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Articles 1621 - 1650 of 1812

Full-Text Articles in Animal Sciences

Physiological Response To Hooking Stress In Largemouth Bass (Micropterus Salmoides), A. Wayne Gustaveson May 1978

Physiological Response To Hooking Stress In Largemouth Bass (Micropterus Salmoides), A. Wayne Gustaveson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent concern about large initial and delayed mortalities resulting from tournament angling for largemouth bass has indicated that it would be desirable to further evaluate the fate of fish that are released after being captured by angling. This study was designed to evaluate sublethal physiological disruptions caused by hooking stress after largemouth bass were played under standardized conditions (0-5 minutes) and to estimate the time needed for recovery of the homeostatic mechanisms (to 72 hours). Blood lactate was used as a measure of metabolic fatigue; plasma osmolality and chloride measurements were used to evaluate osmoregulatory disturbances and gill ion-exchange; and …


Population Dynamics And Net Production Of Brown Trout (Salmo Trutta) In Two Areas Of A High Gradient Mountain Stream, Jeffrey C. Gosse May 1978

Population Dynamics And Net Production Of Brown Trout (Salmo Trutta) In Two Areas Of A High Gradient Mountain Stream, Jeffrey C. Gosse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Estimates of the brown trout (Salmo trutta) population were made in two areas of the Blacksmith Fork River, Cache County, Utah, from June 1972 to June 1973. Additional data were obtained on movement, growth, mortality, biomass, production, and yield.

Population density was highly variable in the area where habitat alterations had occurred, but was relatively uniform where the habitat was undisturbed. The brown trout exhibited little movement except during spawning season. Instantaneous growth and mortality rates are provided for each age group.

Mean annual biomass in the two areas was 12.0 and 10.2 grams per square meter and …


Mathematical Equations Describing Chick Performance And Carcass Composition As A Function Of Diet Protein And Energy Levels, Naiyana Nakhata Jan 1978

Mathematical Equations Describing Chick Performance And Carcass Composition As A Function Of Diet Protein And Energy Levels, Naiyana Nakhata

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Previous work at Utah State University determined minimum levels of different nutrients that would produce the maximum rate of gain or gain/feed ratio by feeding graded levels of the nutrients. Fitting broken lines to the data from work with one nutrient tended to underestimate the minimum requirement for that nutrient. It appeared that the response was not linear up to the level required to give maximum performance as the "broken line" approach to estimating the requirement assumes. It seemed worthwhile to try to describe the relation between ration level of a nutrient and chick performance by means of a mathematical …


Some Intermountain Endemics, Arthur H. Holmgren May 1977

Some Intermountain Endemics, Arthur H. Holmgren

Faculty Honor Lectures

A growing concern for the welfare of endangered or threatened plant and animal species has developed during the past few years, coinciding with an awareness of mankind's deleterious influence on the environment. Technological man has altered vast areas of the earth's surface to such an extent that many species have been endangered or made extinct. Transcontinental highways, shopping malls, industrial parks, home sites where they shouldn't be, and huge acreages turned over by the plow for monocultures, have taken a toll on our native vegetation to such an extent that many species have either lost their diversity or have disappeared. …


Possible Impacts Of The Expected Shift From Cow-Calf To Cow-Calf-Yearling Enterprises On Beef Production And Beef Prices, Suliman H. Abdalla May 1977

Possible Impacts Of The Expected Shift From Cow-Calf To Cow-Calf-Yearling Enterprises On Beef Production And Beef Prices, Suliman H. Abdalla

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Retention of young cattle and marketing older cattle from the range has been suggested as one of the profitable means of adjustment for the cow-calf operator. This study was to determine the impacts of the shift from cow-calf ranching operation to cow-calf-yearling operation on the feed energy budget of the ranch, cow herd size, beef production and market price of beef. Ten alternative livestock management options involving cow-calf-yearling operations were tested for these impacts, using two representative Utah size ranches (150 and 300 cow ranches).

