The Evaluation of Air-Dried Whole Krill Meal as a Dietary Protein Supplement for Juvenile Chinook Salmon (Oncorhynchus tshawytscha)

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The Evaluation of Air-Dried Whole Krill Meal as a Dietary Protein Supplement for Juvenile Chinook Salmon (Oncorhynchus tshawytscha)

.

J.S. Anderson, N.L. Richardson, D.A. Higgs and B.S. Dosanjh

Department of Fisheries and Oceans Science Branch, Pacific Region West Vancouver Laboratory 4160 Marine Drive West Vancouver, B.C. V7V 1N6

JUNj lGI99t

1997

Canadian Technical Report of Fisheries and Aquatic Sciences 2148

1+1

Fisheries and Oceans

Peches et Ocean s

Canada

Canadian Technical Report of Fisheries and Aquatic Sciences Technical reports contain scientific and technical information that contributes to existing knowledge but which is not normally appropriate for primary literature. Technical reports are directed primarily toward a worldwide audience and have an international distribution. No restriction is placed on subject matter and the series reflects the broad interests and policies of the Department of Fisheries and Oceans, namely, fisheries and aquatic sciences. Technical reports may be cited as full publications. The correct citation appears above the abstract of each report. Each report is abstracted in Aquatic Sciences and Fisheries Abstracts and indexed in the Department's annual index to scientific and technical publications. Numbers 1-456 in this series were issued as Technical Reports of the Fisheries Research Board of Canada. Numbers 457-714 were issued as Department of the Environment, Fisheries and Marine Service, Research and Development Directorate Technical Reports. Numbers 715-924 were issued as Department of Fisheries and the Environment, Fisheries and Marine Service Technical Reports. The current series name was changed with report number 925. Technical reports are produced regionally but are numbered nationally. Requests for individual reports will be filled by the issuing establishment listed on the front cover and title page. Out-of-stock reports will be supplied for a fee by commercial agents.

Rapport technique canadien des sciences halieutiques et aquatiques Les rapports techniques contiennent des renseignements scientifiques et techniques qui constituent une contribution aux connaissances actuelles, mais qui ne sont pas normalement appropries pour la publication dans un journal scientifique. Les rapports techniques sont destines essentiellement a un public international et ils sont distribues a cet echelon. 11 n'y a aucune restriction quant au sujet; de fait, la serie reflete la vaste gamme des interets et des politiques du ministere des Peches et des Oceans, c'est-A-dire les sciences halieutiques et aquatiques. Les rapports techniques peuvent etre cites comme des publications completes. Le titre exact parait au-dessus du résumé de chaque rapport. Les rapports techniques sont résumés dans la revue Résumés des sciences aquatiques et halieutiques, et ils sont classes dans l'index annual des publications scientifiques et techniques du Ministere. Les numeros 1 a 456 de cette serie ont ete publies a titre de rapports techniques de ]'Office des recherches sur les pecheries du Canada. Les numeros 457 a 714 sont parus titre de rapports techniques de la Direction generale de la recherche et du developpement, Service des peches et de la mer, ministere de l'Environnement. Les numeros 715 a 924 ont ete publies a titre de rapports techniques du Service des peches et de la mer, ministere des Peches et de l'Environnement. Le nom actuel de la serie a ete etabli lors de la parution du numero 925. Les rapports techniques sont produits a ]'echelon regional, mais numerotes ]'echelon national. Les demandes de rapports seront satisfaites par l'etablissement auteur dont le nom figure sur la couverture et la page du titre. Les rapports epuises seront fournis contre retribution par des agents commerciaux.

Canadian Technical Report of Fisheries and Aquatic Sciences 2148

1997

THE EVALUATION OF AIR-DRIED WHOLE KRILL MEAL AS A DIETARY PROTEIN SUPPLEMENT FOR JUVENILE CHINOOK SALMON (ONCORHYNCHUS TSHAWYTSCHA)

by

1

J.S. Anderson , N.L. Richardson

2

,

D.A. Higgs and B.S. Dosanjh

Department of Fisheries and Oceans Science Branch, Pacific Region West Vancouver Laboratory 4160 Marine Drive West Vancouver, B.C. V7V 1N6

1

Department of Animal Science, University of British Columbia, 208 - 2357 Main Mall, Vancouver, B.C. V6T 1Z4 2

NLR Consulting, 483 Stewart Street, Comox, B.C. V9M 2X5

- ii -

(c) Minister of Supply and Services Canada 1997 Cat. No. Fs97-6/2148E ISSN 0706-6457

Correct citation for this publication: Anderson, J.S., N.L. Richardson, D.A. Higgs and B.S. Dosanjh. 1997. The evaluation of air-dried whole krill meal as a dietary protein supplement for juvenile chinook salmon (Oncorhynchus tshawytscha). Can. Tech. Rep. Fish. Aquat. Sci. 2148: 12 p.

