EFFECT OF CHOLINE AND LECITHIN ON GROWTH AND FEED EFFICIENCY OF JUVENILE HUMPBACK GROUPER , Cromileptes altivelis

This experiment was conducted to determine the effect of supplemental choline and lecithrn in the diet of juvenile humpback grouper. Four treatments were designed in a 2x 2 factorial desrgn and diets containing 0% or 8% lecithin and 0% or 0 9% choltne chloride were fed to hatchery produced.luvenile of 3.9 t 0.2 gram body weight. They were reared rn 30 liter polycarbonate tank and stocked 15 fish in each tank. All tanks were equipped with flowthrough system. Fish were fed with experimental diet three times a day for 7 weeks. The results of the experiment showed that the groMh and feed efficiency of humpback grouper were affected by supplemental choline and lecithin. An interaction effect was observed between supplemental dietary choline and lecithin on fish weight gain (192 5% to 240.5o/o) and feed efficiency (46.9% to 73.29%). KEYWO RDS : choline, lecith in, h u mpback grou per, Cro mile ptes altivel i s


INTRODUCTION
Choline is generally classified as an essential vitamin by most comparative nutritionists.This substance is an important component of phospholipid leci- thin and cet1ain other complex lipids.lt serves as a source of labile methyl groups for synthesis of various ethylated metabolites and as precursor of acetylcholine.Most animals can synlhesize choline if adequate methyl donors such as methionine are present in the diet.The rate of choline synthesis has been shown to be insufficient to meet the metabolic and physiologic needs in some young animals (Wilson   and Poe 1988).Therefore, choline should be presented in the diet for normal growth.
Dietary essentiality and deficiency signs of choline have been reported on common carp (Ogeno ef   a/., '1970), red sea bream (Yano, 1975), Japanese eel (Arai ef al., 1972) and red drum (Craig and Galtin,   1997).Deficiency signs have been reported to include poor groMh and feed efficiency, anorexia and fatty liver.
Some information is available on the requirement of choline for fish.The choline requirement of common carp appears to be not more than 1,500 mg/kg of diet (Ogeno et al., 1970).Halver (1972) reported that Chinook and Coho salmon require 600-800 mg choline/kg of diet based on maximum liver storage data.Hung et al. (1987) showed that juvenile white sturgeon fed purified diet containing 8% refined soybean lecithin had better growth when compared to those fed diet without lecithin.Dietary sources of phos- pholipid such as soybean lecithin were essential for oroMh and survival of red sea bream and flatfish (Kanazawa et a|.,1985 and Kanazawa, 1993, 1997).These studies also suggested that soybean lecithin may be required by hatchery produced juvenile hump backgrouper.The present research was conducted to determine the effect of supplemental choline and lecithin in the diet of juvenile humpback grouper.

MATERIALSAND METHODS
Formulation and proximate compositions of the four experiment diets are shown in Table 1 .The fourtreatments were designed in a 2x2faclorial design, and the diets contained Oo/o ot 8% soy lecithin (Loc) and 0% or 0.9% choline chloride (Ch).

