In recent years, the free-range system for laying hens has increased, driven by societal sensitivity to animal welfare. This study aimed to comparatively analyze the total lipid, cholesterol, and fatty acid composition of egg yolks of late-age laying hens reared in enriched cages (C) and the free-range system (FR). Eggs were collected from Lohmann Brown Classic hens at the 68th, 70th, 72nd, and 74th week of age. The concentrations of total lipids and cholesterol were not affected (p > 0.05) by either factor. Egg yolk from the FR group showed lower (p < 0.01) monounsaturated fatty acids and higher (p < 0.01) polyunsaturated fatty acid (PUFA) compared with that of the C group. From a nutritional point of view, the PUFA n-6/n-3 and the PUFA/SFA ratios of egg yolk from the FR group were favorably lower and higher (p < 0.01) compared with the C one. Conversely, hen age did not affect (p > 0.05) the fatty acid composition of yolks. Interactions between factors were found for total n-3 and n-6 PUFA and the n-6/n-3 ratio (p < 0.01), as well as the thrombogenic index (p < 0.05). In conclusion, the results confirmed that the free-range system may improve the nutritional yolk fatty acid profile and its positive impact on human health.

The present study aimed to test the synbiotic PoultryStar^® sol^US delivered in ovo to evaluate its effect on hatchability, productive performance and meat quality, compared to its post-hatch administration in water. On the twelfth day of embryonic incubation, 1200 fertile eggs were divided into synbiotic groups injected with 2 mg/embryo (T1) and 3 mg/embryo (T2), a saline group injected with physiological saline and an uninjected control group (C). After hatching, 120 male chicks/group were reared and chicks from the saline group were supplemented with the synbiotic via drinking water (T3). Hatchability was low in both T1 and T2 groups. Growth performance was not affected by the treatments. However, in the second rearing phase (15–36 days), birds from the C and T3 groups were heavier than T1 birds, due to a higher feed intake and daily weight gain. Neither route of synbiotic administration influenced final body weight (at 56 days), weight and yield of the carcass or commercial cuts. Physico-chemical properties, total lipid, cholesterol and fatty acid composition of breast muscle were not affected by the treatments. Considering its exploratory nature, this study has raised many questions that need further investigation, such as the bioactive combination and the effect on embryonic development.

This study evaluated the effects of dietary supplementation with nano- and micro-encapsulated polyphenol extract (PE) from olive leaves (OL) and olive mill wastewater (OMWW), respectively, on growth, carcass and meat quality traits in Podolian young bulls. Fifteen 12-month-old bulls were assigned to three groups: C (control); T1 (40 g/day nano-encapsulated PE from OL); and T2 (400 g/day olive leaf pellets plus 30 g/day micro-encapsulated PE from OMWW) for 40 days. Final body weight and carcass yield were unaffected, although the average daily gain was higher in T2 (p < 0.05). Meat from T2 exhibited lower moisture and higher protein content (p < 0.01) compared with the other groups. T1 showed higher α-tocopherol levels (p < 0.05). Lipid oxidation was reduced in both treated groups (p < 0.01). Monounsaturated fatty acids tended to decrease in treated groups (p = 0.057), while saturated and polyunsaturated fatty acids (PUFA) were unaffected. However, T2 showed higher total n-3 PUFA (p < 0.05), and a more favourable n-6/n-3 ratio (p < 0.01) was found in treated groups. These results highlight the potential of olive–derived polyphenols as functional feed ingredients to enhance meat quality and promote sustainable, circular livestock systems.