Utilization of dietary protein, lipid, and carbohydrate by abalone Haliotis discus hannai: a review.

ABSTRACT Feeding Haliotis discus hannai depends mainly on the use of macroalgae such as Undaria sp. or Laminaria sp., although the species is an important mariculture shellfish in Korea. Research on the utilization of protein, lipid, and carbohydrate in formulated diets by H. discus hannai has been conducted, and the results have been reviewed. H. discus hannai fed a formulated diet showed better growth performance than those fed a macroalgae based-diet. Casein, fish meal, soybean meal, cottonseed meal, and wheat germ meal are all good sources of dietary protein for H. discus hannai. The optimum dietary lipid content for H. discus hannai is from 2% to 5%. Marine fish oil, for instance squid liver oil, is a good dietary lipid source for H. discus hannai. Oil supplementation in diets is not necessary when fish meal as main protein source is used for H. discus hannai diets. Comparative growth rates were observed when H. discus hannai were fed diets containing each of the following carbohydrate sources: wheat flour, dextrin, sucrose, potato starch, or as a mixture combined with practical ingredients such as soybean meal, corn gluten meal, cotton seed meal, and wheat flour. These results may be used in developing practical feed formulation and improving aquaculture production of abalone.

KEY WORDS: Haliotis discus hannai, formulated diet, protein, lipid, carbohydrate

INTRODUCTION

Huliotis discus hannai is a commercially important shellfish species in Asia, especially, in Korea, China, and Japan. This species has several desirable characteristics for aquaculture including tolerance to low water temperatures, establishment of seedling production, and ability to withstand high stocking density (Kikuchi & Uki 1974, Uki & Kikuchi 1982, Kim et al. 1998). Farming of H. discus hannai in Korea has been developed since 1970, and aquaculture production is currently increasing at a rapid rate. It is likely to maintain this increasing trend in the production because of the decrease in wild abalone captures due to overexploitation, water pollution, and other causes. In culturing H. discus hannai, juvenile abalone are reared on diatoms cultured on plates until they grow up to about 5-mm shell length and then weaned on to marine macroalgae.

Abalone has a slow and very heterogeneous growth rate. The growth rate of H. discus hannai is approximately 1-2 cm in shell length per year depending on environmental conditions such as water temperature and food. The economic success of abalone aquaculture depends in part on the abalone growth during culture. Nutritional quality of feed is critical, among many factors affecting growth and survival of animals. In the wild, H. discus hannai eat mainly macroalgae, such as Undaria and Laminaria, which are predominated in Korea. It would be expensive to maintain or to culture an adequate supply of live algae. Lee et al. (1997) investigated the effects of experimental formulated diets, commercial diets, and Undaria (12.8% crude protein, 1.0% crude lipid) on growth and body composition of H. discus hannai. Experimental diets were formulated to contain 34.1% crude protein and 7.5% crude lipid. The abalone fed the experimental formulated diet and several commercial diets showed better survival and growth rate (Fig. 1) than those fed Unclaria. Similar results for H. discus hannai and H. fulgens have also been observed in other studies (Nie et al. 1986, Viana et al. 1993). For further expansion of abalone farming, use of formulated artificial feeds is desirable to ensure a better growth.

Development of nutritionally balanced and cost-effective feeds is dependent on information on the nutritional requirements and feed utilization of the species. To date, nutrition research on H. discus hannai has identified dietary requirements of protein (Uki et al. 1986a, Mai et al. 1995a), lipids, and essential fatty acids (Uki et al. 1986b, Mai et al. 1995b, Mai et al. 1996), vitamins (Tan & Mai 2001), and minerals (Tan et al. 2001) for normal growth. Other studies have also been conducted to investigate the utilization of dietary sources for protein (Uki et al. 1985, Lee et al. 1998a, Lee et al. 1999a), lipid (Lee & Park 1998), carbohydrate (Lee et al. 1998b), and additives (Lee et al. 1998c, Lee et al. 1999b, Lee et al. 2000, Lira & Lee 2003) in the same species. Based on the nutritional information available, practical feed formulation (Lee 1998) has been studied to improve aquaculture production of H. discus hannai. The results of the research on the utilization of dietary protein, lipid, and carbohydrate in H. discus hannai are reviewed in this study.

