EVALUATION OF GROWTH RESPONSE AND NUTRIENT DIGESTIBILITY OF BROILER BIRDS FED DIETS SUPPLEMENTED WITH ENZYME-TREATED BOILED AERIAL YAM (DIOSCOREA BULBIFERA) MEAL.

Abstract

This study investigates broiler chickens' growth response and nutrient digestibility over a four-week feeding trial utilizing diets supplemented with enzyme-treated boiled aerial yam (Dioscorea bulbifera) meal. The aerial yam was processed by peeling, boiling at 100 °C, milling, and incorporated into diet formulations. Five diets were formulated: Treatments 1 (T1) and 2 (T2) contained maize as the primary energy source, acting as positive and negative control groups, respectively. Treatment 2 was further supplemented with 0.2% enzyme. Treatments 3 (T3), 4 (T4), and 5 (T5) had a progressive replacement of maize with 20%, 40%, and 60% aerial yam meal, respectively, and each of these treatments was additionally supplemented with 0.2% of the multi-grade enzyme Rozayme-2G. A total of 150 Ross 308-day-old broiler chicks, with an average initial weight of 40.72 ± 10 g per bird, were randomly allotted into the five treatment groups, employing a completely randomized design (CRD) with 30 birds assigned to each group. Three birds per treatment were selected, weighed, and placed in metabolic cages for a digestibility trial. The results revealed that broiler chickens fed the T4 diet exhibited the highest average daily weight gain, measured at 59.87 g, alongside a superior feed conversion ratio (FCR) of 3.36. Furthermore, the treatments displayed varying degrees of nutrient digestibility; T5 recorded the highest digestibility of crude fat at 98.82%, T4 exhibited the highest digestibility of crude fiber at 86.72%, and T3 demonstrated the highest gross energy digestibility at 98.32 kcal/kg. In conclusion, the incorporation of the

Rozayme-2G enzyme at a level of 0.2% facilitates the replacement of up to 60% of maize with boiled aerial yam meal in the diets of broiler chickens, supporting optimal growth and health outcomes.