RESULTS AND DISCUSSION
Initial average body weight of humpback grouper, Cromileptes altivelis was 3.9 g and increased from 192.5% lo 240/% after 7 weeks.An interaction ef_ fect was observed between different dietary choline and lecithin treatments on fish weight gain (192.5oh   to 240.5o/o) and feed efficiency (46.9% lo 73.29o/o), but not on feed intake (13.19 to 16.1g) (Table 2).
Analysis of variance showed that weight gain, feed intake, feed efficiency, and hepatosomatic index (HSl= liver weight/body weight x 100%) were significanfly affected by both supplements (p<0.05).Humpback grouper fed with the control diet (diet l) had signifi_ cantly lower percentage weight gain and feed efficiency and higher feed intake than those fed with diets either one or both supplements (diets ll, lll, or lV).The weight gain of humpback grouper fed with the diet supple_ mented with lecithin (diet lt) was significanily lower 2 than those fed diet with diets ilt and lV.The feed efficiency of humpback grouper fed with diets ll and lll was not significantty different, but fish fed with diet ll was significantly lowerthan those fed diet with both supplements (diet lV).The HSI of humpback grouper fed with diets containing supplemental choline or lecithin or lecithin and choline (diet ll, lll, and lV) was not significant (P<0.05)but significanfly higher than that fed with diet control (diet l).The results of this experi_ ment showed that to attain good groMh humpback grouper may require choline and lecithin.The same result was found on juvenile white sturgeon, Accidence transmontanus (Hung and Lutes,19SS).
Table 3 shows that the dry matter of liverwas not affected by dietary choline or lecithin, but on the con_ trary.dietary choline and lecithin affected lipid con_ tent of the liver.Wilson and poe (199S) showed that liver lipid content of channel catfish was affected by dietary choline.This observation is also consistent 5.89 t O.soub 6.05 r 0.59b ' % wetght garn = 1O0x(Buff -Bow)/Bow, where Buff = the average final body weight and Bow = the average initial body weight 2 Feed intake = sum of daily feed intake (dry weight)/0.5(number of flsh at initial + number of survival fish at end) 3 Feed efficiency = weight gain (g)lfeed intake o HSI = Liver weighVbody weight x 100% with the result of the choline study conducted by Craig than lecithin per se.This hypothesis is supported by and Galtin (1997) for juvenile red drum (Sciaenops the observation in the present experiment that hump- ocelafus).
backgrouperfed with diet lllgrewsignificantly better than those fed with the diet ll.Furthermore, there were Finfish are capable of synthesizing lecithin de novo no differences in weight gain and feed efficiency of like other terrestrial and aquatic animal (Lee and humpback grouper fed with the diet containing 0.9% Sinnhuber, 1972).Therefore,thebeneficialeffectof cholinechloridewithoutlecithinascomparedtothose the diet containing 8% lecithin and no supplemental fed with diet containing 0.9% choline chloride and 8% choline chloride on growth of humpback grouperwere lecithin.The ability of humpback grouper to utilyse probably due to the choline moiety (28.2o/o phosphatiphosphatidylcholine for their choline requirement in- dylcholine in the lecithin;  Recently, various experimental results have shown the beneficial effects of dietary phospholipid supple- mentation in larval and juvenile stages of several spe- cies of fish such as European sea bass and carp (Guerdon et at., 1995 a, b), Japanese flounder (Tago   et a!.,1999) and red sea bream (Kanazawa, 1997).
The essentiality of phospholipid for aquatic animals is assumed to be due not only to limited ability for phospholipid biosynthesis from diglyceride, but also to its function as an emulsifier of triglycerides and cholesterol, and as a constituent of lipoproteins es- sential for the transport of lipid.

CONCLUSION
J u ve n i le h u m pback g rou pe r (Crom ile pte s aftive Ii s) requires dietary choline and lecithin for good growth' Dietary choline is superior to dietary lecithin for their growth.

Table 1 .
05, j Researcher at Research Institute for Mariculture.Gondol.Bali.lndonesia Composition of the four experiment diets

Table 2 .
Weight gain (%), feed efficiency (o ), and feed intake of juvenile humpback grouperfed with four experimental diets for 7 weeks means with different superscripts (a, b, c) for each parameter are significantly different (p<0.05)

Table 3 .
Dry matter and lipid content of liver of humpback grouper fed with diets containing

Table
1, footnote 3) rather dicatesthatthese fish may possess a phospholipase- D which can release choline from the phosphatidyl- choline (Table1, footnote 3)" Further studies are needed to isolate and to determine the activity of phospholipase-D to confirm the ability of humpback grouper to use dietary lecithin.These results suggest that choline is superior to lecithin for humpback grouper in the present study.Other studies are needed to determine the real choline requirement of humpback grouper.