PROTEIN

In nutritional studies on the animals, determination of their dietary protein requirement is generally considered as a primary step. Proteins are not only the major constituent of animal's bodies, but also function as enzymes and hormones. Therefore, a continuous supply of proteins with balanced amino acids is required for maintenance and growth of target animal. Without satisfying the protein requirement, adequate growth and health of the animal cannot be ensured. On the other hand, if excessive proteins are provided, some of them are metabolized as energy; thus the most expensive dietary component will not be effectively used. In the study conducted by Uki et al. (1986a) and Mai et al. (1995a) to determine the protein requirements of H. discus hannai, diets containing casein or fish meal as the protein sources were fed to abalone initially weighing 3.5 g and 0.4 g, for 40 days and 100 days, respectively. The research conducted by Uki et al. (1986a) showed that growth of H. discus hannai fed diets containing 20% to 30% crude protein was better. Mai et al. (1995a) estimated that the optimum crude protein level for growth of H. discus hannai was between 25% to 37%. Taylor (1992) and Coote et al. (2000) reported that dietary crude protein requirements of H. kamtschatkana and H. laevigata were 30% and 27%, respectively. H. midae exhibited optimum growth rate when crude protein levels are 36% to 47% in the diets (Britz 1996, Sales et al. 2003). These optimum dietary protein levels for abalone are lower than those for most carnivorous and omnivorous fish and similar to those for several herbivorous fresh water fish, such as common carp and Nile tilapia (NRC, 1993). The reason for the different crude protein requirement between studies, even though the same abalone species were used and the rough requirement ranges reported as compared with other fish, is not clear but may be due to differences in abalone size, feeding trial periods, digestible protein to energy ratios, essential amino acid pattern in the diets, culture surroundings, or statistical analysis methods used in the studies. Differences in leaching rates of nutrients from the diets into water could also have resulted in the differences between the protein requirement studies.

Besides biologic protein requirements, economics, and culture strategy need to be considered in formulating practical feeds. This seems to be of primary importance for abalone farmers who want to grow their abalone to marketable size. In this respect, recent experience suggests that it might be necessary to include more than 20% crude protein in the formulation of the practical feeds for H. discus hannai to obtain good growth (Lee et al. 1998a). Furthermore, the dietary protein level should be higher to compensate essential amino acid imbalance (NRC 1993, Sales & Britz 2001) when high quality protein in diets is replaced by protein from byproducts without fine tuning of amino acid balance and poor digestibility of those substitutes. The formulation of artificial diets should be based on the availability of the nutrients in the ingredients used and the animal's requirements for those nutrients. Among dietary ingredients, the protein source is important, because protein is much more expensive than lipid or carbohydrate, and the growth of animal could be more influenced by availability of dietary protein sources. Thus, high-quality proteins are necessary for a good artificial feed for abalone. Uki et al. (1985) reported that casein was the best protein source for use in H. discus hannai diets. In addition, results conducted by Viana et al. (1993) showed that each of casein and fish meal was equally good protein source for growth of H. fulgens. Britz (1996) reported that low-temperature-processed fish meal and Spirulina were the most suitable candidates for primary protein sources in formulated diets for H. midae. These protein sources are expensive to use in the practical feeds, thus partial or total replacement of casein or fish meal by low-cost practical alternate protein sources would be promising for the economic advantage. An 18-wk growth trial was conducted by Lee et al. (1998a) to evaluate the practical dietary protein sources for juvenile H. discus hannai. Three replicate groups of H. discus hannai averaging 110 [+ or -] 7 nag were fed one of ten diets containing casein, white fish meal (WFM), meat meal (MM), feather meal (FM), blood meal (BM), soybean meal (SM), corn gluten meal (CGM), cotton seed meal (CSM), Undaria powder (UP), or wheat flour (WF) as a dietary protein source. In addition, growth of abalone fed these dietary protein sources was compared with abalone fed macroalgae such as Undaria or Laminaria. Weight gain (Fig. 2) of H. discus hannai fed the diets containing casein, WFM, SM, CSM, or UP was significantly higher than those of abalone fed the other diets. The weight gain of abalone fed the FM, BM, CGM, or macroalgae diets was significantly lower than that of abalone fed the other diets. Lee et al. (1999a) also investigated the utilization of wheat germ meal (WGM) as a protein source replacing fish meal and soybean meal in formulated diet for juvenile H. discus hannai. Survival, weight gain, and shell growth of the abalone fed the diets containing 10% to 30% WGM were not different to those of abalone fed the control diet. It is concluded that WFM, SM, CSM, UP, and WGM can be used as good sources of protein in formulated diet for H. discus hannai.