- iii -

TABLE OF CONTENTS Page ABSTRACT .................................................................................................................... iv RESUME ........................................................................................................................ iv INTRODUCTION ............................................................................................................. 1 MATERIALS AND METHODS ......................................................................................... 3 EXPERIMENTAL FISH AND CULTURE CONDITIONS ....................................... 3 EXPERIMENTAL DIETS ....................................................................................... 3 FEED PRESENTATION ........................................................................................ 3 EXPERIMENTAL PROCEDURES AND SAMPLING ........................................... .4 STATISTICAL ANALYSES ................................................................................... 4 RESULTS AND DISCUSSION ........................................................................................ 5 CONCLUSIONS .............................................................................................................. 6 ACKNOWLEDGEMENTS ................................................................................................ 6 REFERENCES ................................................................................................................ 7 TABLES ........................................................................................................................... 9

- lV ABSTRACT

Anderson, J.S., N.L. Richardson, D.A. Higgs and B.S. Dosanjh. 1997. The evaluation of air-dried whole krill meal as a dietary protein supplement for juvenile chinook salmon (Oncorhynchus tshawytscha). Can. Tech. Rep. Fish. Aquat. Sci. 2148: 12 p. A study was conducted to determine the effects of different dietary concentrations of air-dried whole krill meal on the growth of juvenile chinook salmon. The fish were fed daily to satiation for 56 days one of three test diets containing 50, 150, or 250 g air-dried krill meal kg-1 dietary dry matter, as replacements for herring meal in a basal diet. The Oregon moist pellet (OMP) diet was used as a reference control. All groups fed the krill meal diets had significantly higher weight gains than those fed OMP. Similarly, fish fed the diet containing 250 g of krill meal kg- 1 were significantly larger than either the fish fed the diets containing 50 or 150 g of krill meal 1 kg" dry diet. Feed intakes, feed conversions, specific growth rates, and percent survivals were not significantly different among fish fed the various diets. The protein efficiency ratios were significantly lower for the OMP fed fish than for those fed the diet containing 250 g of krill meal kg- 1 . It is concluded that fish fed diets containing air-dried whole krill meal grow better than those fed OMP and that inclusion of 250 g of air-dried krill meal kg- 1 of the dry matter provides a distinct advantage over lower inclusion rates.

RESUME

Anderson, J.S., N.L. Richardson, D.A. Higgs and B.S. Dosanjh. 1997. The evaluation of air-dried whole krill meal as a dietary protein supplement for juvenile chinook salmon (Oncorhynchus tshawytscha). Can. Tech. Rep. Fish. Aquat. Sci. 2148: 12 p. Nous avons effectue une etude en vue de determiner les effets de differentes concentrations de farine de krill entier seche a I' air sur Ia croissance des quinnats juveniles. Pendant 56 jours, on a administre a satiate aux poissons l'un des trois aliments testes, qui contenaient 50, 150 ou 250 g de farine de krill entier seche I' air par kg d'aliment sec, pour remplacer Ia farine de hareng dans un regime de base. Le regime a base de granules humides Oregon (OMP) a servi de temoin. Tousles groupes nourris avec Ia farine de krill ont connu une prise de poids nettement superieure a celle des groupes nourris a I'OMP. De meme, les poissons nourris a !'aliment sec contenant 250 g de farine de krill par kg etaient nettement plus gros que ceux qui recevaient I' aliment sec contenant 50 ou 150 g de farine de krill. L'absorption de nourriture, Ia conversion energetique, le taux de croissance specifique et le taux de survie ne differaient pas de fac;on significative entre les groupes. Les coefficients d'efficacite proteique etaient nettement inferieurs chez les saumons nourris a I'OMP par

a

- v -

a

a

rapport ceux nourris I' aliment contenant 250 g de farine de krill par kg. Nous concluons que les saumons nourris avec des aliments contenant de Ia farine de krill entier seche a l'air grossissent plus que ceux qui reyoivent I'OMP, et que le melange de 250 g de farine de krill seche a l'air par kg de matiere seche donne un resultat nettement meilleur que les concentrations plus faibles de farine de krill.·

