Effects of passion fruit seed (Passiflora edulis) on performance, carcass traits, antioxidant activity, and meat quality of growing rabbits

Abstract

Two experiments were carried out to determine the nutritional value of passion fruit seed (PFS) and the effects of dietary supply of this feedstuff on performance, carcass traits, meat quality, biochemical parameters, and economic viability of growing rabbits. In the digestibility experiment, 24 rabbits (12 males and 12 females) were allocated between 2 treatments (reference diet and test diet, composed by 70 % reference diet and 30 % PFS). The PFS contained 119.3 g/kg crude protein (CP), 218.2 g/kg ether extract (EE), 656.6 g/kg neutral detergent fibre (aNDFom), 625.5 g/kg acid detergent fibre (ADFom) and 9.4 MJ DE/kg dry matter. In the performance experiment, 100 rabbits (50 males and 50 females) were allocated in a 5 × 2 factorial design study, with five inclusion levels of PFS (0, 40, 80, 120 and 160 g/kg) and 2 genders. PFS promoted a linear increase on the activity and potential antioxidant of blood, meat color, and DM, CP and EE digestibility (P < 0.05). The inclusion of PFS had a quadratic effect on body weight gain (BWG), final weight and carcass weight of growing rabbits, with best levels estimated at 88.7, 78.5, 80.0 g/kg, respectively (P < 0.05). Dietary supply of PFS resulted in an efficient transfer of antioxidant compounds in rabbit meat (P < 0.05). PFS supply in rabbits’ diets linearly increased the economic efficiency index (EEI), and reduced the cost index (CI) and average feed cost per kilogram of bodyweight (P < 0.05). Male rabbits had higher values (P < 0.05) of BWG and EEI, and lower value of CI than female (P < 0.05). Dietary inclusion of PFS positively affects performance, carcass traits, meat quality, and antioxidant status of growing rabbits, and is economically feasible up to 160 g/kg. Male rabbits have better performance and economic variables than females.