No abstract

Aflatoxins (AFs) remain the main concern for the agricultural and dairy industries due to their effects on the performances and quality of livestock production. Aflatoxins are always unavoidable and should be monitored. The objective of this paper is to bring to light a significant volume of data on AF contamination in several animal feed ingredients in Northern Italy. The Regional Breeders Association of Lombardy has been conducting a survey program to monitor mycotoxin contamination in animal feeds, and in this paper, we present data relating to AFB1 contamination. In most cases (95%), the concentrations were low enough to ensure compliance with the European Union’s (EU’s) maximum admitted levels for animal feed ingredients. However, the data show a high variability in AF contamination between different matrices and, within the same matrix, a high variability year over year. High levels of AFs were detected in maize and cotton, especially in the central part of the second decade of this century, i.e., 2015–2018, which has shown a higher risk of AF contamination in feed materials in Northern Italy. Variability due to climate change and the international commodity market affect future prospects to predict the presence of AFs. Supplier monitoring and control and reduced buying of contaminated raw materials, as well as performing analyses of each batch, help reduce AF spread.

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.

Magnesium (Mg) is a mineral that plays an essential role as cofactor of more than 300 enzymes. Mg in farm animals’ and human nutrition is recommended to avoid Mg deficiency, ensure adequate growth and health maintenance. Mg supplementation above the estimated minimum requirements is the best practice to improve farm animals’ performances (fertility and yield) and food products’ quality, since the performance of farm animals has grown in recent decades. Mg supplementation in pigs increases meat quality and sows’ fertility; in poultry, it helps to avoid deficiency-related health conditions and to improve meat quality and egg production by laying hens; in dairy cows, it serves to avoid grass tetany and milk fever, two conditions related to hypomagnesaemia, and to support their growth. Thus, Mg supplementation increases food products’ quality and prevents Mg deficiency in farm animals, ensuring an adequate Mg content in animal-source food. These latter are excellent Mg sources in human diets. Sub-optimal Mg intake by humans has several implications in bone development, muscle function, and health maintenance. This review summarizes the main knowledge about Mg in farm animals and in human nutrition.

Selenium (Se) is an essential trace element for livestock. The element can be supplemented to feed in inorganic or organic Se forms, where the chemical form in the diet affects the accumulation of Se in animal tissues. Insects are known to be natural bioaccumulators of different nutrients, but no studies have so far looked up on the capacity of insects to be biofortified with Se, as a potential future source for Se in feed. In this study, black soldier fly (BSF, Hermetia illucens) larvae were reared on three different substrates: (1) a control substrate (CTR diet) of plant-ingredients (Gainesville diet); (2) Ascophyllum nodosum diet (AN30%), with 30% substitution of the alfalfa meal with the brown algae; and (3) a Se diet, where the CTR diet was fortified with 0.3 mg/kg of Se. All experiments were carried out under dark condition, at 25 °C with 70% relative humidity for two weeks, and the final BSF prepupae were analysed for Se, metals and minerals, and Se species. The mean total Se content in the prepupae reared on Se dietary group was over five times higher compared to the CTR group, whereas lower Se levels were detected in AN30% dietary group. Se speciation analyses showed that organic selenomethionine (SeMet) was the major Se species present, both in CTR and AN30% group. For the Se group, SeMet was accounting for 54% of the total Se. The levels of SeMet were higher in the Se group compared to the CTR group, indicating that BSF prepupae are able to convert inorganic Se to organic Se. The overall results show that the substrates hereby studied affect the total Se and Se species, as well as the levels of other elements, in the BSF prepupae.