It was suggested that a diet containing plant protein sources in combination with animal protein sources produced a better growth of abalone (H. fulgens and H. asinina) compared with diets containing plant protein sources alone (Guzman & Viana 1998, Bautista-Teruel et al. 2003). The good growth of abalone fed diets containing combination of plant and animal protein sources could have partly been attributed to the fact that some limiting essential amino acids in plant protein sources might be compensated by animal protein sources. Lee (1998) and Kim et al. (1998) also reported the efficiency of the use of combination of plant and animal protein sources in the practical diets for H. discus hannai.

LIPID

Dietary lipids play important roles in providing energy, essential fatty acid (EFA), and fat-soluble nutrients for normal growth of animal. Carnivorous fish have limited ability to use carbohydrates as an energy source, but can efficiently use dietary lipid as high as 10% to 25%. In comparison, almost all the herbivorous fish including abalone can efficiently use carbohydrates as an energy source, but cannot use high lipid levels (Lee et al. 1998b). Mat et al. (1995b) reported an optimum lipid requirement in a formulated diet for H. discus hannai to be about 3% to 7%.

EFA requirements in fish differ among species (NRC 1993). Fresh water fish require 18:3n-3 and/or 18:2n-6, whereas marine fish require n-3 highly unsaturated fatty acids (n-3HUFA) such as EPA and DHA. The EFA requirement of H. discus hannai has been studied by Uki et al. (1986b). The study showed that H. discus hannai requires n-3 and n-6 HUFA as EFA, and the n-3HUFA requirement was about 1% in a diet containing 5% lipid. Experiments were carried out by Lee and Park (1998) to evaluate the effects of lipid source in formulated diets on the growth and body composition of juvenile H. discus hannai. Three replicate groups of H. discus hannai averaging 151 [+ or -] 5 mg were fed the casein-based diets containing 5% squid liver oil (SO), 5% corn oil (CO), 5% beef tallow (BY), 2.5% SO + 2.5% CO, and 2.5% SO + 2.5% BT for 20 wk. Weight gain (Fig. 3) and shell growth of H. discus hannai fed the diets containing SO, SO + CO or SO + BT were significantly higher than those of abalone fed the diets containing CO or BT alone. These data indicate that SO is a good dietary lipid source for juvenile H. discus hannai. Oil supplement in diets is not necessary when fish meal is used as the main protein source (Lee & Park 1998). Considering the results (Uki et al. 1986b, Mat et al. 1995b, Lee & Park 1998), 2% to 5% crude lipid may be recommended for practical H. discus hannai diets, when EFA requirement is satisfied with marine fish oils rich in n-3HUFA.

