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R. R. Smith

Publications and source records attributed to R. R. Smith.

31 records · Page 2Linked to original sources
USGS1991

Water resources data, Washington, water year 1990

The Water Resources Division of the U.S. Geological Survey, in cooperation with State, local, and other Federal agencies, obtains a large amount of data pertaining to the water resources of Washington each water year. These data, accumulated during many water years, constitute a valuable data base for developing an improved understanding of the water resources of the State. To make these data readily available to interested parties outside the Geological Survey, the data are published annually in this report series entitled "Water Resources Data - Washington."

Washington↗
USGS1988

Growth, carcass composition, and taste of rainbow trout of different strains fed diets containing primarily plant or animal protein

Ten rainbow trout ( Salmo gairdneri ) strains were evaluated during early growth from 30 g to 250 g on two diets — one based on plant protein (soybean and cottonseed meal) and the other on animal protein (fish meal). Diets were formulated to be nutritionally isocaloric and isonitrogenous. Fish were fed identical starter diets until they weighed 30 g. Significant differences in growth rate were found attributable to fish strain. Differences associated with diet were nonsignificant. Percent dress-out data based on eviscerated weight, deboned weight, and fillet weight also showed significant differences in yield attributable to fish strain, but not to diet. Carcass composition varied among strains, but none of the differences could be attributed to diet. Organoleptic tests showed no differences in flesh acceptability associated with either fish strain or diet, and all trout tested were equally acceptable to human taste panels.

Aquaculture↗
USGS1987

Methods of controlling growth of steelhead

Steelhead (Salmo gairdneri) held at 15°C and fully fed from demand feeders grow larger than desired by the time of their normal release into streams. The effect of limited feed intake on growth, body composition, and potential for migration to the sea was investigated. Dilution of feed by 10‐40% with sodium bentonite was not effective in reducing growth; the fish used the nutrients more efficiently and their growth was nearly equal to that of controls. Hand feeding of a decreased ration reduced growth rate, but about a 50% reduction in feed was required to effect the desired reduction in growth rate. Fish were able to compensate for fasting periods of short duration and significant growth reduction did not occur until the fasting periods were 4 d or longer. Alternate feeding and fasting periods of equal lengths produced the desired growth rate reduction. Estimated potential for emigration by these anadromous fish was not reduced by fasting periods as long as 28 d.

Progressive Fish-Culturist↗
USGS1984

Determining fat digestibility in trout using a metabolic chamber

Fat digestibilities were determined in rainbow trout utilizing a metabolism chamber. Separate and quantitative fecal extracts were freeze dried and total lipids were extracted. Lipid digestibilities were comparable to those obtained by other methods (85‐91%). This method avoids problems due to leaching and the variable of accelerated passage through the gut encountered in other methods.

Progressive Fish-Culturist↗
USGS1980

Effect of leaching on apparent digestion coefficients of feedstuffs for salmonids

Fecal excretions were collected from rainbow trout (Salmo gairdneri) in metabolism chambers. In this method of collection the daily excretion is suspended in about 1 L of water. Aliquots of the suspension were separated into solid and liquid fractions by settling, centrifuging, or filtering. Solid and liquid fractions and the unseparated suspension were analyzed for total nitrogen. Digestion coefficients for protein were calculated on the basis of solids and on total suspension. More than half of the fecal nitrogen was in the liquid fraction. Digestion coefficients for protein based only on solids were about 10 percentage points higher than those based on the total suspension, apparently because of leaching when the fecal matter was exposed to water. Digestibility and metabolizable energy of 55 diet ingredients, obtained by the metabolism chamber method, were tabulated.

Progressive Fish-Culturist↗
USGS1978

Net energy maintenance requirements of salmonids as measured by direct calorimetry: Effect of body size and environmental temperature

Most studies of metabolic rates and energy requirements in aquatic animals have been conducted using indirect methods wherein heat production estimates were based on O 2 consumed and CO 2 produced. The purpose of the present study was to determine the feasibility of direct calorimetry as a method for measuring heat production of fish and to determine the effect of environmental temperature and body size on the metabolic rate of several species. An adiabatic bomb calorimeter was modified to hold living fish and to measure small increments of heat. Heat production of rainbow, brook and lake trout, and Atlantic salmon weighting 1 to 4 g each was measured at temperatures ranging from 3° to 18°. Heat production of rainbow trout having individual body weights from 0.85 to 57.0 g was measured at 15°. Direct calorimetry was found to be a satisfactory method for measuring heat production of fish. Tests were reproducible and could be completed in 6 to 8 hours. The heat production changed linearly with temperature over the range tested. Regression equations for heat production for fish weighing 1 to 4 g were: for rainbow trout, HP = 0.59 + 0.0525T; for Atlantic salmon, HP = 0.66 + 0.0339T; for brook trout, HP = 0.37 + 0.0770T; and for lake trout, HP = 0.41 + 0.0680T where HP is kcal/kg/hr and T is temperature. The effect of size on metabolic rate was linear from 1 to 4 g and proportional to W 0.63 from 4 to 57 g.

Journal of Nutrition↗
USGS1978

Heat increment associated with dietary protein, fat, carbohydrate and complete diets in salmonids: comparative energetic efficiency

The heat increment (HI) of feeding, which is the increased heat production following consumption of food by an animal, accounts for as much as 30% of the ingested metabolizable energy (ME) in mammals and birds. The purpose of these experiments was to measure the HI associated with the feeding of a complete diet and purified fat, protein, and carbohydrate to salmonids. Measured amounts were fed and the heat production was measured by direct calorimetry. Increased heat production was observed about 30 minutes after feeding and remained elevated for 1 to 5 hours, depending on the amount and type of material fed. The HI of protein was much lower with fish than with mammals and amounted to <5% of the ingested ME. The HI's of carbohydrate and protein were not significantly different from each other but both were higher than fat. The HI, when complete diets were fed, was <3% of the ME. The net energy of protein is higher for fish than for birds or mammals. A major part of the superior energetic efficiency of fish is due to the low energy cost of protein metabolism.

Journal of Nutrition↗