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Growth and Acute Temperature Tolerance of June Sucker Juveniles Fed Varying Dietary Protein and Lipid Levels With and Without Supplemental Dicalcium Phosphate
Author(s) -
Sealey Wendy M.,
Gaylord T. Gibson,
Toner Matt,
Ilgen Jason,
Fraser W. C.,
Hooley Christopher G.,
Barrows Frederic T.
Publication year - 2013
Publication title -
north american journal of aquaculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 41
eISSN - 1548-8454
pISSN - 1522-2055
DOI - 10.1080/15222055.2012.736449
Subject(s) - biology , phosphate , zoology , factorial experiment , nutrient , feed conversion ratio , juvenile , sucker , fish <actinopterygii> , food science , body weight , fishery , biochemistry , ecology , endocrinology , anatomy , statistics , mathematics
Reports from hatcheries have demonstrated that commercially available diets are inadequate for June Suckers Chasmistes liorus and suggest that fish quality can be improved through species‐specific diet optimization. To determine dietary protein and lipid levels for juvenile June Suckers, practical‐type diets were formulated with 35, 40, or 45% protein and 8, 12, or 16% lipid and tested in a 3 × 3 factorial design. Two additional diets (45% protein and 16% lipid [45:16] without dicalcium phosphate supplementation and 45:16 with 2× dicalcium phosphate) were formulated to test the necessity of dicalcium phosphate supplementation. Each diet was fed to three replicate tanks (average initial fish weight ± SD = 4.48 ± 0.24 g) of fish per treatment (85 fish/tank); only duplicate tanks were used for the nondicalcium phosphate‐supplemented treatment. Fish were reared in 80‐L tanks supplied with 4 L/min of 22°C spring water and fed 6–4% body weight (BW)/d by automated belt feeders, 6 d/week. At the end of 12 weeks of culture, tissue samples were obtained to determine nutrient partitioning. An acute temperature challenge was also conducted to investigate dietary adequacy. Significant effects of diet on growth and temperature tolerance were observed. Fish fed the diet with 45% crude protein gained more weight than did fish fed 40% or 35% crude protein, and fish fed 16% dietary lipid gained more weight than did fish fed 12% and 8% crude lipid. However, the composition of this growth indicated that fish fed the 16% lipid stored larger amounts of lipid in both the visceral cavity and the muscle. A significant negative interactive effect of dietary protein and lipid on temperature tolerance was observed at 45% crude protein and 16% lipid. Results of this study define acceptable ranges of dietary protein and lipid for juvenile June Suckers and provide culturists information to make better choices regarding appropriate diets for this species.