The nutritive value of full-fat and defatted Australian rice bran. III. The apparent digestible energy content of defatted rice bran in rats and pigs and the metabolisability of energy and nutrients in defatted and full-fat bran in chickens and adult cockerels

Abstract

Apparent digestible energy (DE) content of defatted (DFRB) Australian rice bran was assessed in rats and pigs, while the metabolisable energy (ME) content and the metabolisability of chemical components of DFRB and full-fat rice bran (FFRB) were assessed in mature cockerels and young chickens. The DE of DFRB was similar for rats and pigs (11.2 and 11.8 MJ kg −1, respectively) as was dry matter digestibility (0.65 and 0.66). The ME content of DFRB was significantly lower for cockerels and chickens than that of the two FFRB samples tested. With chickens, the ME of the two FFRB samples was also significantly lower (by 5.2 and 4.1 MJ kg −1) than with cockerels and this related directly to reduced apparent metabolisability of rice-bran crude fat. Coefficients of metabolisability of crude fat of the two brans in chickens were only 0.31 and 0.43, compared with 0.94 and 0.93 for cockerels in FFRB from the cultivars ‘Calrose’ and ‘Starbonnet’, respectively.