A response of nutrient intakes, feed conversion ratio and digestion of meat rabbits on dietary fiber levels

Abstract

It was a complete randomized design with six treatments and three replicates, which was implemented with different levels of neutral detergent fiber (NDF) at 37, 41, 45, 49, 53 and 57% corresponding to the treatments of NDF37, NDF41, NDF45, NDF49, NDF53 and NDF57, respectively to evaluate growth performance and nutrient digestibility of growing crossbred rabbits for applications. Two female and two male rabbits at 54 days of age were allocated in one experimental unit. The results showed that in Exp 1 the dry matter (DM) and organic matter (OM) intakes were significantly increased (P<0.001) when increasing levels of NDF in the diets. The crude protein (CP) intake was the lowest value in the NDF57 diet (P<0.001). The NDF and ADF intakes were significantly increased (P<0.001) when increasing levels of NDF in the diets. The daily weight gain was significantly decreased (P<0.001), the daily weight gain in the NDF41 treatment (20.3g/rabbit/day) was higher than this in theNDF45, NDF49, NDF53 and NDF57ones, however, the lower feed conversion ratio was found (P<0.05) in the NDF37 treatment (3.45). In Exp 2 the coefficient of total tract apparent digestibility of DM, OM, NDF and acid detergent fiber (ADF) decreased when levels of NDF increased in the diets (P<0.05). The nitrogen intake of NDF37 treatment was higher than that of the NDF57 one (P<0.05), while the retained nitrogen (g/kgW0.75) of rabbits hada linear relationship with the NDF levels (%) with y=-0.008x + 1.21 (R2= 0.928, P=0.002 and SE=0.020). It was concluded that increasing levels of NDF in the diets of the meat rabbits reduced daily weight gain and nutrient digestibility andat a level of 41 % NDF in diet gave better growth performance and dietary nutrient utilization.