Nutrigenomic Effects of Long-Term Grape Pomace Supplementation in Dairy Cows.

The increasing demand for more animal products put pressure on improving livestock production efficiency and sustainability. In this context, advanced animal nutrition studies appear indispensable. Here, the effect of grape pomace (GP), the polyphenol-rich agricultural by-product, was evaluated on Holstein-Friesian cows' whole-blood transcriptome, milk production and composition. Two experimental groups were set up. The first one received a basal diet and served as a control, while the second one received a 7.5% GP-supplemented diet for a total of 60 days. Milk production and composition were not different between the group; however, the transcriptome analysis revealed a total of 40 genes significantly affected by GP supplementation. Among the most interesting down-regulated genes, we found the DnaJ heat-shock protein family member A1 (DNAJA1), the mitochondrial fission factor (MFF), and the impact RWD domain protein (IMPACT) genes. The gene set enrichment analysis evidenced the positive enrichment of 'interferon alpha (IFN-α) and IFN-γ response', 'IL6-JAK-STAT3 signaling' and 'complement' genes. Moreover, the functional analysis denoted positive enrichment of the 'response to protozoan' and 'negative regulation of viral genome replication' biological processes. Our data provide an overall view of the blood transcriptomic signature after a 60-day GP supplementation in dairy cows which mainly reflects a GP-induced immunomodulatory effect.

Influence of Grape Pomace Intake on Nutritional Value, Lipid Oxidation and Volatile Profile of Poultry Meat.

Grape pomace (GP) represents the main solid by-product deriving from grape processing. The aim of this study was to evaluate the effect of dietary GP intake on nutritional quality, lipid oxidation and volatile profile of chicken meat. A total of 112 Ross 508 broilers were randomly divided into 4 groups and fed for 21 days with a standard diet. For the remaining 28 days of the trial, the control group (CG) continued to receive a standard diet, while the experimental groups (EGs) were fed with diets containing different GP concentrations: 2.5% (EG1), 5% (EG2) and 7% (EG3). Following the slaughtering, samples of breast meat were collected from each group. No significant differences were observed for pH, cooking loss and meat brightness, whereas the GP intake showed effectiveness in inducing variations in drip loss, meat yellowness and redness. The experimental feeding strategy also induced changes in the fatty acid profile, with an overall increase in polyunsaturated fatty acids (PUFA), mainly due to the increase in concentration of linoleic acid. The dietary supplementation also induced a decrease in lipid oxidation in meat, a finding also confirmed by the reduction in volatile aldehydes in 7 days stored raw meat. The feeding strategy based on the use of GP did not induce detrimental effects on the quality of broiler meat and showed the potential to lengthen the shelf-life as a direct consequence of the improvement in the oxidative stability. Overall, the present study showed a viable way for the recovery and the valorization of an agro-industrial by-product, with potential benefits also from an environmental point of view.

Whole Blood Transcriptome Analysis Reveals Positive Effects of Dried Olive Pomace-Supplemented Diet on Inflammation and Cholesterol in Laying Hens.

Olive pomace (OP) represents one of the by-products of the olive industry and represents an important source of bioactive compounds. This characteristic makes OP a potential feed supplement in livestock nutrition. Thus, in the last years, several studies have been published to evaluate the productive traits following OP supplementation in animal diets; however, relatively little is known from a molecular biology standpoint. Therefore, in this study, we report the RNA-sequencing analysis of laying hens fed with a 10% dried OP (DOP) supplementation. Applying a false discovery rate (FDR) <0.05 and a Log2Fc either less than -1.5 or higher than +1.5, we identified 264 differentially regulated genes (DEGs) between the non-supplemented diet control group (CTR) and the DOP group. Using the 264 DEGs to identify enriched biological pathways, we noted that cholesterol biosynthesis showed the highest enrichment followed by several pathways related to immune response and inflammation. As a consequence, when we quantified the cholesterol amount in yolk egg, we found a significant reduction in the DOP vs. the CTR group (p < 0.05). In conclusion, this study shows that DPO affects gene expression in laying hens, which is directly correlated with cholesterol decrease and can potentially ameliorate health status influencing immune response and inflammation.