Abstract
Seaweeds possess a wide range of bioactive compounds that can be beneficial in sustainable intensification systems. This study explored the effect of green seaweed (Ulva spp.) meal (SWM) on apparent nutrient digestibility and physiological responses of Boschveld indigenous chickens. Two-hundred and seventy-five hens (202.4 ± 6.65 g live-weight; 4-weeks-old) were reared on five isoenergetic and isoproteic diets formulated by adding SWM at 0 (SW0), 20 (SW20), 25 (SW25), 30 (SW30), and 35 g/kg (SW35). Neutral detergent fibre digestibility quadratically responded (R(2) = 0.244; p = 0.042) to SWM levels. No significant dietary influences were observed on apparent nutrient digestibility values. Repeated measures analysis showed significant diet × week interaction effect on weekly feed intake and growth performance. Dietary inclusion of SWM increased (p < 0.05) feed intake and overall body weight gain but not feed conversion efficiency. No significant linear and quadratic trends were observed for blood parameters except for basophils (R(2) = 0.172; p = 0.047), which linearly declined with SWM levels. Dietary SWM inclusion only influenced (p < 0.05) mean corpuscular volume, mean corpuscular concentration, and mean corpuscular haemoglobin concentration. We concluded that seaweeds have the potential to be used as a feed ingredient for indigenous chickens.