CARBOHYDRATE

Feed costs in aquaculture can be minimized by optimal use of low-cost energy sources such as carbohydrates. The ability of fish to use different carbohydrate sources and levels differs among species (Wilson, 1994). The utilization of dietary carbohydrates in aquatic animals seems to be related to their digestive and metabolic systems adapted to different aquatic environments and to dietary carbohydrate level and complexity (Walton & Cowey 1982). Carbohydrate utilization by most carnivorous fish is lower than that of herbivorous and omnivorous fish. The growth of fish is reduced when fed carbohydrate-deficient diets because other nutrients such as protein are catabolized for energy and to provide metabolic intermediates for the synthesis of other biologically important compounds (Wilson 1994). A 20-wk growth trial was conducted by Lee et al. (1998b) to investigate the utilization of carbohydrate sources by juvenile H. discus hannai. Four replicate groups of H. discus hannai averaging 125 [+ or -] 1.1 mg were fed one of eight diets containing 24.2% wheat flour (WF), 20% dextrin (DEX), 20% sucrose (SUC), 10% s-potato starch + 10% [beta]-potato starch (ab-S), 15% [alpha]-potato starch (a-S15), 20% [alpha]-potato starch (a-S20), 25% [alpha]-potato starch (a-S25), or mixture of carbohydrates (MIX) with practical ingredients such as soybean meal, corn gluten meal, cotton seed meal, and wheat flour. These formulated diets were compared against Undaria or Laminaria. Survival, weight gain (Fig. 4) and shell growth of H. discus hannai were not significantly affected by the different dietary carbohydrate sources, although those fed the a-S15 diet had slightly lower weight gain than those fed the other formulated diets. H. discus hannai fed Laminaria had the lowest weight gain, followed by those fed the Undaria. These data indicate that H. discus hannai were able to efficiently use the carbohydrate sources used in the study. The lower growth rate of H. discus hannai fed the a-S15 diet may be due to its high lipid content (7.5%) compared with those (3.1% to 5.3%) of other diets. Research on the digestive enzymes of Haltotis spp. has shown that abalone have high protease, amylase, cellulase, and alginase, but low lipases (Oshima 1931, McLean 1970, Cho et al. 1983, Nakagawa & Nagayama 1988, Gomez-Pinchetti & Garcia-Reina 1993, Britz et al. 1994). These investigations indicate that H. discus hannai use carbohydrate more efficiently than lipids as an energy source.

Figure 1. Weight gain [(final weight-initial weight) x 100/initial
weight] of Haliotis discus hannai fed the experimental diet, commercial
diets and Undaria for 17 wk (data from Lee et al. 1997).

Diets          Weight gain (%)

Exp. diet            233
Com. diet            239
Com. diet-2          236
Undaria              172

 Note: Table made from bar graph.

Figure 2. Weight gain [(final weight-initial weight) x 100/initial
weight] of Haliotis discus hannai fed the diets containing various
protein sources and macroalgae (Undaria and Laminaria) for 17 wk. Data
with different letters were reported as significantly different using
ANOVA and a multiple range test with P < 0.05 (data from Lee et al.
1998a).

Protein sources     Weight
                   gain (%)

Casein             494    e
WFM                557    e
MM                 303    c
FM                 135    ab
BM                 78     a
SM                 554    e
CGM                155    ab
CSM                503    e
UP                 495    e
WF                 396    d
Undaria            221    b
Laminaria          172    b

Note: Table made from bar graph.

Figure 3. Weight gain [(final weight-initial weight) x 100/initial
weight] of Haliotis discus hannai fed the diets containing various
lipid sources for 20 wk. Data with different letters were reported as
significantly different using ANOVA and a multiple range test with P <
0.05 (data from Lee & Park 1998).

Lipid sources     Weight
                 gain (%)

SLO              418    b
CO               254    a
BT               273    a
SLO+CO           417    b
SLO+BT           349    b

Note: Table made from bar graph.

Figure 4. Weight gain [(final weight-initial weight) x 100/initial
weight] of Haliotis discus hannai fed the diets containing various
carbohydrate sources and macroalgae (Undaria and Laminaria) for 20 wk.
Data with different letters were reported as significantly different
using ANOVA and a multiple range test with P < 0.05 (data from Lee &
Park 1998).

Carbohydrate sources     Weight
                        gain (%)

WF                      224    cd
DEX                     228    cd
SUC                     249    d
ab-S                    250    d
a-S15                   196    bc
a-S20                   229    cd
a-S25                   229    cd
MX                      228    cd
Undaria                 157    b
Laminaria               111    a

Note: Table made from bar graph.

LITERATURE CITED

Bautista-Teruel, M. N., A. C. Fermin & S. S. Koshio. 2003. Diet development and evaluation for juvenile abalone, Haliotis asinina: animal and plant protein sources. Aquaculture 219:645-653.

Britz, P. J. 1996. The suitability of selected protein sources for inclusion in formulated diets for the South African abalone Haliotis midae. Aquaculture 140:63-73.