INTRODUCTION Feed comprises 40%-50% of the total operating costs of both salmon hatcheries and farms in British Columbia. For this reason, considerable research has been undertaken to develop practical diets for the aquaculture and resource enhancement industries. Commercial salmon farms typically use dry diets. However, hatcheries, particularly government hatcheries in British Columbia, are still using moist (250-300 g of moisture kg- 1 diet) and semi-moist ( 150 g of moisture kg- 1 diet) diets that are imported from the United States. While these feeds have proven to be effective in promoting good fish growth and health, they are very expensive and require special handling conditions and storage facilities. Since the hatchery stage is such a crucial phase in the salmon's life history, hatcheries are prepared to pay the higher prices for moist and semi-moist feeds. Nevertheless, the opportunity and resources exist to develop one or more costeffective dry diets that will meet the needs of the salmon hatchery program. The most effective way to economize on the price of a feed is to reduce the cost associated with supplying dietary protein. Protein is the largest single nutrient in a complete salmon feed, and can represent up to 66% of the total cost (Higgs et al., 1995a). Premium quality fish meals are the major feedstuffs used to supply protein in salmonid diets. Several studies have been conducted to find or develop alternate sources of protein for salmonid diets (Higgs et al., 1979; Fowler, 1980; Hilton and Slinger, 1986; Higgs et al., 1988; Tacon, 1994). The majority of this work has investigated the potential of plant proteins as alternatives to fish meal. Plant protein sources such as cottonseed, soybean, and canola meal are less expensive on a cost per protein basis than fish meal. However, plant protein feedstuffs contain unique anti-nutritional factors such as gossypol (cottonseed) and glucosinolates (canola). Moreover, common deleterious components such as phytic acid are also present in most plant protein sources. Collectively, these antinutrients limit the levels at which these feedstuffs can be included into fish feeds (Higgs et al., 1995a,b). Other animal protein products, such as poultry by-product meal, blood flour, and hydrolysed feather meal are also commonly used in commercial salmonid feeds (Asgard, 1988; Tacon, 1994). Krill is an example of a potential feedstuff which has been tested to a limited extent in diets for salmonids (Higgs et al., 1985; Storebakken, 1988). Krill are marine, pelagic crustaceans that belong to the order Euphausiacea in which 85 species have been recorded (Storebakken, 1988). Krill species, particularly the Antarctic krill (Euphausia superba) and Pacific krill (f. pacifica) are widely recognized as being highly nutritious and extremely palatable feedstuffs for salmonids (Storebakken, 1988). In addition to their excellent essential amino acid profile, krill contain substantial amounts of essential fatty acids of the omega-3 family and carotenoid pigments. Thus, krill species are very attractive feed ingredients for salmonids (Storebakken, 1988).

-2 Several experiments have been undertaken to assess krill meal as a partial or total replacement of fish meal in the diets of rainbow trout (Oncorhynchus mykiss). In many cases, replacement of all of the fish meal has resulted in reduced growth and feed conversion efficiency (Beck et al., 1977 as cited in Storebakken 1988; Gamygin et al., 1978 as cited in Storebakken, 1988; Koops et al., 1979). In other instances, krill meal has been shown to be interchangeable with fish meal (VensCapel and Horstmann, 1978 as cited in Storebakken, 1988; Papuktchieva et at., 1981 as cited by Storebakken 1988). In chum salmon (Oncorhynchus keta) Murai et at. (1980) reported that the dietary concentration of krill meal (100 to 500 g kg- 1 by replacement of white fish meal in a basal diet) was inversely related to the growth rates and feed efficiencies of the fish. In contrast, Akiyama et al. (1984) noted that chum salmon fed a diet supplemented with 50 g krill meal kg- 1 showed improved growth compared with the fish fed a control diet based on white fish meal. The dissimilar findings between the two studies could be due to the fact that Akiyama et al. ( 1984) used a krill meal from a product that had been prepared for human consumption, whereas Murai et al. ( 1980) used a commercially available krill meal that was likely of lower quality. Other work has investigated the potential for using Antarctic krill meal, either whole body or non-muscle, in diets for red sea bream (Chrysophyrus major), Japanese eel (Anguilla japonica) or grey mullet (Mugil cephalus) (AIIahpichay and Shimizu, 1984). These studies found that 50 g of non-muscle krill meal kg- 1 diet was equivalent in nutritive value to 200 g of whole body krill meal kg- 1 diet in the various fish species. The reason(s) for the differences in the performance of the fish fed the different sources of meal was not elucidated. Currently, krill is available as frozen whole krill, freeze-dried whole krill and dried krill meal powder (whole or non-muscle). Due to the perishability of raw krill, the dry krill meals are preferred products for inclusion in formulated feeds. Because krill meal is expensive, it is generally restricted to the starter diets, where it constitutes less than 7% of the total diet (as opposed to herring meal which is greater than 50%). If it were possible to obtain a source of krill meal that is of high nutritive value, but of similar cost to fish meal, it may be feasible to use significantly higher levels of this product in starter diets for salmon. This study had two goals. The first, was to compare the nutritive value of a low temperature, air-dried whole euphausiid meal to that of steam-dried whole herring meal for juvenile fall chinook salmon (Oncorhynchus tshawytscha). The euphausiid product was prepared by a novel, cost effective procedure. The second, was to assess whether the performance of chinook fed open formula dry diets would be equivalent to or better than that of fish fed OMP, a diet imported from the United States and presently used in federal salmon hatcheries in British Columbia.

