Effects of Euglena gracilis Supplementation on Growth Performance, Antioxidant Status, Meat Quality in Broiler Chickens

The current growth in global demand for animal products poses significant challenges in terms of environmental, economic and nutritional sustainability. The search for sustainable alternatives has become a priority. Innovative sources, such as microalgae, fungi and agro-industrial by-products, offer opportunities to improve the nutritional quality of feed, animal welfare and the resilience of livestock supply chains, contributing to a more circular and sustainable agriculture. The purpose of this project was to evaluate the performance, health status, and meat quality of broiler chickens that had been supplemented with Euglena gracilis. In particular, a 0.019% supplementation of Euglena gracilis was administered to 240 Ross 308 male broiler chickens for 42 days. Animals were housed in two identical rooms equipped with temperature and humidity control systems. Each room contained 120 chicks, divided into 12 boxes (10 chicks/pen), with 6 boxes allocated to each treatment group. The experimental groups are as follows: CTR (Control group) and TRT (Treatment group). At the end of the test, two animals per pen were slaughtered for analysis. Subsequently, performance, meat quality and antioxidant capacity of plasma and liver were evaluated. Key parameters evaluated for performance were Average Daily Gain (ADG), Average Daily Feed Intake (ADFI) and Feed Conversion Ratio (FCR). Meat quality parameters included color, pH, Water-Holding Capacity (WHC) and myoglobin content. Antioxidant capacity was assessed by T-AOC (Total Antioxidant Capacity) and Glutathione Reductase (GR) assays. Data (mean±SEM) were analyzed with one-way Anova using GraphPad Prism 9 (p<0.05). Performance in TRT with Euglena gracilis supplementation in the broiler diet showed no significant differences compared to the control group. The animal oxidative status in TRT resulted in an enhanced liver antioxidant capacity (6.64±3.34 U/ml) and plasma GR activity (5335.43±1072.78 nmol/min/ml) compared to the CTR (4.01±0.92 U/ml and 3824.74±695.86 nmol/min/ml, respectively). Meat quality parameters showed no significant differences in TRT. These preliminary findings emphasize the role of Euglena gracilis as a sustainable and functional feed ingredient in livestock production systems, addressing challenges related to animal health and stress resilience. Research supported by Agritech National Research Center and received funding from the European Union Next-GenerationEU (PNRR – MISSIONE 4 COMPONENTE 2, INVESTIMENTO 1.4 – D.D. 1032 17/06/2022, CN00000022) grant.