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G. L. Rumsey

Publications and source records attributed to G. L. Rumsey.

At least 19 recordsLinked to original sources
USGS1994

History of early diet development in fish culture, 1000 B.C. to A.D. 1955

This paper traces the observations and speculations of early fish culturists as they sought to define the feeds necessary to keep hatchery fish alive. Although prescientific ideas about feeding fish existed in Egypt and China over three millennia ago, it was not until the 1700s that scientific studies of feeding and digestion by fish were documented. Aside from several books that provided early anecdotal accounts of feeds and feeding, much of the technical literature up to the 1930s is found in a few journals and relatively obscure bulletins. Such was the state of knowledge regarding the feeding of fish until about 1927 when Clive McCay, a professor at Yale University, and Abram Tunison, a hatchery worker, began some part‐time research on the nutritional requirements of trout at Connecticut's Burlington Fish Hatchery. In June 1932, these men founded an experimental hatchery, designed to study the nutrition, feeds, and feeding of fish, at Cortland, New York; this hatchery was operated under the auspices of the federal Bureau of Fisheries, the Conservation Department of New York State, and Cornell University. Over the next 25 years, it was research from this hatchery as well as from other federal, state, and university facilities that led to the development of purified test diets and the identification of the (unknown) growth factors in fresh meat, both essential criteria for scientific diet formulation, The first nutritionally complete diets appeared about 1955.

Progressive Fish-Culturist↗
USGS1993

Chemical and nutritional evaluation of soya protein preparations as primary nitrogen sources for rainbow trout (Oncorhynchus mykiss)

Five soya-bean preparations that had been subjected to various physicochemical processing procedures were chemically defined in respect to proximate analysis, amino acid analyses, protease inhibitor activity, soluble oligosaccharides and antigenicity. These soya preparations were then formulated, along with a low-temperature fish meal control, into six isonitrogenous and isocaloric experimental diets. The diets were fed to rainbow trout ( Oncorhynchus mykiss ) in feeding trials as well as in tests using specially constructed metabolic chambers. Based on the chemical and biological results, we concluded that soya-bean oligosaccharides do not have to be removed or modified for maximum growth or nitrogen utilization by rainbow trout. Likewise, the protease or trypsin inhibitor activity, which was low for all experimental treatments, did not appear to be a major factor in determining fish performance. Although the results regarding naturally occurring soya antigens only suggested allergenicity, it is concluded that more attention should be focused on these heat-stable proteins with antigenic or allergenic potential in fish diets.

Animal Feed Science and Technology↗
USGS1993

Fish meal and alternate sources of protein in fish feeds: Update 1993

Close to 12% of the world's 6.5 million metric tons of fish meal is used for aquaculture feeds. If current trends continue, roughly 20% to 25% of total world fish meal production could be used for aquaculture by the year 2000. Fish stocks used in fish meal reduction, however, appear to be in worldwide decline. A growing fish farming industry and a stagnating, if not diminishing, supply of fish meal have sobering economic and technologic implications for fish culture. Unless suitable alternate protein sources are found or other animal feeds begin to rely less on fish meal, fish production costs can be expected to increase dramatically. A precedent was set by the poultry industry, the most economically successful and competitive of the animal agriculture industries. Twenty years ago, the poultry industry consumed up to 80% of fish meal supplies. Through deliberate and well-organized research into alternate protein sources, the industry now uses less than 40% of supplies, and the trend is toward complete independence from fish meal. A comparable research effort is needed for aquaculture. Considering the biotechnologies available, plant proteins, processed to remove enzyme inhibitors and other antinutritional factors and properly supplemented with essential amino acids and minerals where needed, could produce results at least equivalent to those obtained with fish meal.

Fisheries↗
USGS1992

Nutritional value of dietary nucleic acids and purine bases to rainbow trout (Oncorhynchus mykiss)

Rainbow trout were fed diets with graded levels (0.6%, 1.6%, 2.5%, and 4.1%) of a yeast nucleic acid extract corresponding to dietary Saccharomyces cerevisiae levels of 7.5%, 20%, 30% and 50% or diets supplemented isonitrogenously (0.8% N) with free purines (adenine, guanine, xanthine, and hypoxanthine) in two 12-week studies. Fish fed increasing levels of yeast extract manifested significant ( P < 0.05) corresponding incremental increases in growth and nitrogen retention. No negative effects on feed intake were observed. When fish were fed supplemental free purines, adenine was shown to be a potent inhibitor of feed intake and growth. While supplementation with the remaining purines did not negatively affect feed intake or growth, carcass nitrogen retention was significantly depressed, indicating the lack of a nitrogen-sparing effect. Our results indicate that the nutritional significance of free dietary adenine versus nucleic acid-bound adenine in yeast or yeast nucleic acid is an important consideration in evaluating the suitability of single cell proteins in fish feed formulations.

Aquaculture↗
USGS1991

Digestibility and energy values of intact, disrupted and extracts from brewer's dried yeast fed to rainbow trout (Oncorhynchus mykiss)

Although fish meal has historically been used as the primary source of protein in fish feeds, brewer's dried yeast (BDY) is presently being investigated as a primary replacement for fish meal. As little is known about the ability of fish to utilize BDY, studies were conducted to study bioavailability of intact BDY as well as several fractions derived from the disrupted yeast to rainbow trout. Dried BDY was fed to rainbow trout and digestibility and energy values were determined. When the yeast cells were fully disrupted, the absorption of nitrogen increased by more than 20% and the metabolizable energy of the yeast by more than 10%. Energy and nitrogen digestibility were further increased after the removal of all wall material and separation of nitrogen into amino acid and nucleic acid fractions. Disruption of the cell wall significantly increased the nutritional value of BDY for salmonid fishes. The findings suggest that further research be conducted on the use and economy of BDY as a primary nitrogen source in fish feeds.