-3MATERIALS AND METHODS EXPERIMENTAL FISH AND CULTURE CONDITIONS In April 1994, juvenile chinook salmon from the Robertson Creek hatchery (Port Alberni, British Columbia) were selected for uniform weight (2.83 ± 0.47 g (sd)). Subsequently, the fish were distributed randomly into eight 3 m diameter outdoor fibreglass tanks so that each tank contained approximately 5000 fish (1.8 kg m- 3 ). Each tank was supplied with freshwater from Great Central Lake and water flow rates were varied between 40 and 60 L min- 1 , in accordance with the increase in fish biomass during the experiment. Water temperatures were recorded twice daily and average temperature during the experimental period was 13.4oC (13.QoC to 13.7oC).

EXPERIMENTAL DIETS Air-dried whole krill meal was obtained from Specialty Marine Products Ltd. (Vancouver, BC). The meal was reground to pass through a 1.5 mm mesh screen and thereafter it was stabilized with 250 mg of ethoxyquin kg- 1 and stored at -2Q.QoC until used. Three isocaloric (18 MJ estimated metabolizable energy kg- 1 dietary dry matter (OM)) and isonitrogenous (544 g crude protein kg- 1 OM) diets were prepared by steam-pelleting (Table 1) at the West Vancouver Laboratory using equipment and procedures similar to those described by Higgs et al. (1979). The levels of krill meal in the test diets were 50, 150, and 250 g kg- 1 on a dry weight basis. This resulted in krill furnishing 7.4%, 22.1 %, and 36.8% of dietary protein, respectively. Three different pellet sizes were manufactured to match fish size - a #2 crumble ( 1.2 mm particle (3/64")), a 1.6 mm ( 1/16") pellet, and a 2.0 mm (5/64") pellet. Oregon moist pellets {OMP) (Bioproducts Inc., Warrenton, Oregon) (Table 2), which is commonly used at the Robertson Creek hatchery, served as a commercial control diet. Pellet sizes for OMP were 1.6 mm (1 /16"), 2.4 mm (3/32"), and 3.2 mm (1 /8"). The pellet sizes for OMP differed from those of the dry diets because salmonids typically accept larger sizes of soft textured moist pellets as compared to the harder dry pelleted diets.

FEED PRESENTATION Each diet was randomly assigned to duplicate tanks of fish. The fish were fed by hand to satiation twice' daily, seven days a week, for 56 days. On the 13th day of each of the two-week periods, the fish were fed only once in the morning. This provided a 24 hour starvation period and adequate evacuation of gut contents prior to the fish being weighed. Records of daily feed consumption were maintained and all diets were stored in a freezer after the last feeding of each day.

