High dietary inclusion of Chlorella vulgaris with extrusion or enzyme superdosing: Effects on broiler performance, welfare, and meat quality.

This study evaluated Chlorella vulgaris as an alternative feed ingredient for broilers, focusing on the effects of extrusion processing and superdosed enzyme supplementation. The objective was to assess its impact on growth performance, feed efficiency, nutrient digestibility, animal welfare parameters, and meat quality, with particular emphasis on how microalga extrusion and enzyme supplementation influence these parameters. A digestibility trial suggests that extrusion improves true metabolizable energy and amino acid bioavailability, particularly lysine and methionine, enhancing nutrient utilisation. A feeding trial investigated the effects of a 15 % dietary inclusion of Chlorella vulgaris, either untreated, extruded, or supplemented with a superdose of pancreatin, compared to a conventional maize-soybean control diet. Results indicated that C. vulgaris inclusion did not negatively affect broiler growth, with extrusion improving final body weight compared to the control. Superdosed enzyme supplementation reduced digesta viscosity. Chlorella vulgaris-fed birds, particularly the untreated group, showed minor effects on beak condition, with slightly higher feed adhesion. However, superdosed enzyme supplementation mitigated this effect. Excreta scoring remained unaffected, indicating good digestibility. Meat from Chlorella vulgaris-fed broilers showed improved nutritional quality: yellowness increased, oxidative stability improved, and a healthier lipid profile with higher n-3 polyunsaturated fatty acids and a lower n-6/n-3. The mineral composition of breast meat was enhanced, with increased potassium, phosphorus, and magnesium levels, and reduced sodium. These findings suggest that Chlorella vulgaris is a promising and environmentally more sustainable feed ingredient that supports broiler performance while enhancing meat quality. Future research should refine processing methods and inclusion strategies to maximise nutrient bioavailability and cost-effectiveness.