Sugary and salty former food products in pig diets affect energy and nutrient digestibility, feeding behaviour but not the growth performance and carcass composition.

Former foodstuff products (FFPs) are promising alternative ingredients for reducing the waste of natural resources and the environmental impact of food production. This study investigates the effects of salty and sugary FFPs on growth performance, apparent total tract digestibility (ATTD), and growing-finishing pigs' empty body and carcass composition. Thirty-six Swiss Large White male castrated pigs were assigned to three growing (G) and finishing (F) diets: (1) standard diet (ST), 0% FFPs; (2) 30% conventional ingredients replaced by sugary FFPs (SU); and (3) 30% conventional ingredients replaced by salty FFPs (SA). Faecal samples from 24 selected pigs were collected to assess the ATTD of gross energy, crude fibres, and CP. The BW was measured weekly, while feed intake was determined daily. Average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR), and ATTD were calculated for both the growing and finishing periods. Pigs' body composition was determined at ≥20 and ≥98 kg using dual-energy X-ray absorptiometry. In the growing but not finishing period, the FCR was lower (P < 0.05) in ST compared to SA and SU pigs. Considering the entire growing and finishing period, neither the inclusion level nor the type of FFPs influenced (P > 0.05) ADG, ADFI, FCR, or BW at slaughter. In both the growing and finishing periods, the gross energy ATTD was higher (P < 0.05) in the SA than in the ST group, with intermediate values in the SU group. In the growing period, the CP ATTD was higher (P < 0.05) in the SA than in the SU and ST groups. In the finishing period, the crude fibre ATTD was lower (P < 0.05) in the SA and SU than in the ST group. Throughout the overall period, the average daily fat intake was higher (P < 0.05) in pigs fed an SU diet, even though both categories of FFPs had no (P > 0.05) effects on the parameters related to the pigs' body composition (e.g., average daily fat weight gain). Finally, the carcasses of the SU group had the thickest belly fat, even though the total fat content was similar among the groups. This study confirms that including FFPs has no detrimental effects on growth performance or live body/carcass composition in growing and finishing pigs.

Review: Pig-based bioconversion: the use of former food products to keep nutrients in the food chain.

The primary challenge of agriculture and livestock production is to face the growing competition between food, feed, fibre, and fuel, converting them from resource-intensive to resource-efficient. A circular economy approach, using agricultural by-products/co-products, in the livestock production system would allow to reduce, reuse, and redistribute the resources. Former food products (FFPs), also named ex-foods, could represent a valid option in strengthening resilience in animal nutrition. FFPs have a promising potential to be included regularly in animal diets due to their nutritive value, although their potential in animal nutrition remains understudied. A thorough investigation of the compositional and dietary features, thus, is essential to provide new and fundamental insights to effectively reuse FFPs as upgraded products for swine nutrition. Safety aspects, such as the microbial load or the presence of packaging remnants, should be considered with caution. Here, with a holistic approach, we review several aspects of FFPs and their use as feed ingredients: the nutritional and functional evaluation, the impact of the inclusion of FFPs in pigs' diet on growth performance and welfare, and further aspects related to safety and sustainability of FFPs.

Review: Harmonised in vitro digestion and the Ussing chamber for investigating the effects of polyphenols on intestinal physiology in monogastrics and ruminants.

Because of the relevant effects of plant-derived polyphenols (PPs) on monogastrics and ruminants' nutrition, emissions and performance, an increasing number of in vivo and in vitro studies are being performed to better understand the mechanisms of action of polyphenols at both the ruminal and intestinal levels. The biological properties of these phenolic compounds strongly depend on their degradation, absorption and metabolism. The harmonised in vitro digestion method (INFOGEST) is one of the most reliable in vitro methods used to assess the bioaccessibility and or antioxidant activity of PP contained in different matrixes, as well as the interactions of PP and their degradation products with other feed ingredients. The effects of PP released from their matrix after in vitro digestion on different intestinal physiological parameters, such as epithelium integrity, can be further evaluated by the use of ex vivo models such as the Ussing chamber. This review aims to describe the combination of the INFOGEST method, coupled with the Ussing chamber as a valuable model for the digestion and subsequent effects and absorption of phenolic compounds in monogastrics and potentially in ruminants. The advances, challenges and limits of this approach are also discussed.

Sugary vs salty food industry leftovers in postweaning piglets: effects on gut microbiota and intestinal volatile fatty acid production.

Awareness of the need to improve the sustainability of livestock by reducing the loss of natural resources has increased significantly. This study investigated the effects of two categories of food industry leftovers, also referred to as former foodstuff products (FFPs), on pig gut microbiota and intestinal volatile fatty acid (VFA) production. Thirty-six female postweaning piglets (28 days old, Large White × Landrace, 6.5 ±â€¯1.1 kg) were separated into three groups and fed a conventional diet (CTR), and diets in which cereals were partially replaced (30% w/w) by sugary confectionery products (FFPs-C) or salty bakery products (FFPs-B), respectively. After 42 days of dietary treatments, faeces were collected from the rectal ampulla, snap-frozen, and used for next-generation sequencing to analyse the composition and the alpha and beta diversity indexes of the microbial population. The concentration of VFAs in the intestinal content collected at the slaughterhouse was also analysed. The study demonstrated that balanced diets can be obtained by the inclusion of both FFPs-C and FFPs-B, with a similar chemical composition compared to traditional diets. Neither the FFPs-C nor FFPs-B diets affected the abundance and biodiversity indexes of the microbial community. Only a few taxa, normally attributed to a healthy gut, increased with FFPs-C and FFPs-B compared to the CTR. The experimental diets had no impact on the production of the VFAs in the faeces. Lastly, the inclusion at 30% (w/w) of both categories of FFP diets slightly affected the faecal microbiota. FFPs could thus be used as a promising alternative to traditional ingredients in pig diets; however, additional analyses are needed to further investigate the presence of potentially pathogenic bacteria. The effects of such ingredients on other markers of gut health, and on product quality when used in the fattening period also need to be investigated.

