According to statistics and future predictions, meat consumption will increase in the coming years. Considering both the environmental impact of intensive livestock farming and the importance of protecting animal welfare, the necessity of finding alternative strategies to satisfy the growing meat demand is compelling. Biotechnologies are responding to this demand by developing new strategies for producing meat in vitro. The manufacturing of cultured meat has faced criticism concerning, above all, the practical issues of culturing together different cell types typical of meat that are partly responsible for meat’s organoleptic characteristics. Indeed, the existence of a cross talk between adipose and muscle cells has critical effects on the outcome of the co-culture, leading to a general inhibition of myogenesis in favor of adipogenic differentiation. This review aims to clarify the main mechanisms and the key molecules involved in this cross talk and provide an overview of the most recent and successful meat culture 3D strategies for overcoming this challenge, focusing on the approaches based on farm-animal-derived cells.

The availability and cost of fishmeal constitute a bottleneck in Atlantic salmon production expansion. Fishmeal is produced from wild fish species and constitutes the major feed ingredient in carnivorous species such as the Atlantic salmon. These natural stocks are at risk of depletion and it is therefore of major importance to find alternative protein sources that meet the nutritional requirements of the Atlantic salmon, without compromising the animals’ health. Terrestrial animal by-products have been used in aquaculture feed, but their use is limited by the lack of several essential amino acids and consumer acceptance. In the case of plant ingredients, it is necessary to take into account both their concentration and the extraction methodologies, since, if not dosed correctly, they can cause macro- and microscopic alterations of the structure of the gastrointestinal tract and can also negatively modulate the microbiota composition. These alterations may compromise the digestive functions, growth of the animal, and, ultimately, its well-being. An updated revision of alternative protein sources is provided, with the respective impact on the intestine health in terms of both morphology and microbiota composition. Such information may constitute the premise for the choice and development of Atlantic salmon feeds that guarantee fish health and growth performance without having a significant impact on the surrounding environment, both in terms of depletion of the fish’s natural stocks and in terms of pressure on the terrestrial agriculture. The sustainability of aquaculture should be a priority when choosing next-generation ingredients.

The success of cell-based approaches for the treatment of cartilage or fibro-cartilaginous tissue defects requires an optimal cell source with chondrogenic differentiation ability that maintains its differentiated properties and stability following implantation. For this purpose, the aim of this study was to evaluate the use of endostatin (COL18A1), an anti-angiogenic factor, which is physiologically involved in cell differentiation during meniscus development. Swine neonatal meniscal cells not yet subjected to mechanical stimuli were extracted, cultured in fibrin hydrogel scaffolds, and treated at two different time points (T1 = 9 days and T2 = 21 days) with different concentrations of COL18A1 (10 ng/mL; 100 ng/mL; 200 ng/mL). At the end of the treatments, the scaffolds were examined through biochemical, molecular, and histochemical analyses. The results showed that the higher concentration of COL18A1 promotes a fibro-chondrogenic phenotype and improves cellularity index (DNA content, p < 0.001) and cell efficiency (GAGs/DNA ratio, p < 0.01) after 21 days. These data are supported by the molecular analysis of collagen type I (COL1A1, a marker of fibrous-like tissue, p < 0.001), collagen type II (COL2A1, a marker of cartilaginous-like tissue, p < 0.001) and SRY-Box Transcription Factor 9 (SOX9, an early marker of chondrogenicity, p < 0.001), as well as by histological analysis (Safranin-O staining), laying the foundations for future studies evaluating the involvement of 3D endostatin hydrogel scaffolds in the differentiation of avascular tissues.

The permeability of the immature intestine is higher in newborns than in adults; a damaged gut barrier in young animals increases the susceptibility to digestive and infectious diseases later in life. It is therefore of major importance to avoid impairment of the intestinal barrier, specifically in a delicate phase of development, such as weaning. This study aimed to evaluate the effects of bovine colostrum supplementation on the intestinal barrier, such as the intestinal morphology and proliferation level and tight junctions expression (zonulin) and enteric nervous system (ENS) inflammation status (through the expression of PGP9.5 and GFAP) in fattening rabbits. Rabbits of 35 days of age were randomly divided into three groups (n = 13) based on the dietary administration: commercial feed (control group, CTR) and commercial feed supplemented with 2.5% and 5% bovine colostrum (BC1 and BC2 groups, respectively). Rabbits receiving the BC1 diet showed a tendency to have better duodenum morphology and higher proliferation rates (p < 0.001) than the control group. An evaluation of the zonulin expression showed that it was higher in the BC2 group, suggesting increased permeability, which was partially confirmed by the expression of GFAP. Our results suggest that adding 2.5% BC into the diet could be a good compromise between intestinal morphology and permeability, since rabbits fed the highest inclusion level of BC showed signs of higher intestinal permeability.

This study provides a morphological characterization of the thigh and Semimembranosus muscle (SM) of the Nero di Lomellina (NL) pig, considering two different rearing periods, December-October (rearing period 1) and September-July (rearing period 2), and using a commercial crossbreed (CH) as a reference. Fat content in the thigh was evaluated using computed tomography, while SM characteristics were assessed by comparing muscle fiber area, density, and total number. Fiber type composition was determined by immunofluorescence and molecular analyses through the localization and expression of myosin isoforms, including MyHC I, MyHC IIb, and MyHC IIa/x (red slow oxidative, white fast glycolytic, and intermediate fast oxidative glycolytic fibers, respectively). Additionally, physicochemical analyses were conducted to assess muscle quality. The results showed that both breeds had higher intermuscular fat deposition in the rearing period 2. In period 1, NL pigs exhibited larger muscle fibers than CH pigs, whereas no differences were observed in period 2. Immunofluorescence revealed that CH pigs in period 2 had a higher proportion of red and intermediate fibers, while NL pigs showed no significant changes in fiber composition related to the rearing period. In conclusion, lower temperatures in period 2 promoted an oxidative phenotype in CH, whereas NL pigs showed greater stability across rearing periods and better adaptability to temperature fluctuations. These findings suggest that NL pigs exhibit greater resilience to environmental changes, supporting previous studies on breed-specific responses to temperature variation.

A feeding trial with alternative protein sources was conducted in gilthead seabream ( Sparus aurata , L.) broodstock fed a control diet and two diets with 5% or 10% inclusion levels of a blend of novel ingredients. The blend is composed of 40% insect ( Hermetia illucens ), 10% duckweed ( Lemna minor ), 45% Nannochloropsis gaditana , and 5% Alaria esculenta meal dry biomass. The animals were reared in a recirculating aquaculture system and administered the experimental diets 3 months before spawning and for a total of 7 months. Fertilized eggs were incubated until hatching and newly hatched larvae were monitored until the yolk sac absorption stage. High inclusion (HI; 10%) of novel ingredients to broodstock resulted in a significantly higher hatching rate, while both groups fed novel ingredients produced offspring with significantly higher survival until the end of the yolk sac stage compared to offspring from parents fed the control diet ( p < 0.05). The inclusion of the protein blend at any level did not produce differences in larval growth. Morphological and histometric analyses in larvae revealed hypertrophic growth during the yolk sac stage. The expression of genes involved in muscle development and growth indicated no differences in growth potential in larvae between groups. Overall, broodstock feeds for gilthead seabream can have an inclusion of novel ingredients without a negative impact on larval performance and growth. Further studies are needed to study the long‐term effects of broodstock diet on offspring quality.