The extra feed needed to accomodate the increased number of yearlings and the decrease required …


Economics Of Carry-Over Forage Production, Increased Grazing Season Length, And Increased Livestock Production From Rangeland Fertilization, Dean L. Roberts Jr. May 1977

Economics Of Carry-Over Forage Production, Increased Grazing Season Length, And Increased Livestock Production From Rangeland Fertilization, Dean L. Roberts Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper entails the economic and biological responses of both rangeland grasses and livestock grazing rangeland grasses to nitrogen fertilization. Five sites received graduated rates of fertilizer in previous studies. Analysis showed all sites failed to exhibit a significant carry-over response to fertilization. Determination of optimum rate or optimum reapplication schedule was not possible due to residual nitrogen present in the soil. Spring application of fertilizer produced the greatest returns from one site while the other site studied failed to produce a profitable response from either spring or fall application.

Calf weight gains were shown to be curvilinear and resulted …


An Economic Analysis Of Predation Control And Predatory Sheep Losses In Southwestern Utah, R. Garth Taylor May 1977

An Economic Analysis Of Predation Control And Predatory Sheep Losses In Southwestern Utah, R. Garth Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To provide accurate data concerning sheep losses resulting from predation, a verification study of sheep predation was initiated in March 1972 in the Cedar City area of Utah. In cooperation with the Cedar City Wool Growers Association and Southern Utah State College Experimental Farm, ten sheep ranches were chosen as sample operations, forming the data base for the initial phase of the study (1972-1974).

Cooperating ranchers were asked to promptly report all sheep carcasses or injured sheep, so that an examination could immediately be made to ascertain the cause of death or injury. Daily horseback searches were also conducted on …


Rodent Density And Species Composition In The Snake River Birds Of Prey Natural Area, Idaho, Jon R. Montan Jr. May 1977

Rodent Density And Species Composition In The Snake River Birds Of Prey Natural Area, Idaho, Jon R. Montan Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rodent densities were estimated in the major vegetation types of the Snake River Birds of Prey Natural Area in 1975 and 1976 by a combination of live-trapping and kill-trapping. Only deer mice (Peromyscus maniculatus) were numerous enough to permit reliable density estimates. Relative densities of other rodent species were indicated by kill-trap capture rates. Densities of deer mice correlated well (r = 0.99) with kill-trap capture rates. The use of kill-trapping in place of live-trapping in 1976 permitted extensive sampling throughout the 1930 km2 study area. Differences were found among the major vegetation and land-use types in …


Biological Manipulation Of Blackbrush (Coleogyne Ramosissima Torr.) By Browsing With Goats, Frederick D. Provenza May 1977

Biological Manipulation Of Blackbrush (Coleogyne Ramosissima Torr.) By Browsing With Goats, Frederick D. Provenza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to provide data on responses of Angora goats and blackbrush (Coleogyne ramosissima) to a biological manipulation program. Blackbrush utilization levels averaged 30, 16, and 6 percent (545, 367, and 147 kg per hectare) for the heavily, moderately, and lightly browsed pastures, respectively; removal rates of 77, 38, and 19 percent (1164, 582, and 291 kg per hectare) were projected.

Statistically significant differences in body weight loss (P=0.052) were noted for goats browsing in different replications. Goats lost an average of 14 and 19 percent of body weight in replications one and two, …


Feed Composition, Animal Nutrient Requirements, And Computerization Of Diets, Paul V. Fonnesbeck, Lorin E. Harris, Leonard C. Kearl Jan 1977

Feed Composition, Animal Nutrient Requirements, And Computerization Of Diets, Paul V. Fonnesbeck, Lorin E. Harris, Leonard C. Kearl

Animal, Dairy, and Veterinary Science Faculty Publications

The Symposium is directed to use feed composition and nutrient requirement information to calculate animal diets. Mathematical models (equations) that describe the utilization of nutrients by animals and the variables affecting animal nutrient requirements is presented. The aim is to use feed information and equations that describe nutrient utilization and animal requirements to formulate the most profitable diet for animals in various physiological states and environments. Methods for solving livestock feeding and management problems are presented.


