Dietary vitamin E
requirement, fish performance and carcass composition of rohu (Labeo
rohita) fry
S.K. Sau, B.N. Paul, K.N. Mohanta, S.N. Mohanty-2004
Aquaculture, 240(1-4): 359-368
Abstract:
A 90-day feeding experiment was conducted using flow
through system to evaluate the requirement of vitamin E for rohu fry in
relation to growth performance and to assess the relationship between the
dietary vitamin E levels and carcass composition. Five semi-purified diets
supplemented with 0, 50, 100, 150, 200 mg vitamin E/kg dry diet as DL-α-tocopheryl
acetate were fed to rohu fry (av. wt.±S.E.=0.58±0.01 g) in triplicate
groups. At the end of the experiment, growth and dietary performance were
evaluated and vitamin E deposition in the tissue, erythrocyte fragility,
thiobarbituric acid reactive substances (TBARs) were analyzed. The average
net weight gains were 6.82±0.09, 7.38±0.03, 8.20±0.03, 8.07±0.09 and
8.12±0.08 (g/90 days), respectively, for fish fed diets 0, 50, 100, 150,
200 mg vitamin E/kg. The fish fed diets containing less than 100 mg
supplemental vitamin E/kg had significantly (P<0.05) reduced
weight gain, feed efficiency and other nutritional indices compared to those
fed diets supplemented with vitamin E at 100–200 mg/kg. With the
increasing level of vitamin E, both TBARs and erythrocyte fragility values
were reduced. Regression analysis of weight gain data using broken-line
model indicated a minimum vitamin E requirement of 131.91 mg/kg dry diet.
The erythrocyte fragility and TBARs were maximum in fish fed the vitamin
E-deficient diet. From the present experiment, it may be concluded that the
vitamin E requirement of Labeo rohita fry for optimum growth and
other dietary performances is 131.91 mg/kg of dry diet.