The optimal rate of soybean (Glycine max) pods in rabbit (Oryctolagus cuniculus) feed: digestibility study and growth performances

Abstract

A study was undertaken to determine the optimal rate of soybean pods in the growing rabbit feed. Soybean pods were incorporated in balanced feed at 0, 5, 10 and 15% to evaluate the digestibility of diets and its effect on the bioeconomic performances of growing rabbits. A total of 80 young rabbits of 42 to 49 days-old and weighting on average 605g to 611g were kept during 8 weeks. The experimental design was a randomized complete block with 4 treatments and 5 replications of 4 rabbits each. The results showed that the average body live weight (1290g) and daily weight gain (12g) of rabbits fed the control diet (F0) were significantly lower (P<0.05) than those of rabbits fed F5 (1843g; 22g) and F10 (1848g; 22g). However, no significant difference (P>0.05) was found between the average body weight and the average daily gain of rabbits fed F0 and F15 (1612g; 18g). Feed intake of rabbits fed F0 (42g) was significantly lower (P<0.05) than that fed F5 (67g), F10 (70g) and F15 (65g). The feed conversion ratio was similar (P>0.05) in F0 (4.75), F5 (3.00), F10 (3.18) and F15 (3.83). The mortality rate was also similar (P>0.05) in F0 (25%), F5 (20%), F10 (25%) and F15 (25%). At the end of the growth period, 6 rabbits per treatment were sampled for a digestibility study. The apparent digestibility of the dry matter and organic matter in F5, F10 and F15 was lower (P>0.05) than in F0. The digestibility of crude protein was also lower (P>0.05) in F0 (63.20%) than in F5 (67.55%), F10 (72.23%) and F15 (66.94%). Economically, no significant difference (P>0.05) was noticed concerning the feeding cost and the economic feed efficiency. Furthermore, F5 and F10 diet improved these economic variables compared to F0 and F15. Thus, up to 10% of soybean pods can be used efficiently in the growing rabbit feed.