-4 The OMP containers were placed in a freezer between each feeding. After each two-week period, the dietary particle size was adjusted in relation to fish size as recommended by Fowler and Burrows (1971 ). To avoid fines in the water and also to improve feed efficiency, all diets were screened prior to being ·fed. EXPERIMENTAL PROCEDURES AND SAMPLING On day 0 of the experiment and every 14 days thereafter, three random samples of fish were removed from each tank and then a composite sample of 60 fish tank- 1 was randomly selected. The fish were then anaesthetized with an equal mixture of MS 222 and sodium bicarbonate to provide a final concentration of 50 mg of MS 222 r 1 of water. The fish were individually weighed to the nearest 0. 1 gram and fork lengths were measured to the nearest 0.1 centimetre. On day 0 and day 56 of the experiment, an additional 20 fish tank- 1 were removed, killed, and frozen at -20oC pending proximate analysis. Mortalities and moribund fish were removed daily and recorded. Any abnormalities such as scoliosis or clubbed gills were also recorded. Specific growth rate (SGR) was determined as % increase in body weight day- 1 (Brett, 1979). Feed intake was expressed as a percentage of body weight day- 1 over the experimental period by using the following formula: dry feed intake (g fish- 1 day- 1) x 100 x (antilog((logWt + 1

+

logWt) x 0.5)r 1

where, logWt and logWt + 1 are the average log wet weights (g) at the start (t) and the end (t + 1) of the period. Feed conversion and protein efficiency ratios (PER) were calculated as dry feed intake (g) x wet weight gain (gr 1 and wet weight gain x protein intake (gr 1 , respectively. The proximate compositions of the diets and whole-fish carcasses were determined by using the methods described by Higgs et al. ( 1979). All analyses were performed in duplicate. Percent nitrogen was multiplied by 6.25 to obtain percent crude protein. STATISTICAL ANAlYSES Data were tested for homogeneity of variance using Bartlett's test. If homogeneity was not met a square root transformation was used. Data were analysed by one-way analysis of variance. When a significant effect of diet was detected by analysis of variance, further differences among means were determined by using the student Newman-Keuls multiple comparison procedure (Kieinbaum et al., 1988). All tests were evaluated at P = 0.05. The pooled standard deviation was determined by using the error mean square from the

\ -5 analysis of variance for the estimate of sample variance. Statistical analyses were performed using Systat (Ver. 4.0, Systat, Inc., 1800 Sherman, Ave., Evanston, IL). RESULTS AND DISCUSSION Four different batches of each of the experimental diets were prepared throughout the experiment and their proximate compositions are presented in Table 3. The proximate compositions were similar between batches of each diet. The protein level in OMP was aprroximately 3% higher than the protein level in the dry diets. (580 versus 547 g kg- ). Also, OMP contained approximately 1% more lipid in the OM than noted in the experimental dry diets. The OMP diet also contained one third less ash (89 versus 134 g kg- 1 ) in the OM than the diets containing krill meal. The higher ash contents found in the latter diets can be accounted for by the differences in supplemental levels of minerals and the higher amounts of fish meal that were employed in the test dry diets. The growth performance and percent survival of the fish fed the experimental and control diets are shown in Table 4. The initial mean weights of the fish were not different and this was also true after 14 days of feeding. After 28 days, the fish fed OMP were significantly smaller than any of the fish fed the diets containing krill meal and tbis trend continued until the end of the experiment. After 56 days, the fish fed diet 3 (contained 250 g air-dried krill meal kg- OM), were significantly heavier than those fed the diets containing either 50 or 150 g krill meal kg- 1 OM. SGR values (Table 4) were not significantly different among the various treatment groups, although the fish fed the diet containing the highest level of krill meal had the fastest rate of growth, whereas the fish fed the OMP diet had the lowest. The reason for the lack of significant differences for SGR is due to the loss of power in the statistical tests (Searcy-Bernal, 1994). This was, in part due to insufficient numbers of replicate groups per diet treatment. In the case of SGR, the power of the test was found to be 0.3 or there was a 70% chance of not detecting a diet effect for this parameter. All experimental fish appeared healthy and showed no visible signs of disease. Percent survivals were not significantly different among the groups (Table 4). Several of the moribund fish were observed to have clubbed gills. This could have been a consequence of overcrowding since biomass greatly increased during the experiment. Water flows into the tanks were equally increased during the study to help compensate for increased fish biomass and to help maintain good water quality. There were no significant differences in either feed intakes (power = 0.20) or feed to gain ratios (power = 0.35) among the treatment groups (Table 5). All

