Alternatives to antibiotic treatments are required owing to the ban on the use of these drugs as growth promoters in food animal production. Tributyrin appears to play a role in improving growth performance in pigs, albeit with varying degrees of effectiveness. So far, very little is known about its effects on gut microbiota composition. In this study, we investigated the gut microbiota changes of piglets receiving, at weaning, 0.2% tributyrin added to their basal diet. Microbiota composition was assessed through 16S-rRNA gene sequencing on stools collected from tributyrin and control groups. The functional profiles of microbial communities were predicted from amplicon abundance data. A comparison between dietary groups revealed that tributyrin strongly modulated gut microbiota composition in piglets, increasing the relative abundance of a number of bacterial genera such as Oscillospira, Oscillibacter, Mucispirillum and Butyrivibrio. These genera were positively correlated to animal average daily gain (ADG) and/or body weight (BW). Based on the function profile prediction, the gut microbiome of the tributyrin group possessed an enhanced potential for energy metabolism and a reduced potential for carbohydrate metabolism. In conclusion, our results indicated that tributyrin can promote changes to gut microbial communities, which could contribute to improving animal performance after weaning.

Ripening time is known to drive the chemical and sensory profiles of dry meat products, thus potentially affecting the final quality of the product. Starting from these background conditions, the aim of this work was to shed light, for the first time, on the chemical modifications of a typical Italian PDO meat product—namely, Coppa Piacentina—during ripening, to find correlations between its sensory quality and the biomarker compounds related to the progress of ripening. The ripening time (from 60 to 240 days) was found to deeply modify the chemical composition of this typical meat product, providing potential biomarkers of both oxidative reactions and sensory attributes. The chemical analyses revealed that there is typically a significant decrease in the moisture content during ripening, likely due to increased dehydration. In addition, the fatty acid profile showed that the distribution of polyunsaturated fatty acids significantly (p < 0.05) decreased during ripening, because of their high susceptibility to oxidation and conversion to intermediate and secondary molecules. An untargeted metabolomics approach, coupled with unsupervised and supervised multivariate statistics, highlighted a significant impact (prediction scores > 1) of lipid oxidation during ripening time, with some metabolites (such as γ -glutamyl-peptides, hydroperoxy-fatty acids, and glutathione) being particularly discriminant in predicting the changes observed. The discriminant metabolites were coherent with the progressive increase of peroxide values determined during the entire ripening period. Finally, the sensory analysis outlined that the highest degree of ripening provided greater color intensity of the lean part, slice firmness, and chewing consistency, with glutathione and γ-glutamyl-glutamic acid establishing the highest number of significant correlations with the sensory attributes evaluated. Taken together, this work highlights the importance and validity of untargeted metabolomics coupled with sensory analysis to investigate the comprehensive chemical and sensory changes to dry meat during ripening.

The nutritional performance of three high-protein maize hybrids was compared with conventional maize in a 42-day feeding trial in broilers. The following experimental diets were compared: i) control diet (CTR) containing conventional maize; ii) diet containing hybrid IPM1; iii) diet containing hybrid IPM2; iv) diet containing hybrid IPM3. The diets were offered to male broilers (Hubbard Ultra-Yield; 120 birds per treatment) in 3 phases: starter, grower and finisher. All the diets were iso-nitrogenous and iso-energetic. The IPM2 and IPM3 diets (containing maize grains with the highest protein and essential and non-essential amino acid contents) resulted in a higher final weight in broilers (2622 and 2632 g, respectively, versus IPM1 and CTR diets; P<0.05), a higher average daily gain (60.8 and 61.4 g/d, respectively, versus IPM1 and CTR diets; P<0.05) and better feed to gain ratios (1.70 and 1.69, respectively, versus the CTR diet; P<0.05) throughout the experimental period. The nutritional characteristics of the different maize varieties were also evaluated using a 9-day digestibility trial in male rats (6 rats per treatment). Higher percentages of nitrogen retention were obtained from the IPM2 (54.02%) and IPM3 (53.51%) diets compared with the CTR (44.20%) and IPM1 (41.87%) diets (P<0.05). These results suggest a greater amino acid availability in the diets based on high-protein maize varieties. Therefore, high-protein maize can profitably be included in broiler diets with the advantage of reducing the use of imported protein sources (such as soybean meal) because of its higher protein content and consequently, providing savings on feed costs.