Due to the increasing demand for alternative protein feed ingredients, the utilization of oilseed by-products in animal nutrition has been sought as a promising solution to ensure cheap and environmentally sustainable feedstuffs. This review aimed to summarize the nutritional value of six cold-pressed cakes (rapeseed, hempseed, linseed, sunflower seed, camelina seed, and pumpkin seed) and the effects of their inclusion in diet for ruminant, pig, and poultry on nutrient digestibility, growth and productive performance, and quality of the products. The presented results indicated that these unconventional feed ingredients are a good protein and lipid source and have a balanced amino acid and fatty acid profile. However, contradictory results of animal production performances can be found in the literature depending on the cake type and chemical composition, dietary inclusion level, animal category, and trial duration. Due to the substantial amount of essential fatty acid, these cakes can be efficiently used in the production of animal products rich in n-3 and n-6 polyunsaturated fatty acids. However, the utilization of cakes in pig and poultry nutrition is limited because of the presence of antinutritive factors that can deteriorate feed intake and nutrient utilization.

Selenium (Se) is an essential micronutrient that plays an important role in animal and human development and physiological homoeostasis. This review surveys the role of Se in the environment, plants and animal bodies, and discusses data on Se biofortification with different sources of supplementation, from inorganic to organic forms, with special focus on Se-enriched yeast (Se-yeast). Although Se-yeast remains one of the main sources of organic Se, other emerging and innovative sources are reviewed, such as Se-enriched insects and Se-nanoparticles and their potential use in animal nutrition. Se-enriched insects are discussed as an option for supplying Se in organic form to livestock diets. Se-nanoparticles are also discussed, as they represent a more biocompatible and less toxic source of inorganic Se for animal organisms, compared to selenite and selenate. We also provide up to date information on the legal framework in the EU, USA, and Canada of Se that is contained in feed additives. From the scientific evidence available in the literature, it can be concluded that among the inorganic forms, sodium selenite is still one of the main options, whereas Se-yeast remains the primary organic form. However, other potential sources such as Se-enriched insects and Se-nanoparticles are being investigated as they could potentially combine a high bioavailability and reduced Se emissions in the environment.

Former food products (FFPs) are foodstuffs that, even though they are nutritious and safe, have lost their value on the human consumption market for different reasons, such as production errors leading to broken or intermediate foodstuffs, surpluses caused by logistical challenges of daily delivery, or any other reason. The nutritional features of FFPs include carbohydrates, free sugars, and possibly also fats. FFPs tend to have been processed through various technological and heat treatments that impact the nutrients and the kinetics of digestion, as well as animal response and, particularly, gastro-intestinal health. This review integrates some of the most recently published works about the chemical composition, nutritional value, digestibility and glycaemic index of ex-foods. In addition, a view on the relationship between the use of FFPs and safety issues and their effects on pigs’ intestinal microbiota are also given.

The world’s population is growing rapidly, which means that the environmental impact of food production needs to be reduced and that food should be considered as something precious and not wasted. Moreover, an urgent challenge facing the planet is the competition between the food produced for humans and the feed for animals. There are various solutions such as the use of plant/vegetable by-products (PBPs) and former foodstuffs, which are the co/by-products of processing industries, or the food losses generated by the food production chain for human consumption. This paper reviews the by-co-products derived from the transformation of fresh-cut leafy salad crops. A preliminary nutritional evaluation of these materials is thus proposed. Based on their composition and nutritional features, in some cases similar to fresh forage and grasses, this biomass seems to be a suitable feedstuff for selected farm animals, such as ruminants. In conclusion, although the present data are not exhaustive and further studies are needed to weigh up the possible advantages and disadvantages of these materials, fresh-cut leafy salad crops represent a potential unconventional feed ingredient that could help in exploiting the circular economy in livestock production, thereby improving sustainability.

Growing population and rising incomes are leading to an ever-increasing demand for animal-based foods. Pigmeat is currently the most consumed meat globally, even exceeding the consumption of poultry meat. Despite the disproportionate environmental burden of animal production—mostly attributable to associated feed demand, up-to-date country-scale quantifications of the land and water impacts of the concentrate feed (mainly cereals and soybean) and co-products required to support pig production are still missing. In addition, the specific role that international feed trade plays in separating resource use from consumption and in altering resource use efficiencies remains unclear. This paper analyses at a country-scale the internal and external consumption of natural resources (i.e. land and water) to support pig feed production in 2018. Combining data on the country- and production system-specific diets and crop-specific yields with an agro-hydrological model, we find that 64.1 Mha of agricultural land (5% of all croplands) and 332.6 km³ of water (both green and blue) (6% of all agricultural water use) were utilized by China, EU-27 and the United States (accounting for 70% of pigmeat production) to produce pig feed alone. Comparing domestic feed production scenarios with those that also consider the feed trade, we show that global resource consumption tends to be more efficient when considering international feed trade, especially in China and EU-27, while sometimes causing significant environmental impacts. This demonstrates the need to investigate the environmental effects of pig feed associated both with the domestic use of natural resources, but also to the ones displaced by international trade.

The effect of a diet based on former food products (FFP) as alternative feed ingredients on in vitro and in vivo digestibility of dry matter (DM), pig growth performance, and selected plasma biochemical variables were evaluated. After an adaptation period (7 d), 12 post-weaning piglets (28 days-old) were housed for 16 d in individual pens and assigned to two experimental groups: Control (n = 6), received a standard diet and FFP (n = 6), received a diet in which conventional cereals (wheat, barley, and corn), plasma powder and whey powder, were partially replaced by 30% FFP. During the experiment, stool and blood samples were also collected for DM in vivo digestibility and for plasma biochemical measurements, respectively. The results revealed that both in vitro and in vivo digestibility values were higher (p<.05) for FFP diets compared to the control diets. At the end of the experiment, no differences in BW were observed between groups (p=.61). ADG and ADFI were not affected by dietary treatment. Conversely, piglets on the FFP diet showed a lower FCR (p<.01). Finally, dietary treatment also affected plasma glucose and urea, which in pigs fed FFPs increased and decreased, respectively. Taken together, these results suggest that the use of FFPs up to a level of 30% in post-weaning diets has no detrimental effects on pig growth performance, although more studies are needed to confirm these results.