- 6diets were readily accepted by the fish. Values for PER however, were lowest (poorest) for the OMP fish and highest for the fish fed the diet containing 250 g krill meal kg- 1. This finding may have been due to the slightly higher protein to lipid ratio in OMP than observed in the experimental diets (2.91 versus 2.84). In this situation, slightly poorer protein utilization would be anticipated (Higgs et al., 1995a). There were no differences in whole-body protein or in any of the other proximate constituents of the fish (Table 6). The power of the various analyses of variances dealing with whole-body proximate composition ranged from approximately 0.12 to 0.50. The results of this study support those of Pfeffer and Becker (1977 as cited by Storebakken, 1988), Jahn et al. (1978 as cited by Storebakken, 1988), Koops et al. (1979), and Akiyama et al. (1984), who found that partial replacement of the fish meal in salmonid diets with krill meal improved fish performance

CONCLUSIONS

Our findings suggest that juvenile chinook salmon fed an experimental openformula dry diet containing 250 g air-dried whole krill meal kg- 1 DM will grow faster than those fed imported OMP, one of the standard hatchery diets. Hence, chinook smolts of larger size could be released into the ocean and this in turn would likely improve their ocean survival (Higgs et al., 1995a). It remains to be determined whether the use of air-dried krill meal in starter diets for salmon is economically viable. Also, the merits of using any one of the dry diets, regardless of krill meal concentration in place of OMP should be assessed. Such assessment should involve other species of juvenile Pacific salmon and hopefully the findings will facilitate local manufacture of open formula diets.

ACKNOWLEDGEMENTS

We gratefully acknowledge the financial assistance provided by Specialty Marine Products Ltd. Also, we appreciate the help of Dianne Plotnikoff, Carol Cross, Brian Toy and the staff of Robertson Creek Hatchery.

-7REFERENCES

Akiyama, T., T. Murai, Y. Hirasawa and T. Nose. 1984. Supplementation of various meals to fish meal diet for chum salmon fry. Aquaculture, 37: 217222. Allahpichay, I. and C. Shimizu. 1984. Supplemental effect of the whole body krill meal and the non-muscle krill meal of Euphausia superba in fish diet. Bull. Jap. Soc. Sci. Fish., 50: 815-820. Asg~rd, T. 1988. Nutritional value of animal protein sources for salmonids. In: Aquaculture International Congress & Exposition, Congress Proceedings, Sept. 6-9, 1988. Vancouver, Canada. Pp. 411-418.

Brett, J.R. 1979. Environmental factors and growth. In: W.S. Hoar, D.J. Randall and J.R. Brett (eds). Fish Physiology, Vol. 8., Academic Press, New York. Pp. 599-675. Fowler, L.G. 1980. Substitution of soybean and cottonseed products for fish meal in diets fed to chinook and coho salmon. Prog. Fish-Cult., 42: 87-91. Fowler, L.G. and R.E. Burrows. 1971. The Abernathy salmon diet. Prog. FishCult., 33: 67-75. Higgs, D.A., J.S. Macdonald, C.D. Levings and B.S. Dosanjh. 1995a. Nutrition and feeding habits in relation to life history stage. In: C. Groot, L. Margolis and W.C. Clarke (eds), Physiological Ecology of Pacific Salmon. UBC Press, Vancouver. Pp. 159-315. Higgs, D.A. J.R. Markert, M.D. Plotnikoff, J.R. McBride and B.S. Dosanjh. 1985. Development of nutritional and enviromental strategies for maximizing the growth and survival of juvenile pink salmon (Oncorhynchus gorbuscha). Aquaculture, 4 7: 113-130. Higgs, D.A., J.R. McBride, B.S. Dosanjh, W.C. Clarke, C. Archdekin and A.-M. Hammons. 1988. Nutritive value of plant protein sources for fish with special emphasis on canola products. Aquaculture International Congress & Exposition, Congress Proceedings, Sept. 6-9, 1988. Vancouver, Canada. Pp. 427-435. Higgs, D.A., B. S. Dosanjh, A.F. Prendergast, R.M. Beames, R.W. Hardy, W. Riley and G. Deacon. 1995b. Use of rapeseed/canola protein products in finfish diets. In: C.E. Lim and D.J. Sessa (eds), Nutrition and Utilization Technology in Aquaculture. AOCS Press, Champaign, Illinois, Pp. 130-156.

