Publication Date:
2021-05-19
Description:
Growth experiments were designed and conducted in several phases in order to determine the most suitable
starter diet, to determine the effects of different levels of protein and energy and also to determine the effects of
different ratios of carbohydrate to fat on growth and body composition in farmed Huso huso from the larval
stage up to the marketing stage.
Phase one
Growth experiments were conducted in a random statistical design to compare growth trends in H. huso larvae
(mean weight 105.02 ± 0,02 mg) without being adapted to formulated diets. Experiments were conducted in
fibreglass tanks (500 litre capacity) under similar culture conditions. Four replicates were run for each
experiment. Larvae were fed four types of formulated diets (Diet A=100 % formulated diet produced in the
International sturgeon Research Institute, Diet B=formulated diet imported from Holland, Diet C= formulated
diet imported from France, Diet D= a mixture of Diet A + 10% gammarus) 8 times a day to satiation for a period
of 49 days. The results obtained were compared with those obtained for the control group that was fed live food
(Daphnia and Artemia). Mean water temperature during the experimental period was 18.52 ± 0.48 ?C and mean
dissolved oxygen was 7.35 ± 0.18 mg/l. The first signs of food granules were observed in the guts of the larvae
after 12 h of the first feeding. All experimental groups were adapted to granulated diets on day 3 to day 5. In the
beginning of the experimental period the larvae showed a no normal distribution (P 0.05) in terms of weight and
length. However significant differences were observed in the end of the experimental period among the different
groups studied in terms of growth, specific growth rate and food efficiency (P 0.05). Growth in group B and D
were significantly higher than that in other groups except for the control group (P 0.05). It may thus be
concluded that the olfactory organs of larvae took to Diet B (may be due to its composition) and to the diet D
(because of its odour, texture and suitable flavour) more readily than other diets.
At the end of the experimental period, maximum survival (98%) belonged to the control group. Survival rate in
Group B and Group D was 90 % and 86.5%, respectively (P 0.05). Minimum survival belonged to fish fed Diet
A (29.7%) and Diet C (45.5%). With regard to the adaptability of larvae to formulated diets, survival rates and
growth and development in larvae we may conclude that the effects of different formulated diets on growth in
larvae can be conducted on larvae with a mean body weight between 100 to 120 mg. In this weight class the
digestive system and olfactory organ are fully developed and play a vital role in searching for food particles.
Description:
Iranian Fisheries Science Research Institute
Description:
Published
Keywords:
Huso huso
;
Protein to energy ratio
;
Carbohydrate to fat ratio
;
Body composition
;
SGR
Repository Name:
AquaDocs
Type:
Report
,
Refereed
Format:
254pp.