Britz, P. J., T. Hecht, I. Knauer & M. G. Dixon. 1994. The development of an artificial feed for abalone farming. South Afr. J. Sci. 90:7-8.

Cho, D. M., J. H. Pyeun, D. S. Byun & C. Y. Kim. 1983. Proteolytic activity of the crude enzyme extracted from the digestive tract of marine gastropods. J. Korean Fish. Soc. 16:216-224.

Coote, T. A., P. W. Hone, R. J. Van Barneveld & G. T. Maguire. 2000. Optimal protein level in a semipurified diet for juvenile greenlip Haliotis laevigatu. Aquaculture Nutrition 6:213-220.

Gomez-Pinchetti, J. L. & G. Garcia-Reina. 1993. Enzymes from marine phycophages that degrade cell walls of seaweeds. Mor. Biol. 116:553-558.

Guzman, J. M. & M. T. Viana. 1998. Growth of abalone Haliotis fulgens fed diets with and without fish meal, compared to a commercial diet. Aquaculture 136:313-321.

Kikuchi, S. & N. Uki. 1974. Technical study on artificial spawning of abalone, genus Huliotis I. Relation between water temperature and advancing sexual maturity of Haliotis discus hannui Ino. Bull. Tohoku Reg. Fish. Res. Lab. 33:69-78.

Kim, B. H., S.-M. Lee, C. S. Go, J. W. Kim & J. I. Myeong. 1998. Optimum stocking density of juvenile abalone (Haliotis discus hannai) fed formulated diet or macroalgae (Undaria). J. Korean Fish. Soc. 31:869-874.

Lee, S.-M. 1998. Evaluation of economical feed formulations for abalone (Haliotis discus hannai). J. Aquacult. 11:159-166.

Lee, S.-M. & H. G. Park. 1998. Evaluation of dietary lipid sources for juvenile abalone (Holiotis discus hannai). J. Aquacult. 11:381-390.

Lee, S.-M., G. A. Lee, I. G. Jeon & S. K. Yoo. 1997. Effects of experimental formulated diets, commercial diet and natural diet on growth and body composition of abalone (Haliotis discus hannai). J. Aquacult. 10:417-424.

Lee, S.-M., S. Y. Yun & S. B. Hut. 1998a. Evaluation of dietary protein sources for abalone (Haliotis discus hannai). J. Aquacult. 11:19-29.

Lee, S.-M., S. J. Yun, K. S. Min & S. K. Yoo. 1998b. Evaluation of dietary carbohydrate sources for juvenile abalone (Haliotis discus hannai). J. Aquacult. 11:133-140.

Lee, S.-M., Y. S. Lira, Y. B. Moon, S. K. Yoo & S. Rho. 1998c. Effects of supplemental macroalgae and Spirulina in the diets on growth performance in juvenile abalone (Haliotis discus hannai). J. Aquacult. 11: 31-38.

Lee, S.-M., J. K. Lee, J. H. Lee & Y. S. Lira. 1999a. Evaluation of wheat germ meal as a protein source of formulated diet for juvenile abalone (Haliotis discus hannai). J. Aquacult. 12:317-322.

Lee, S.-M., Y. S. Lim, J. K. Lee, S. R. Park, J. I. Myeong & Y. J. Park. 1999b. Effects of supplemental squid meal, attractant, herb or lecithin in the formulated diets on growth performance in juvenile abalone (Haliotis discus hannai). J. Korean Fish. Soc. 32:290 294.

Lee, S.-M., D. J. Kim, J. K. Kim, J. K. Lee, J. H. Lee & S. U. Park. 2000. Utilization of supplemental Kluyveromyces fragilis, Candida utilis, Saccharomyces cerevisiae or brewer's yeast in the formulated diets for juvenile abalone (Haliotis discus hannai). J. Aquacult. 13:55-62.

Lim, T.-J. & S.-M. Lee. 2003. Effect of dietary pigment sources on the growth and shell color of abalone, Haliotis discus hannai. J. Korean Fish. Soc. 36:601-605.