Review: Insects and former foodstuffs for upgrading food waste biomasses/streams to feed ingredients for farm animals.

The increasing global need to find alternative protein/energy sources has triggered research in the field of non-conventional feed ingredients, with insects and former foodstuffs being the most promising. Insects contain high level of protein and fat, whereas former foodstuffs contain high energy in the form of carbohydrates and fats; therefore, both should be considered as promising alternative feed ingredients for livestock production. In addition to the nutritional value, they also represent a way by which food waste biomasses/streams can be upgraded to valuable feed ingredients. This review outlines the main nutritional and safety issues of insects and former foodstuffs, and also considers the legal framework involved. The importance of the type of insect metamorphosis and tailored substrates that could lead to the production of a premium feed is also described. This is also the first time that a review discusses the nutritional quality of former foodstuffs. Energy and the main nutrient content of former foodstuff are compared with the composition of common cereals as the principal energy sources in animal feed. For both ingredients a critical review of the safety issues is provided. Based on the current data available, both insects and former foodstuffs have an excellent potential use as alternative feed ingredients for livestock production. When produced in line with the criteria set by major feed/food authorities, they are characterized by high quality and safety standards. This makes them comparable to other feed materials and ingredients currently available on the market, although their full nutritional, functional, safety and sustainability evaluation cannot be considered complete.

Former food products safety: microbiological quality and computer vision evaluation of packaging remnants contamination.

The use of alternative feed ingredients in farm animal's diets can be an interesting choice from several standpoints, including safety. In this respect, this study investigated the safety features of selected former food products (FFPs) intended for animal nutrition produced in the framework of the IZS PLV 06/14 RC project by an FFP processing plant. Six FFP samples, both mash and pelleted, were analysed for the enumeration of total viable count (TVC) (ISO 4833), Enterobacteriaceae (ISO 21528-1), Escherichia coli (ISO 16649-1), coagulase-positive Staphylococci (CPS) (ISO 6888), presumptive Bacillus cereus and its spores (ISO 7932), sulphite-reducing Clostridia (ISO 7937), yeasts and moulds (ISO 21527-1), and the presence in 25 g of Salmonella spp. (ISO 6579). On the same samples, the presence of undesired ingredients, which can be identified as remnants of packaging materials, was evaluated by two different methods: stereomicroscopy according to published methods; and stereomicroscopy coupled with a computer vision system (IRIS Visual Analyzer VA400). All FFPs analysed were safe from a microbiological point of view. TVC was limited and Salmonella was always absent. When remnants of packaging materials were considered, the contamination level was below 0.08% (w/w). Of note, packaging remnants were found mainly from the 1-mm sieve mesh fractions. Finally, the innovative computer vision system demonstrated the possibility of rapid detection for the presence of packaging remnants in FFPs when combined with a stereomicroscope. In conclusion, the FFPs analysed in the present study can be considered safe, even though some improvements in FFP processing in the feeding plant can be useful in further reducing their microbial loads and impurity.

Nutritional evaluation of former food products (ex-food) intended for pig nutrition.

Ex-food or former food products (FFPs) have been proposed as one of the categories with great promise as alternative feed ingredients. FFPs' nutritional potential is not yet fully exploited. Therefore, the aim of this study was to perform a nutritional evaluation of selected FFPs. In particular, six samples of mixed FFPs, all based on bakery products, were analysed for moisture, crude protein, ether extract, crude fibre, neutral detergent fibre, acid detergent fibre, starch and ash. Nitrogen-free extractives and non-structural carbohydrate were also determined. Based on FFPs' composition data, estimation of digestible energy and metabolisable energy values for pigs were calculated. Further, the in vitro digestibility values of FFPs were investigated using a multi-step enzymatic technique. A wheat sample was included as a control feed ingredient in the study. All data were reported on dry matter basis. FFPs have shown a nutrient composition comparable with cereal grains. In the tested FFPs, the average protein content was 10.0% and the average starch content was 52.4%. Nitrogen-free extractive ranged from 61.2% to 74.7%, whereas non-structural carbohydrate ranged from 58.5% to 79.3%. Compared with wheat, FFPs were characterised by a relative high fat content, averaging about 10.1%. The relatively high nitrogen-free extractive/non-structural carbohydrate/starch and fat concentration designated FFPs as valuable energy sources. Digestible energy and metabolisable energy averages were 17.2 and 16.9 MJ kg-1, respectively. The average in vitro digestibility value of FFPs samples was 88.2% ± 5.8%, comparable with that of wheat (90.6% ± 1.6%). FFPs are a fat-fortified version of common cereals grains. The high energy content and digestibility values elect FFPs as promising non-traditional ingredients for swine.