the effect of dietary
protein and lipid on juvenile halibut
T.J. Blair, J.D. Castell, S. Mercer, F. Powel-1999
Bulletin of the Aquaculture Association of Canada,
99-4: 16-18
Summary:
Growth and survival of juvenile halibut fed different
diets were compared. Four diets were formulated with constant protein (P)
levels (50%) and varied lipid (L) amounts (13 to 22%). Five diets were
isocaloric and varied in protein level (40 to 60%). The 50% diet was the
same as the 13% L, so only 8 diets were used. After 10 wk, fish fed 60% P
were significantly larger than those on other protein treatments. Protein
level affected survival, with fish fed 60% P having significantly higher
survival, followed by 55% P having significantly higher survival than diets
containing 45 or 50% P. Lipid level had no significant effect on either fish
weight or survival. Fish receiving the 60% P diet had an average feed
conversion of 1.0 +/- 1.5. Fish fed the 40% P diet lost weight and the feed
conversion value was negative. It appears that juvenile halibut have a high
protein requirement that is not spared by increasing dietary lipid.
(Department of Fisheries and Oceans, Biological
Station, 531 Brandy Cove Road, St. Andrews, NB, Canada E5B 2L9)