Breeding Biology And Pesticide-Pcb Contamination Of Western Grebe At Bear River Migratory Bird Refuge, Mark L. Lindvall May 1976

Breeding Biology And Pesticide-Pcb Contamination Of Western Grebe At Bear River Migratory Bird Refuge, Mark L. Lindvall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The breeding biology of western grebe was studied at Bear River Migratory Bird Refuge, Utah in 1973 and 1974. More than 300 nests were located and data gathered on nesting habitat and success. Western grebe at Bear River selected nest sites for nearness to open water of approximately 30 em in depth. At least one young was hatching in 21 percent of the nests. Avian predation and abandonment of nests following drops in water levels caused the greatest loss of nests. Chlorinated hydrocarbons monitored in western grebes showed DDE, DDD, PCB, 1260, and PCB 1254 levels in 24 breast muscle …


A Computer Approach To Performing Mppa Testing, James W. Shaw May 1976

A Computer Approach To Performing Mppa Testing, James W. Shaw

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

In the highly competitive cattle market of today a scientific method, by which a rancher can base a judgement, moderated by experience as to which animals are to be kept, as proven by superior performance, can be a valuable asset.

This record performance testing system was designed to demonstrate the value of adequately kept records. Its purpose is to help ranchers develop records of herd performance, inventory, and improve management practices by more informed decisions. The system, through its representative, provides a means by which ranchers can obtain information on new ideas in animal production, health, sanitation, nutrition, management practices, …


The Horse Population Of Utah And Its Impact, Scott Stewart Mckendrick May 1976

The Horse Population Of Utah And Its Impact, Scott Stewart Mckendrick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

PART I

The horse numbers of Utah had not been accurately counted since the early 1960's. It was estimated that horse and pony numbers were reaching heights as recorded before the age of tractors and automobiles. Horsemen in Utah were asking for financial assistance for public horse facilities from the Utah legislature. The first part of this study was to survey the horse population to determine an accurate count of Utah horses.

PART II

In order to be satisfied that the horse industry deserved the spending of public funds, it was necessary to know the economic contribution of the horse …


Effects Of Group, Individual, And Isolated Rearing Of Dairy Calves On Weight Gain And Social Development, Val D. Warnick May 1976

Effects Of Group, Individual, And Isolated Rearing Of Dairy Calves On Weight Gain And Social Development, Val D. Warnick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thirty-six dairy calves were observed for four months to determine the effect of three housing methods, group, individual and isolated on body weight gain, feed consumption, age when started to consume grain, daily activity patterns, open field test of behavior and social rank. Six calves were assigned to each of the three treatments in two separate trials of eighteen calves. These calves were raised in their treatment for approximately two months and then weaned and placed together in a group of eighteen for two more months.

Treatments ranked in order from high to low according to least squares means for …


Multiple Hemoglobins In Rainbow Trout, Salmo Gairdneri, And Cutthroat Trout, Salmo Clarkii, Jeffrey Carl Braman May 1976

Multiple Hemoglobins In Rainbow Trout, Salmo Gairdneri, And Cutthroat Trout, Salmo Clarkii, Jeffrey Carl Braman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nine hemoglobins from adult rainbow trout have been isolated by starch gel electrophoresis using a Trisborate buffer system, pH 8.7. Six fast and two slow anodally migrating hemoglobins, and one slow cathodally migrating hemoglobin were observed in all specimens.

The nine hemoglobins have been purified by DEAE cellulose ion exchange chromatography followed by starch gel electrophoresis.

The subunit structure of each purified hemoglobin has been partially examined by gel electrofocusing (GEF) in .5 percent polyacrylamide gels containing 8M urea and lmM dithiothereitol (DTT). Tetrameric combinations of one, two, three, and four polypeptide chains are present.

