DIGESTIBILITY OF DIFFERENTLY
PROCESSED SOYBEAN EALS IN ATLANTIC COD (Gadus morhua)
O. Forde, S. Refstie, K-A. Rorvik,
A. Skrede
Three extruded diets, added
yttrium oxide, were prepared to investigate the effect of partial replacement
of fishmeal (24% of dietary crude protein) with conventional soybean meal (SBM)
or biotechnically processed soybean meal (BP-SBM) on nutrient digestibility
in Atlantic
cod (Gadus morhua). The diets were fed to duplicate groups of 534 g (1-year-old) and
1750 g (2-year-old) cod in seawater. After 48 and 92 days of feeding, faeces
were stripped from the posterior
part of the intestine. After 92 days of feeding digestibility of fat was
significantly lower in cod fed the BP-SBM diet (75.1%) and the SBM diet
(76.0%) than in cod fed the FM
diet (87.9%). Crude protein digestibility was significantly lowered by inclusion of BP-SBM (81.9%) and SBM (83.7%) compared with the FM diet
(86.3%), and it was significantly
higher in large than in small cod. Starch digestibility was significantly higher
in cod fed the SBM diet (90.1%) and BP-SBM diet (86.3%) than in cod fed the
FM diet (79.8%).