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Full-Text Articles in Animal Sciences

Effect Of Rain Leaching On Chemical Composition Of Alfalfa Hay, Mercedes M. Garcia De Hernandez May 1981

Effect Of Rain Leaching On Chemical Composition Of Alfalfa Hay, Mercedes M. Garcia De Hernandez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Yield and chemical changes of second-cutting alfalfa hay treated with artificial rain were determined in a 2 x 3 x 2 factorial experiment. Factors were 2 stages of maturity (1 = late vegetative; 2 = early bloom), 3 levels of artificial rain applied (1 = no rain; 2 =low or approximately 5 mm; 3 = high or approximately 20 mm), and 2 times of applying artificial rain (1 = when drying forage was 40-60% dry matter; 2 = when drying forage was 60-75% dry matter). Thirty samples of alfalfa were collected at the 2 stages of maturity when the alfalfa …


Models For Estimating Energy And Protein Utilization For Feeds, Muhammad Fadel Wardeh May 1981

Models For Estimating Energy And Protein Utilization For Feeds, Muhammad Fadel Wardeh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Data on the proximate nutrient content of feedstuffs, digestibility and energy utilization available from the International Feedstuffs Institute (Utah State University) were used to develop mathematical models for estimating energy and protein utilization of five classes of feedstuffs for various kinds of animals.

Classes of feedstuffs were subdivided into more related subclasses. Furthermore, data from all feeds were pooled together then subgrouped into more related subgroups in an attempt to gain high precision in prediction of digestible proximate nutrients and TDN from a single chemical entity by the use of simple regression models (Y = bo + b1x …


Effect Of Toxaphene On Collagen Synthesis In Fish Tissue: Organ Culture Studies And Prolyl Hydroxylase Activity Assay, Charles Franklin Luke May 1981

Effect Of Toxaphene On Collagen Synthesis In Fish Tissue: Organ Culture Studies And Prolyl Hydroxylase Activity Assay, Charles Franklin Luke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Toxaphene is reported to cause defects in the collagen of fish. Chronic exposure to toxhaphene weakens the backbone of fish by decreasing the amount of collagen and usually increasing the amount of calcium in the bone which results in a more brittle and fragile bone.

We investigated the possible direct action of toxaphene on collagen synthesis by exposing vertebral and swim bladder organ cultures obtained from unexposed rainbow trout (Salmo gairdneri) fingerlings to the same lot of toxaphene found to cause this defect in vivio. Collagen produced by these organ cultures was measured by: (1) total 3 …


An Economic Analysis Of Prairie Dog Control, Alan Robert Collins May 1981

An Economic Analysis Of Prairie Dog Control, Alan Robert Collins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Prairie dog control was found to be economically feasible on the Conata basin in South Dakota with future annual maintenance control to prevent re-invasions. The large difference between the present net worth values of the two viewpoints ($2587 for the U.S. Forest Service acting as an agent of the sovereign and $109,011 for the ranchers) was due to the added costs of environmental considerations included in the U.S. Forest Service control program, but assumed not to be included in control by ranchers. In order for prairie dog control to remain economically feasible, annual maintenance control for the U.S. Forest Service …


Seasonal Temperature Preference Of Adult Mountain Whitefish, Prosopium Williamsoni, Jean M. Ihnat May 1981

Seasonal Temperature Preference Of Adult Mountain Whitefish, Prosopium Williamsoni, Jean M. Ihnat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Temperatures selected seasonally by adult mountain whitefish were measured in the laboratory in a horizontal gradient. Final preferendum estimates, based on acute (3-hour) preference tests conducted with fish acclimated to 5, 10, and 15 C each season, were 17.7 C (pre-spawning), 11.9 C (post-spawning), 9.9 C (winter), and 16.3 C (spring). Seasonal influence on temperature selection was evident on the basis of differences in final preferenda, covariance analysis of responses of laboratory-acclimated fish, and temperature selection by fish held at ambient river temperatures. Post-spawning and winter groups selected lower temperatures than did pre-spawning and spring groups. Pre-spawning fish selected temperatures …