Twelve hemoglobins have been isolated …


Food Interactions Between Utah Prairie Dogs And Cattle, Dennis Crocker-Bedford May 1976

Food Interactions Between Utah Prairie Dogs And Cattle, Dennis Crocker-Bedford

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the food interactions between Utah prairie dogs (Cynomys parvidens, Allen) and cattle (Bos taurus). During 1974 and 1975, three prairie dog colonies near Panguitch, Utah, were studied intensely: "Oldfield" was chosen to represent colonies near fields of alfalfa (Medicago sativa); "Lowercrested" was chosen to represent colonies below 2,200 meters above sea level (a.s.l.) which were not near alfalfa, and "Uppercrested" was chosen to represent colonies above 2,200 meters a.s.l. which have been planted with crested wheatgrass.

Visual observations were made of Utah prairie dogs to determine their diets. Livetrapping of prairie …


Feeding Behavior Of Pen Reared Mule Deer Under Winter Range Conditions, Michael A. Smith May 1976

Feeding Behavior Of Pen Reared Mule Deer Under Winter Range Conditions, Michael A. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the feeding responses of mule deer to a system of spring livestock grazing. The specific purposes were 1) to determine botanical composition of diets selected by mule deer on a winter range subjected to previous spring grazing by sheep compared to one with no sheep grazing and 2) to develop a basis for predicting selection of individual plants by deer, based on physical characteristics of the plants and the species and physical proximity of associated plants.

The study was conducted within the framework of a completely randomized experimental design with two treatments. Variables controlled for each unit …


Forage Selection And Nutrition Of Sheep And Goats Grazing In The Tunisian Pre-Sahara, Rudolfo Ricardo Griego May 1976

Forage Selection And Nutrition Of Sheep And Goats Grazing In The Tunisian Pre-Sahara, Rudolfo Ricardo Griego

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nomadic pastoralism has been the traditional method of utilizing grazing resources in arid and semi-arid regions of Africa. However, increased sedentarization accompanied by growing human and animal populations during the past two decades is thought to be accelerating the desertification process, or desert expansion. The specific interactions of the grazing animal with this process has been speculated upon but not studied in detail. A comparative study was initiated during the spring grazing season of 1974 to determine sheep and goat nutritional and production responses, as well as patterns of vegetative selection and utilization under the pastoral system currently employed in …


Laboratory Apparatus For Providing Diel Temperature Regimes For Aquatic Animals, Wayne A. Wurtsbaugh, G. Davis Jan 1976

Laboratory Apparatus For Providing Diel Temperature Regimes For Aquatic Animals, Wayne A. Wurtsbaugh, G. Davis

Watershed Sciences Faculty Publications

In studies of the effects of elevated temperature on aquatic organisms, little emphasis has been placed on modeling the fluctuating temperatures to which organisms are exposed in nature. To some extent this may be related to problems of design and maintenance of apparatus for fluctuating temperature control. The complexity of apparatus used to provide cycled temperatures has ranged from manually controlled valves for introducing water of different temperatures into aquariums (Kelso 1972), to a complex and expensive feedback system, regulated by rotating cams, that controls the temperature of influent water (Honeywell Cam Programmer Thermometers, Fort Washington, Pennsylvania). To facilitate studies …


Effect Of Salinity On Glycogen Content In The Brine Shrimp, Artemia Salinas, Of Great Salt Lake, Christon H. Merkley Aug 1975

Effect Of Salinity On Glycogen Content In The Brine Shrimp, Artemia Salinas, Of Great Salt Lake, Christon H. Merkley

Undergraduate Honors Capstone Projects

The brine shrimp, Artemia salinas, is one of the few organisms to be found in the hostile environment of the Great Salt Lake. Salt concentrations in the lake are found to exceed those in the oceans. In such an environment, the utilization of energy, even after it has been procured, presents a problem. The life inhabiting the lake has developed extraordinary adaptations to this and similar problems.

