USGS Science⌕ Search
Home/Archive/USGS

USGS · 70160588

The nutrition of salmonid fishes. II. Studies on production diets

E. M. Wood·W. T. Yasutake·A.N. Woodall·J.E. Halver
View original source ↗Export metadata ↓

Abstract

In 69 production diets fed to hatchery salmonids, there was a wide variation in the ingredients of the diets and in their content of protein, fat, carbohydrate and ash. There was a close correlation between the body composition of hatchery-raised fish and the composition of the diets fed. The data indicated, however, that differences in hatchery management, such as level of feeding, were also important contributing factors in producing the observed body composition of hatchery fish. Wild fish had a markedly different body composition characterized by a much lower level of fat and relatively higher protein and mineral content The effect on survival of differences in body composition between wild and hatchery fish is discussed. There is a clearly defined need for additional research on the nutritional requirements of salmonids, the relationship between body composition and ability to survive, and for quality control in hatchery nutrition.

Explore related subjects

Journal of NutritionArticle

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

E. M. Wood, W. T. Yasutake, A.N. Woodall, J.E. Halver. 1957. The nutrition of salmonid fishes. II. Studies on production diets. https://doi.org/10.1093/jn%2F61.4.479

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS1984

Effect of excess dietary riboflavin on growth of rainbow trout

Fingerling rainbow trout were fed semipurified diets containing graded levels of supplemental riboflavin (3, 35, 42, 49, 56, 63, 70, 100 and 600 mg/kg of diet) to determine if dietary riboflavin in excess of requirements decreases growth. In three trials with three sizes of fish (mean initial weights, 0.5, 3.2 and 4.3 g) and two water temperatures (8.3° and 15°C), no significant diet-related growth inhibition was detected. The results suggest that rainbow trout, like other animals, are insensitive to excesses of dietary riboflavin and that the growth depression reported by other workers was the result of some other dietary influence or of faulty experimental design.

Journal of Nutrition↗
USGS1983

Factors affecting dietary requirement and deficiency signs of L-tryptophan in rainbow trout

Two experiments were conducted to determine the concentration of dietary tryptophan needed for optimal growth and survival of fingerling rainbow trout ( Salmo gairdneri ), to characterize signs of tryptophan deficiency, and to ascertain the effects of niacin on deficiency signs. Test diets containing either hydrolyzed or intact casein were fed with graded levels of added L-tryptophan (0.0, 0.25, 0.50, 0.75 and 1.0 g/100 g protein). Maximum growth occurred at 0.75 and 0.50 g tryptophan in fish fed hydrolyzed and intact casein, respectively. Changes in mineral and amino acid mixtures in the intact casein diet yielded a cation-anion (Na + K - Cl) balance of + 15.3 meq/100 g diet and pH of 6.44, compared with a balance of -21.3 and -25 meq, and pH 5.8 and 4.4 for unmodified hydrolyzed and intact casein diets, respectively. Analysis of growth by the polynomial regression function; Y = 0.16 + 0.429 X - 0.26 X 2 , where Y = mean daily gain in grams, and X = grams of added tryptophan/100 g protein, predicted that at least 0.58 g of tryptophan was needed for maximum weight gain. Analysis of apparent pathology-free fish by the function; Y = 34.33 + 147.33 X = 83.87 X 2 , where Y = percentage with no signs of deficiency, and X = grams of added tryptophan, predicted that 0.63 g tryptophan/100 g protein was needed for optimum health scores. Deletion of supplemental niacin did not affect fish response to tryptophan.

Journal of Nutrition↗
USGS1979

Influence of dietary zinc on cataracts in rainbow trout (Salmo gairdneri)

The purpose of this study was to determine the cause of lens cataracts in hatchery trout fed diets containing white fish meal. After preliminary investigations, three experiments were conducted with fry of rainbow trout ( Salmo gairdneri ) that were fed practical-type diets containing either 40% herring meal (control diet) or 40% white fish meal with and without various mineral supplements. In all experiments, the trout fed herring meal grew well and had normal lenses. Those fed the diet containing white fish meal without supplement grew slowly and developed bilateral cataracts determined by using a slit-lamp biomicroscope. The severity of cataracts was increased by supplementing the diet with a mixture of minerals (phosphates and carbonates of calcium, sodium and potassium). Cataracts were prevented, however, with supplemental Na2EDTA or zinc but not by supplements of manganese, copper, iron or various other minerals. The metabolic alterations responsible for the zinc-deficiency cataract were not determined.

Journal of Nutrition↗