Animal Feed Science and Technology↗
USGS1990

Effects of dietary a-linolenic acid on n-3 fatty acids of rainbow trout lipids

The effects of α-linolenic acid enriched diets on the lipid composition of rainbow trout ( Oncorhynchus mykiss ) muscle and liver were determined. Diets containing 0, 4, 10 or 20% (wt/wt) linseed oil were fed to 280 trout for up to 64 days. Linolenic acid levels in total lipid, neutral lipid and phospholipid of liver and muscle increased with duration of intake. The linolenic acid content of total lipid in muscle increased from 10 mg to 355 mg/100 g flesh. There was no significant increase in the elongated desaturated products, i.e., eicosapentaenoic or docosahexaenoic acids, in either tissue during the feeding period.

Lipids↗
USGS1988

Effect of feeding level and dietary electrolytes on the arginine requirement of rainbow trout (Salmo gairdneri)

Experiments were conducted to determine the effect of level of feeding (restricted feeding and feeding to satiation) and dietary variations in the balance of monovalent minerals on the arginine requirement of rainbow trout fingerlings. Based on growth and efficiency of feed utilization for growth, the arginine requirement was lower (3.5% of protein) when fish were fed to satiation than when they were fed at a restricted level (4.2% of protein). When calculated on the basis of the amount of arginine consumed per day, however, the requirements were similar for fish subjected to the two methods of feeding. Three balances (acidic, neutral, and alkaline) of sodium, potassium and chloride were used in several experiments. The arginine requirement tended to be higher when fish were fed diets containing the alkaline as compared to the acidic balance of minerals. These studies indicate that the method of feeding has a significant effect on the dietary concentration of arginine needed to maximize growth rate and feed utilization in rainbow trout.

Aquaculture↗
USGS1987

Interactions among dietary minerals, arginine and lysine in rainbow trout (Salmo gairdneri)

Studies were conducted to determine whether interactions occur among dietary lysine, arginine and monovalent minerals in rainbow trout. In one experiment, rainbow trout fingerlings were fed diets containing three levels of lysine (2.4, 3.1 and 3.8 g per 100 g diet), two levels of arginine (1.7 and 2.5 g per 100 g diet) and two mixtures of Na + K + and Cl in a 3×2×2 factorial design. The mixtures varied in the proportions of cations to anions such that Cl equalled the sum of Na + and K + (cations − anions = 0 mEq/kg diet) in one mixture and exceeded the sum of Na + and K + (cations − anions = −200 mEq/kg diet) in the second mixture. Growth and efficiency of feed conversion were not affected by dietary lysine and arginine in fish fed diets containing − 200 mEq/kg balance, but when fish were fed diets containing a 0 mEq/kg balance, 3.8% lysine and a combination of 3.1% lysine and 2.5% arginine depressed both measures of response. Trout receiving the 0 mEq/kg cation-anion balance had significantly higher free histidine concentrations and lower free lysine concentrations in muscle and higher hepatic arginase activity (P≤0.01) than those receiving −200 mEq/kg. In another experiment, trout were fed diets containing three levels of K + (21, 191 and 360 mEq/kg), two levels of Na + (21 and 191 mEq/kg) and two levels of Cl − (179 and 347 mEq/kg) in a 3×2×2 factorial design. Growth and efficiency of feed conversion were depressed and hepatosomatic index increased with higher levels of dietary K + (P≤0.01), Na + (P≤0.05) and Cl (P≤0.01), with significant K + x Cl + (P≤0.01) and K + x Na + x Cl (P≤0.05) interactions. Increasing dietary K + resulted in increased levels of muscle free histidine and decreased levels of muscle free lysine and arginine (P≤0.01), while increasing dietary Cl increased muscle free lysine, the effect of which was dependent on dietary potassium (K + x Cl − , P≤0.01). It is concluded that dietary levels of K + , Na + and Cl − , irrespective of overall cation-anion balance of these minerals, affects growth rate, efficiency of feed utilization and the metabolism of basic amino acids in tissues of trout. Excess lysine causes depressed growth and efficiency of feed utilization. These effects were due to a lysine toxicity rather than a lysine-arginine antagonism, as they were not prevented by supplemental dietary arginine.

Fish Physiology and Biochemistry↗
USGS1984

Effects of dietary excesses of branched-chain amino acids on the metabolism and tissue composition of lake trout ( Salvelinus namaycush )

1. Excesses of either leucine, isoleucine or valine were fed in separate experiments to determine if the branched-chain amino acid antagonism reported in other animals occur in trout ( Salvelinus namaycush ). 2. Parameters measured include growth rate, feed utilization efficiency, plasma and muscle-free amino acids, carcass composition and branched-chain amino acid aminotransferase. 3. Dietary excesses of leucine or isoleucine caused an increase in the valine requirement. 4. The inability of leucine and isoleucine supplementations to ameliorate the effects of excess dietary valine are interpreted as a valine toxicity rather than an antagonism.

Comparative Biochemistry and Physiology, Part A: P↗