Curcuma longa and dietary plant oils for growing rabbits: Effect on apparent digestibility

This study was set up to evaluate the effect of the inclusion of Curcuma longa (CL, 3 g kg(-1)) in rabbit diets on the apparent digestibility of mixed feeds with 40 g kg(-1) palm oil (PO) and 40 g kg(-1) corn oil (CO). Forty weaned nine week old crossbred rabbits were randomly assigned to four groups of 10 animals. The animals were housed individually under standard conditions. Four isoproteic and isoenergetic diets were formulated with CO, CO+CL, PO, and PO+CL. After 1 week for adaptation to the diets and cages, the animals were fed ad libitum for 24 days. The apparent digestibilities of the four diets were determined in the last week. The faeces were collected over a period of five days using a nylon net placed under the cages of each trial, to avoid urine contamination. The dietary and faecal samples were analysed to determine dry matter, crude protein, ash, ether extract, neutral detergent fibre, acid detergent fibre, gross energy and acid insoluble ash (AIA). The digestibility coefficients were calculated according to the indirect digestibility method using AIA as an inert marker. The analysis of variance was used to evaluate the effects on the digestibility of the four different rabbit diets. The means were compared with a Duncan test and the significance level was set at P<0.01. CL can be used satisfactorily in rabbit mixed feeds with a CO supplementation and it resulted in a better digestibility of DM, OM and GE than the control diet. In rabbit mixed feeds with a PO supplementation, CL decreased the ADF digestibility and increased the EE digestibility.