Total substitution of soybean meal with okara in cockerel diets in Benin: Growth performance, nutrient digestibility and carcass characteristics

The use of soy pulp or okara, in pig feed is widespread. The study aimed to evaluate the effect of dried okara-based diets on zootechnical performance and nutrient digestibility of cockerels. Thus, an eleven-week experiment was carried out on seventy-two eight-week-old Harco cockerels. The cockerels were divided into nine groups of eight based on their live weight and then randomly assigned to one of three experimental diets (F0, F10, and F20), corresponding to feed incorporation levels of 0%, 10%, and 20% dried okara. The bromatological analysis of the okara and of the three experimental diets was performed. The studied parameters were feed intake, weight gain, nutrient digestibility, and carcass characteristics. The results showed that okara had 26% protein and 3109 kcal/kg DM of metabolizable energy. Feed intake increased significantly with the okara incorporation (p < 0.05), reaching 85.81 g DM/day for diet F20. The average daily gain (14.26 to 15.06 g) and feed conversion ratio (3.84 to 4.24) were statistically similar (p > 0.05) but diet F10 had the best numerical efficiency (FCR = 3.84). The apparent digestibility coefficients of dry matter and organic matter were stable but, a significant decrease in protein digestibility was observed for the okara-based diet (72.34% to 75.20%) compared to the control (81.21%). Furthermore, diet F10 had the highest carcass yield (70.94%) and the highest eviscerated weight (1270 g). These results suggest that dried okara can be used at a rate of 10% in Harco cockerel feed without affecting growth performance while optimizing carcass yield.