Electron micrographs produced by Dr. Nabil Youssef of Utah State University have revealed that unusual quantities of glycogen can be found in the muscle of brine shrimp taken from the Great Salt Lake. …


The Reproductive Cycle Of Male Uinta Ground Squirrels And Its Relationship To Pineal N-Acetyltransferase And Monoamine Oxidase In The Testes, Hypothalamus And Pituitary, Robert Alexander Palmer May 1975

The Reproductive Cycle Of Male Uinta Ground Squirrels And Its Relationship To Pineal N-Acetyltransferase And Monoamine Oxidase In The Testes, Hypothalamus And Pituitary, Robert Alexander Palmer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study was made of the reproductive cycle of male Uinta ground squirrels (Spermophilus armatus) during the activity seasons of 1973 and 1974 and during the aestivation/hibernation (A/H) period of 1973-1974. Physiological data collected were compared to changes in monoamine oxidase (MAO) activity of the testes, pituitary and hypothalamus and to pineal N-acetyltransferase activity.

Male Uinta ground squirrels began emerging from their burrows on April 12, 1973, and April 8, 1974, with average body weights of 302 g and 301 g, respectively. Body weight did not increase greatly during breeding, but rose rapidly to over a 500 g …


Relationships Between Teat Shape, Teat Erosion, California Mastitis Test, And Milk Production In A Large Dairy Herd, John Sephen Malan May 1975

Relationships Between Teat Shape, Teat Erosion, California Mastitis Test, And Milk Production In A Large Dairy Herd, John Sephen Malan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Data were collected from a 1,000 cow commercial dairy unit during three different time periods to determine the interrelationships between teat shape, teat erosion, mastitis (as measured by the California Mastitis Test and somatic cell counts), and milk production.

Results showed no relationship between teat shape or teat end erosion and milk or fat production. The relationship between teat end erosion and mastitis appeared to be masked by the high level of teat erosion. There was an indication that cows with flat and cone shaped teat ends were prone to higher California Mastitis Test scores than cows with pointed, round, …


A Comparison Of Three Methods Used To Analyze Pronghorn Antelope Diets, Leonard J. Shandruk May 1975

A Comparison Of Three Methods Used To Analyze Pronghorn Antelope Diets, Leonard J. Shandruk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An increasing interest in fecal analysis as a method of determining diets of herbivores prompted research to determine if this method could be used successfully to determine diets of pronghorn antelope found in Utah's cold desert rangelands. In addition to fecal analysis, quantitative estimates of pronghorn diets were derived from rumen analysis and feeding site observations. Rumen samples were analyzed by three different methods: (1) microscopic, (2) gravimetric, and (3) point frame. In addition to field experiments, samples from a feeding trial with a diet of known composition were used to determine whether or not differential digestion of plant epidermis …


An Analysis Of Sound Communication In The Water Vole, Microtus Richardsoni (Rodentia: Microtinae), Dane R. Tang May 1975

An Analysis Of Sound Communication In The Water Vole, Microtus Richardsoni (Rodentia: Microtinae), Dane R. Tang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Adult members of the species Microtus richardsoni were used to study the importance of acoustic communication in these voles. Tests were run with single individuals and nonbreeding pairs of voles to obtain recordings and sonagraphs of sounds emitted during exploration of a new cage, agonistic encounters, encounters with a potential predator and in response to miscellaneous aversive stimuli. Of the four groups of tests conducted, sounds were used by M. richardsoni during the last three. The results of this study showed that the water vole emitted ten different call types or sounds. These sounds were separated by similarity into Group …


Food And Distribution Of Underyearling Brook And Rainbow Trout In Castle Lake, California, Wayne A. Wurtsbaugh, R. Brocksen, C. Goldman Jan 1975

Food And Distribution Of Underyearling Brook And Rainbow Trout In Castle Lake, California, Wayne A. Wurtsbaugh, R. Brocksen, C. Goldman

Watershed Sciences Faculty Publications

A difference was found in the summer distribution of underyearling brook trout, Salvelinus fontinalis (Mitchill), and planted rainbow trout, Salmo gairdneri Richardson, in Castle Lake, California. Brook trout underyearlings oriented to the bottom and were found primarily in shallow water on the eastern shore of the lake near springs. The rainbow trout underyearlings were more pelagic and were found in the littoral areas along the entire shoreline. Gravimetrically, the food eaten during the summer by brook trout underyearlings was 13% terrestrial, 11% limnetic, and 76% benthic. Rainbow trout ate 15% terrestrial, 15% limnetic, and 70% benthic food. In summer, rainbow …


