New sustainable sources of feeds, which can enhance the health and welfare of farm animals, lower feeding costs, and lead to safer products, are of high priority in modern animal production systems. In the present study, a novel silage created from Greek olive, winery, and feta cheese waste by-products, was evaluated as a feed ingredient at different inclusion rates (0%, 5% or 10%) in 34-day-old weaned pigs. The potential beneficial effects on performance, health and intestinal digesta microflora balance of the pigs were evaluated. Additionally, chemical, microbiological and quality analysis of the meat was carried out. Results showed no detrimental effects (p > 0.05) on the pigs’ performance and no significant changes (p > 0.05) in meat pH, color and chemical analysis. Ileum and cecum microflora populations (total anaerobes, Lactobacillaceae) were positively affected (p ≤ 0.05) by the dietary usage of the silage. The microbial populations (Clostridium spp.) of belly meat cuts were positively modified (p ≤ 0.01). The concentration of total phenols in the meat cuts were increased (p ≤ 0.05) and their resistance to oxidation was improved (p ≤ 0.05). In addition, the fatty acid profile of the meat lipids (polyunsaturated and n-3 fatty acids) was positively modified (p ≤ 0.001).

Incorporating agricultural by-products into animal diets represents a sustainable strategy to enhance animal health and product quality. Olive leaves, rich in bioactive compounds such as oleuropein, exhibit notable antioxidant, antimicrobial, and anti-inflammatory properties. This study evaluated the effects of dietary supplementation with an environmentally friendly, oleuropein-enriched OLE (OLE) on broiler chickens. A total of 480 day-old chicks were randomly assigned to four groups: a control diet - CF (T1), CF + 1 % OLE (T2), CF + 2.5 % OLE (T3), and CF + 0.1 % encapsulated oregano oil (T4, positive control). Over 42 days, growth performance, carcass characteristics, intestinal morphology, foot pad health, and meat quality were assessed. While T4 showed superior growth performance, the 1 % OLE diet significantly improved intestinal morphology and meat quality. A dose-dependent yellow pigmentation of the foot pad was observed in OLE-treated groups. Additionally, breast tenderness and darker thigh coloration improved in OLE-fed broilers. These findings suggest that 1 % OLE can be a viable natural additive to support gut health and meat quality in broilers, with comparable antioxidant effects to oregano oil and no adverse outcomes.

This study aims to evaluate the effects of two phytobiotic mixtures on performance, nutrient digestibility, histomorphology, microbiota, and antioxidant status in fattening ducks. A total of 180 day-old male mixed-type ducks were randomly assigned to three dietary groups: a control group receiving a basal diet, and two treatment groups (PM1: commercial phytobiotic formulation containing menthol, eucalyptus oil and turmeric leaf oil as key ingredients and PM2: commercial phytobiotic formulation containing garlic oil as a key ingredient) supplemented at 250 g/ton of feed. Ducks were reared for 49 days with six replicates of ten ducks. Performance parameters, including body weight (BW), body weight gain (BWG), and average feed intake (AFI), were significantly improved in phytobiotic groups (p ≤ 0.05). Apparent digestibility of dry matter, crude protein, ether extract, and starch remained unaffected (p > 0.05). Histological analysis showed no significant differences in villus height (VH) or crypt depth (CD). However, cecal microbiota culture-based analysis revealed increased total anerobic bacteria and Lactobacillus counts in PM1 and PM2 (p ≤ 0.05). Antioxidant status demonstrated reduced MDA levels and elevated total phenolic content (TPC) and total antioxidant capacity (TAC) in breast and thigh tissues of treated ducks. Overall, phytobiotic supplementation improved performance and microbiota balance, supporting the potential application of these phytobiotic formulations at the inclusion level of 250 g/ton in fattening ducks’ nutrition.