Mai, K., J. P. Mercer & J. Donlon. 1995a. Comparative studies on the nutrition of two species of abalone, Haliotis mberculam L and Haliotis discus hannai Ino. IV. Optimum dietary protein level for growth. Aquaculture 136:165-180.

Mai, K., J. P. Mercer & J. Donlon. 1995b. Comparative studies on the nutrition of two species of abalone, Haliotis tuberculata L and Haliotis discus hannai Ino. II. Response of abalone to various levels of dietary lipid. Aquaculture 134:65-80.

Mai, K., J.P. Mercer & J. Donlon. 1996. Comparative studies on the nutrition of two species of abalone, Haliotis tuberculata L and Haliotis discus hannai Ino. V. The role of polyunsaturated fatty acids of macroalgae in abalone nutrition. Aquaculture 139:77-89.

McLean, N. 1970. Digestion in Haliotis rufescens Swainson (Gastropoda: prosobranchia). J. Exp. Zool. 173:303-318.

Nakagawa, T. & F. Nagayama. t988. Distribution of glycosidase activities in marine invertebrates. J. Tokyo Univ. Fish. 75:229-234.

Nie, Z. Q., Z. Q. Wang & J. p. Yah. 1986. Experiments on preparing of formulated teed and feeding efficiency of young abalone, Haliotis discus hannai Ino. Mar. Fish. Res. 7:53-64.

National Research Council (NRC). 1993. Nutrient requirements of fish. Washington DC: National Academy Press. pp. 114.

Oshima, K. 1931. Digestive enzymes appeared in abalone viscera. J. Agric. Chem. 7:328-331.

Sales, J. & P. J. Britz. 2001. Evaluation of different markers to determine apparent nutrient digestibility coefficients of feed ingredients for South African abalone (Hal iotis midae L.). Aquaculture 202:113-129.

Sales, J., P. J. Truter & P. J. Britz. 2003. Optimum dietary crude protein level for growth in South African abalone (Haliotis midae L.). Aquaculture Nutrition 9:85-89.

Tan, B. & K. Mai. 2001. Zinc methionine and zinc sulfate as sources of dietary zinc for juvenile abalone, Haliotis discus hannai Ino. Aquaculture 198:141-158.

Tan, B., K. Mai & Z. Liufu. 2001. Response of juvenile abalone, Haliotis discus hannai, to dietary calcium, phosphorus and calcium/phosphorus ratio. Aquaculture 198:141-158.

Taylor, B. 1992. Abalone nutrition: optimum protein levels in artificial diets for Haliotis kamtschatkana. J. Shellfish Res. 11:556.

Uki, N. & S. Kikuchi. 1982. Technical study on artificial spawning of abalone, genus Haliotis VIII. Characteristics of spawning behavior of H. discus hannai induced by ultraviolet irradiation stimulus. Bull. Tohoku Reg. Fish. Res. Lab. 44:83-90.

Uki, N., A. Kemuyama & T. Watanabe. 1985. Nutritional evaluation of several protein sources in diets for abalone, Haliotis discus hannai. Bull. Jim. Soc. Sci. Fish. 51:1835-1839.

Uki, N., A. Kemuyama & T. Watanabe. 1986a. Optimum protein level in diets for abalone. Bull. Jpn. Soc. Sci. Fish. 52:1005-1012.

Uki, N., M. Sugiura & T. Watanabe. 1986b. Requirement of essential fatty acids in the abalone, Huliotis discus hannai. Bull. Jpn. Soc. Sci. Fish. 52:1013-1026.

Viana, M. T., L. M. Lopez & A. Salas. 1993. Diet development for juvenile abalone Haliotis Jidgens. Evaluation of two artificial diets and macroalgae. Aquaculture 117:149-156.

Walton, M. J. & C. B. Cowey. 1982. Aspects of intermediary metabolism in fish. Comp. Biochem. Physiol. 73B:59-79.

Wilson, R. P. 1994. Utilization of dietary carbohydrate by fish. Aquaculture 124:67-80.

SANG-MIN LEE

Faculty of Marine Bioscience and Technology, Kangnung National University, Gangneung 210-702, Korea

E-mail: [e-mail]