Nutritive value of dehydrated whole maize plant and its effect on performance and carcass characteristics of rabbits

Abstract

[EN] Seven diets were formulated in order to determine the nutritive value of whole maize plant at three stages of maturity by substitution of a control diet (C) with 20% and 40% whole maize plant at early dough, mid-dent and mature stages of grain. A digestibility trial was performed with 74 rabbits. Digestible protein and energy values of whole maize plant at different maturity stages were calculated by substitution and regression procedures. A fattening experiment was carried out with 200 rabbits from weaning (28 days of age) giving ad libitum either diet C or 20% mature whole maize plant. One hundred and forty-three rabbits were slaughtered at 63 days of age and some carcass traits were measured.The crude protein and fibre content of whole maize plant decreases as the kernel matures (CP: 8.3, 8.1 and 7.6% DM; CF: 15.8, 12.6 and 13.4% DM; NDF: 45.3, 38.0 and 38.0% DM; ADF: 19.1, 15.0 and 16.1% DM for early dough, mid-dent and mature stages, respectively). The digestible energy concentration, calculated by regression, of whole maize plant increased (P<0.01) with maturity stage (8.5, 9.5 and 10.4 MJ/kg DM, respectively) but the digestible protein value was higher (P<0.01)at the intermediate maturity stage (3.7, 4.5 and 3.2% DM). Rabbits given the diet with 20% plant maize at the maturity stage had similar feed intake (101 vs. 99 g DM/d) and live weight gain (44 vs. 45 g/d) but a worse feed conversion index than C rabbits (2.29 vs. 2.21, P=0.03). No differences were found at slaughter in live weight, carcass characteristics and dressing percentage of rabbits fed the two experimental diets.