Effect of several feeding
stimulants on diet preference by juvenile gibel carp (Carassius auratus
gibelio), fed diets with or without partial replacement of fish meal by
meat and bone meal
Min
Xue, Yibo Cui-2001
Aquaculture, 198 (3-4): 281-292
Abstract:
The objectives of this work were to study the effects
of several feeding stimulants on gibel carp fed diets with or without
replacement of fish meal by meat and bone meal (MBM). The feeding stimulants
tested were betaine, glycine, L-lysine,
L-methionine,
L-phenylalanine,
and a commercial squid extract. Three inclusion levels were tested for each
stimulant (0.1%, 0.5%, and 1% for betaine and 0.1, 0.25 and 0.5% for the
other stimulants). Two basal diets (40% crude protein) were used, one with
26% fish meal (FM), and the other with 21% fish meal and 6% MBM. Betaine at
0.1% in the fish meal group and at 0.5% in the meat and bone meal group was
used in all experiments for comparison among stimulants. In the experiment
on each stimulant, six tanks of fish were equally divided into two groups,
one fed the FM diet, and the other fed the MBM diet. After 7 days'
adaptation to the basal diet, in which the fish were fed to satiation twice
a day, the fish were fed for another 7 days an equal mixture of diets
containing varying levels of stimulants. Each diet contained a unique rare
earth oxide as inert marker (Y2O3, Yb2O3,
La2O3, Sm2O3 or Nd2O3).
During the last 3 days of the experiment, faeces from each tank were
collected. Preference for each diet was estimated based on the relative
concentration of each marker in the faeces.
Gibel carp fed the FM diet had higher intake than
those fed the MBM diet, but the difference was significant only in the
experiments on betaine, glycine and L-methionine. None of the feeding stimulants tested showed feeding
enhancing effects in FM diets. All feeding stimulants showed feeding
enhancing effects in MBM diets, and the optimum inclusion level was 0.5% for
betaine, 0.1% for glycine, 0.25% for L-lysine,
0.1% for L-methionine,
0.25% for L-phenylalanine,
and 0.1% for squid extract. The squid extract had the strongest stimulating
effect among all the stimulants tested.
(State Key Laboratory of Freshwater Ecology and
Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences,
Wuhan, Hubei 430072, People's Republic of China, Tel./fax: +027-8764-7664;
e-mail of Yibo Cui: yibocui@ihb.ac.cn)