-8Higgs, D.A., J.R. Markert, D.W. MacQuarrie, J.R. McBride, B.S. Dosanjh, C. Nichols and G. Hoskins. 1979. Development of practical dry diets for coho salmon, Oncorhynchus kisutch using poultry-by-product meal, feather meal, soybean meal and rapeseed meal as major protein sources. In: J.E. Halver and K. Tiews (eds), Finfish Nutrition and Fishfeed Technology, Vol. 2. Heenemann GmbH and Co., Berlin. Pp. 191-218. Hilton, J.W. and S.J. Slinger. 1986. Digestibility and utilization of canola meal in practical-type diets for rainbow trout (Salmo gairdneri). Can. J. Fish. Aquat. Sci., 43: 1149-1155. Klienbaum, D.G., L.L. Kupper and K.E. Muller. 1988. Applied Regression Analysis and Other Multivarible Methods. PWS-Kent, Boston, 718 pp. Koops, H., K. Tiews, J. Gropp and H. Beck. 1979. Krill in trout diets. In: J.E. Halver and K. Tiews (eds), Finfish Nutrition and Fishfeed Technology, Vol. 2. Heenemann GmbH and Co., Berlin. Pp. 281-292. Murai, T., I. Yagisawa, Y. Hirasawa, T. Akiyama and T. Nose. 1980. Protein, fat and carbohydrate sources of practical diet for fingerling chum salmon, Oncorhynchus keta. Bull. Natl. Res. lnst. Aquaculture (Japan), 1: 79-86. Searcy-Bernal, R. 1994. Statistical power and aquaculture research. Aquaculture,

127: 371-388. Storebakken, T. 1988. Krill as a potential feed source for salmonids. Aquaculture,

70: 193-205. Tacon, A.G.J. 1994. Feed ingredients for carnivorous fish species: alternatives to fishmeal and other fishery resources. FAO Fish. Cir., No. 881. FAO, Rome, 35 pp.

-9Table 1. Formulations {g kg- 1 diet, dry weight basis) of the diets used to evaluate the effectiveness of krill as a protein source for juvenile chinook salmon. Ingredient

Diet 1

Herring meal, whole Blood flour {spray-dried) Whey, dried Air-dried euphausiid meal Wheat starch {J:~regelatinized) Vitamin premix 1 Mineral premix 2 Sardine oil Canola oil Soybean lecithin Ascorbic acid Choline chloride {60%) Finnstim'l¥ 3 Alpha-cellulose

635.0 40.0 60.0 50.0 58.0 20.0 20.0 50.0 40.0 10.0 2.0 5.0 10.0 0.0

Diet 2 524.6 40.0 60.0 150.0 60.1 20.0 20.0 52.5 42.0 10.5 2.0 5.0 10.0 3.3

Diet 3 414.3 40.0 60.0 250.0 62.2 20.0 20.0 55.0 44.0 11.0 2.0 5.0 10.0 6.6

1 The vitamin premix supplied the following levels per kg of dry diet: Vitamin A {acetate), 5000 IU, Vitamin D3, 2400 IU; Vitamin E {dl-alpha tocopheryl acetate), 300 IU; pantothenate {dl-calcium pantothenate), 165 mg; pyridoxine {pyridoxine HCI), 40 mg; riboflavin, 60 mg, folic acid, 15 mg; thiamine {thiamine mononitrate), 50 mg; d-biotin 1.5 mg; Vitamin B12 , 0.09 mg; menadione {menadione sodium bisulfite), 18 mg; myo-inositol 400 mg; and niacin, 300 mg. 2 The mineral premix supplied the following levels of element per kg of dry diet: Co {CoCI 2 6H 20), 2 mg; Cu {CuS0 4 5H 2 0), 6 mg; Fe {FeS0 4 7H 2 0), 100 mg; Mg {MgS0 4 7H 20), 350 mg; Mn {MnS0 4 H 20), 75 mg; K {K 2S0 4 ), 2000 mg, Se {Na 2Se0 3 ), 0.10 mg; Na {NaCI), 1967 mg, Zn {ZnS0 4 7H 20), 80 mg; I {KI0 3 ), 5 mg; and F {NaF), 4.5 mg. 3 Finnstim'l¥ -a commercial feeding stimulant and palatability enhancer, consisting of a mixture of mostly betaine and free amino acids.