An Evaluation Of In-Stream Structures Designed To Provide Fish Habitat, Charles H. Call Jr. May 1974

An Evaluation Of In-Stream Structures Designed To Provide Fish Habitat, Charles H. Call Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In-stream concrete structures were studied through model tests and river tests. The model studies indicated that four designs provided good habitat in the model stream. These structures were the inverted weir, the "V" structure, the slab with legs and the cylinder. Through the river studies it was determined that these structures did not influence enough of the total river area to be effective in providing good fish habitat. Also an appreciable amount of yearly maintenance would be required to free the structures from silting in, debris, and vandalism. The slab with legs was the only promising structure.


Vocalizations In A Population Of Green-Tailed Towhees (Chlorura Chlorura), Timothy Andrus Burr May 1974

Vocalizations In A Population Of Green-Tailed Towhees (Chlorura Chlorura), Timothy Andrus Burr

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Studies of vocalizations in a montane population of Green-Tailed Towhees were conducted during the summer months of 1971 and 1972 in Cache County, Utah. The song and call repertoiries of 10 breeding pairs were recorded and analyzed on a sound spectograph.

Males averaged 8.7 different song and 18.2 different not types. Song variation on the population level is high (58 different songs) but the sharing of these songs among the males is low (22.4). Populational note structure is equally diverse but reveals a greater degree of sharing (75%).

Both males and females used three calls, the meow, tick, …


Manufacture Of Monterey Cheese From Preacidified Milk, Faisal O. Mohamed May 1974

Manufacture Of Monterey Cheese From Preacidified Milk, Faisal O. Mohamed

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whole milk acidified to pH 5.3 with hydrochloric acid was used for the manufacture of Monterey cheese. The milk was inoculated with one and one-half percent lactic starter and set with 12.5 ml rennet per 1000 pounds of milk. Normal washing treatments resulted in cheese with moisture in excess of 44 percent. Moisture content was brought below 44 percent by using wash water at a temperature such that the water-curd-whey mixture was 35 C. The pH of cheese made by preacidification was all between 5.21 and 5.09. No acid defects were encountered. Preacidification eliminated chance of spoilage or losses caused …


Nutrition Of Sheep Grazing Foothill Big Game Range In Spring, Kurt J. Kotter May 1974

Nutrition Of Sheep Grazing Foothill Big Game Range In Spring, Kurt J. Kotter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sheep with esophageal fistulas were used to determine the daily intake, nutritive content and digestibility of forage at three periods and two stocking intensities during the spring of 1972 on a typical foothill range in northern Utah.

Heavy grazing under a season-long regime did not influence the concentrations of dietary chemical components when compared to moderate grazing; however, it did depress the digestibility of cellulose and organic matter. There was a significant decline in the dietary chemical components due to forage maturation. Digestibility of organic matter and cellulose were significantly higher in the early spring as compared to late spring. …


Effects Of Exercise On Serum Lactate Dehydrogenase Activity Of Catchable-Size Hatchery Rainbow Trout, Salmo Gairdneri, Gerlad T. Klar May 1973

Effects Of Exercise On Serum Lactate Dehydrogenase Activity Of Catchable-Size Hatchery Rainbow Trout, Salmo Gairdneri, Gerlad T. Klar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Effects of exercise and the relative condition of exercised fish were viii evaluated for two strains of rainbow trout. Circular tanks fitted with a paddle were used to continuously exercise the fish and a stamina tunnel was used to evaluate the condition of exercised trout. Trout were exercised continuously at one fish-length per second and one-half fish length per second. Serum LDH activity in Shephard-of-the-Hills (Missouri) rainbow trout acclimated to 10 C increased two fold during the first four days of exercise. Serum LDH activity returned to control levels by the tenth day of exercise. Serum LDH activity in Shephard-of-the-Hills …