soluble carbohydrates, &alpha, galactosides, trypsin inhibitors, and inositol phosphates in the grains of two Kabuli cultivars, in the Mediterranean climate. The results showed that seeds collected from winter sowing contained more trypsin inhibitors than those seeded in spring (+ 4%, on average), reaching values between 16.1 and 18.6 TIU mg protein&minus, 1. The seeding rate affects only the &alpha, galactosides content, which increases (+9%) at lower densities (70 seeds m&minus, 2). These findings suggest that agronomic management can be used to modulate the content of some anti-nutritional factors in the seeds, even though the genetic characteristics and phenotypic expression, in relation to the climatic conditions, seem to deeply affect the content of all the bioactive compounds investigated.

The black soldier fly (BSF, Hermetia illucens L.) is a very promising insect species due to the ability to convert low-value substrates in highly nutrient feed. This work aimed to study the effect of three nominally isoenergetic diets containing plant ingredients such as barley, alfalfa, and wheat byproducts, formulated to be higher in nonfiber carbohydrates (TMD1), fibers (TMD2), and protein (TMD3) in comparison to an extensively genetic modified cereal (cornmeal)-based diet (C), on the growth, yield, and nutritive traits of BSF prepupae (BSFPs). Three growing trials with four biological replicates were carried out. Proximate and fatty acid analyses were performed on the diets and BSFPs. Feed conversion ratios (FCR), dry matter and nutrient yields, and apparent concentration factors (aBCF) for fatty acids (FAs) were calculated. Diet formulation had a substantial effect on the survival, development rate, and larval yield, but the FCR was unaffected. The BSFPs fed TMD3 did not result in a higher crude protein content in comparison to the C or TMD2 diets. Despite the leveled fat content of the diets, BSFPs reared on TMD1 were highest in fat, saturated FA, and fat yield. An apparent bioconcentration factor (aBCF) value lower than unity that was found for the unsaturated FA suggests that the BSFPs inefficiently absorb them from the diet or possibly turn them into saturated FA. However, the unsaturated FA accumulation in BSFPs depended on the levels that were found in the diet, which suggested some possibilities for the FA profile modulation. Overall, the TMD2 performed well despite the low-value of its main ingredients and high fiber content and can be considered to be a feasible option for the mass rearing of BSFPs that are intended for animal feed.

In formulating diets for farmed aquatic species, the main ingredi- ent used is fish meal (FM). Due to the growth that aquaculture is experiencing throughout the world, the increasing demand of feeds is resulting in a FM price increase that represents an eco- nomic limit for fish farming. The need to seek protein sources alternative to FM is a matter of great interest. Among others, the use of insect larvae as feed for fish represents an interesting alter- native. The aim of this study was to evaluate the nutritional traits of mediterranean brocade larvae (Spodoptera littoralis Bois.) in view of their possible use as feedstuffs for rainbow trout. A sample of mediterranean brocade larvae (MBL) (VI instar) and one of pupae (MBP) were assayed for fat (EE), ash (ASH) and crude pro- tein (CP) contents by conventional methods. Amino-acidic profile was obtained by HPLC on sample hydrolysates. Relative digestibil- ity of protein (RDP) was estimated by the Lazo (1988) method. Data, expressed on DM basis, were compared with those of a com- mercial feed (CF). The fat content of MBL was lower than that recorded for CF (9.4% vs 13.6%) while MBP showed a very high value (30.3% DM). Ashes in MBL (7.7%) and MBP (6.7%) were lower than in the CF (10.9%). The CP content of MBL (44.3%) was slightly higher than the CF (40.0%) but lower than in MBP (59.1%). The RDP of MBL and MBP were about a half of the value observed in CF (27.2%). Both MBL and MBP showed a lower per- centage of essential amino acids (AA) (35.8%, 36.8%) compared to CF (39.4%) even if the AA profiles were in line with the require- ments found in literature for rainbow trout. In conclusion, these preliminary results suggest that preimaginal stages of S. littoralis may be of interest in fish feeding, though more exhaustive studies have to be performed to fully assess their use as alternative for fish meal.

The expected future demand for highly nutrient animal food products will push the animal production system to search for new sources of high-quality protein feedstuffs. In this scenario, economic and environmental issues will have to be considered while reducing the competition with the plant-based human food chains. Legume grains and some oilseed cakes, by-products from the oil industry, are the main protein sources for ruminants and terrestrial monogastrics such as pigs and poultry. Their relevant role will hold in the next decades, but it is necessary to increase the diversification of sources that can be grown profitably throughout the world, including European countries. Microalgae are a promising source of protein and other nutrients for animal feeding. However, an amazing richness of biologically active substances makes these organisms very interesting as feed ingredients, as their role go far beyond the supply of nutrients. Due to the limited usage of microalgae as human foodstuffs or food ingredients, low competition between microalgae-based feed and food chains is predictable. This review aims to synthesise current knowledge on minor pulses and other protein-rich plant products and microalgae, as alternative ingredients to the conventional animal protein sources, focussing on their production, availability, and nutritional values. Points of strength, weakness, opportunity and threat related to the use of these protein sources in animal feeding are separately analysed through a SWOT approach to underlie future needs in terms of research and/or technological development that could help valorise these nutrient sources as feed ingredients.