- 10Table 2. Formulation of the commercial Oregon moist pellet {OMP) diet. Ingredient

Dry mix Fish meal Cottonseed meal Wheat germ meal Whey, dried Corn distiller's dried solubles Vitamin premix 1 Mineral premix 2 Wet mix Wet fish, pasteurized Marine oil Choline chloride {70%)

Amount {g kg- 1 as-fed mix)

316.0 150.0 57.0 50.0 40.0 15.0 1.0 300.0 66.0 5.0

1 The vitamin premix supplied the following levels per kg of diet: Vitamin

E, 502

IU; menadione sodium bisulfite complex, 5.9 mg; dl-calcium pantothenate, 105.7

mg; pyridoxine HCI, 17.7 mg; riboflavin, 52.9 mg; niacin, 188 mg; folic acid, 12.7 mg; thiamine mononitrate, 23.6; d-biotin, 0.59 mg; Vitamin B 12 , 0.059 mg; myoinositol, 132 mg; and ascorbic acid, 892 mg. 2 The mineral premix supplied the following levels per kg of diet: Cu {CuS0 ), 1.53 4 mg; Fe {FeS0 4 7H 2 0), 10 mg; Mn {MnS0 4 ), 75.3 mg; Zn {ZnS0 4 ), 74.9 mg; and I

{KI0 3 ), 0.5 mg.

- 11 Table 3. Proximate compositions (g kg- 1dry matter) of the experimental diets used to evaluate the effectiveness of krill meal as a protein source for juvenile chinook salmon. Diet 1 1 2 3 4

Moisture 88 ± 6 96 ± 5 102 ± 3 297 ± 0.2

Protein 543 ±4 543 ±6 554 ±5 583 ± 0.5

Lipid 196 ± 4 190 ±4 192 ±3 200 ± 0.5

136 134 132 89

Ash ±3 ±4 ±2 ± 0.4

1 The test diets contained: 50 g (Diet 1), 150 g {Diet 2), or 250 g (Diet 3) of airdried krill meal kg- 1 on a dry weight basis. OMP (Diet 4) served as a commercial

reference control. Values represent the mean ± SEM (n =4) of the four different batches of experimental diets produced.

Table 4. Growth and survival of juvenile chinook salmon fed diets containing different levels of krill meal or commercial OMP for 56 days. Diet 1

Initial weight

1 2 3 4 Pooled sd 2

(g) 2.78 2.89 2.82 2.73 0.48

Final weight (g) 12.30b 12.58b 13.12a 11.74c 2.09

Specific growth rate

Survival

(% day- 1 )

(%)

2.65 2.63 2.74 2.60 0.05

96.3 94.6 95.7 95.4 1.5

1 The test diets contained: 50 g (Diet 1 ), 150 g (Diet 2), or 250 g (Diet 3) of airdried krill meal kg- 1 on a dry weight basis. OMP (Diet 4) served as a commercial reference control. 2 Pooled standard deviation (square root of the error mean square). Means within a column that do not have or share a common postscript letter are not significantly different (P > 0.05). For initial and final weights, n = 120, and for specific growth rate and survival, n = 2.

- 12 Table 5. Feed consumption, feed to gain ratios, and protein efficiency ratios (PER ) for juvenile chinook salmon fed the experimental diets containing different levels of krill meal or commercial OMP for 56 days.

Diet 1 1 2 3 4 Pooled sd 2

Feed consumgtion (% body weight- 1 day- 1) 2.34 2.45 2.33 2.44 0.08

Feed to gain ratio

PER

0.87 0.90 0.83 0.93 0.03

2.12ab 2.06ab 2.19a 1.84b 0.08

1 The test diets contained: 50 g (Diet 1 ), 150 g (Diet 2), or 250 g (Diet 3) of airdried krill meal kg- 1 on a dry weight basis. OMP (Diet 4) served as a commercial

reference control. 2 Pooled standard deviation (square root of the error mean square). Means (n = 2) within a column that do not have or share a common postscript letter are not significantly different (P > 0.05). Table 6. Initial and final whole-body proximate compositions (g kg- 1 as-is) of juvenile chinook salmon fed diets containing different levels of krill meal or commercial OMP for 56 days. Diet 1 1 2 3 4 Pooled sd 2 Initial fish

Moisture 760 770 762 750 7 770

Protein 156 156 159 143 5 143

lipid 57 60 51 68 9 53

ash 10.0 10.2 9.9 8.6 0.9 19.8

1 The test diets contained: 50 g (Diet 1 ), 150 g (Diet 2), or 250 g (Diet 3) of airdried krill meal kg- 1 on a dry weight basis. OMP (Diet 4) served as a commercial reference control. 2 Pooled standard deviation (square root of the error mean square). Means (n = 2) within a column that do not have or share a common postscript letter are not significantly different (P > 0.05).

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