Some Morphological And Chemical Responses Of Blackbrush (Coleogyne Ramosissima) To Goat Browsing: Influences On Dietary Blackbrush Selection By Goats And Cattle, Frederick D. Provenza May 1981

Some Morphological And Chemical Responses Of Blackbrush (Coleogyne Ramosissima) To Goat Browsing: Influences On Dietary Blackbrush Selection By Goats And Cattle, Frederick D. Provenza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Domestic goats were used to modify the growth form of blackbrush, a spinescent shrub occurring in nearly monospecific stands on several million hectares of rangeland in the southwestern United States. The objective of this research was to evaluate goat browsing as a means of improving these rangelands for cattle. Winter goat browsing stimulated spring twig growth from basal and axillary buds which resulted in increased production.

Twig production by heavily browsed plants (>95 percent removal of current season's twigs) was a function of precipitation, soil depth, branch location on the plant, and period of rest after browsing. As precipitation …


Lactation And Weaning Weight Relationships In Hereford And Simmental-Hereford Cows In Southern Utah, William E. Zimmerman May 1980

Lactation And Weaning Weight Relationships In Hereford And Simmental-Hereford Cows In Southern Utah, William E. Zimmerman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lactation and weaning weight relationships were studied in 37 cows grazing Southern Utah irrigated pastures during the summer of 1979. The herd included 23 Hereford cows ranging in age from 2 to 12 years and 14 Simmental-Hereford half-blood cows aged 3 to 9 years. The suckling calves were sired by Hereford bulls.

The average daily milk yield of 6.16 kg was affected by the cow breed. Simmental-Hereford cows produced 7.11 kg of milk per day, while the Herefords produced 5.21 kg per day. Milk production declined with increased days in lactation. The decline was linear in the Simmental- Hereford cows …


The Development Of Methodology For Gas Liquid Chromatographic Determination Of Plant Sugars In Maturing Reed Canarygrass, Allan Scott Bittner May 1980

The Development Of Methodology For Gas Liquid Chromatographic Determination Of Plant Sugars In Maturing Reed Canarygrass, Allan Scott Bittner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was concerned with development of chromatographic methods suitable for determination of plant sugars. The resultant methodology was applied to the comprehensive study of plant carbohydrates as they vary during plant growth. Plant cell walls were isolated with boiling water followed by delignification with acid chlorite. The soluble portions were hydrolyzed with 2N sulfuric acid and the total sugars and individual monosaccharides were quantified using gas chromatography and colorimetry. The insoluble residues were hydrolyzed with 72% sulfuric acid followed by dilution with water to 2N and further hydrolysis. The effects of duration of delignification and acid hydrolysis were interpreted …


Leptophos Metabolism In The Rat: An In Vivo Study Of Oxidative Versus Conjugative Modes Of Metabolism, David Richard Hampson May 1980

Leptophos Metabolism In The Rat: An In Vivo Study Of Oxidative Versus Conjugative Modes Of Metabolism, David Richard Hampson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objectives of this research were to examine the metabolism in vivo of the pesticide leptophos in the rat under normal conditions and during inhibition of the mixed-function oxidases and during depletion of glutathione. Glutathione is a cofactor in the conjugation reactions of the glutathione-S-transferases. Both the mixed-function oxidase system and the glutathione-S-transferases have been shown to be important in the biotransformation of other organophosphate pesticides.

Urinary metabolites of leptophos were extracted, derivatized and subsequently analyzed by gas-liquid chromatography. The methods used to analyze for alkyl phosphonates were subject to several shortcomings and modifications of the original procedure were necessary. …


Evaluation Of Six Strains Of Rainbow Trout (Salmo Gairdneri) Stocked As Fingerlings In Porcupine Reservoir, Utah, Mark Hudy May 1980

Evaluation Of Six Strains Of Rainbow Trout (Salmo Gairdneri) Stocked As Fingerlings In Porcupine Reservoir, Utah, Mark Hudy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Different strains of rainbow trout (Salmo gairdneri), Ten Sleep, Sand Creek, Beitey, Shepherd-of-the-Hills, New Zealand, Fish Lake-Desmet, Desmet, were compared for survival to the creel, growth and catchability after being stocked in a fluctuating 80 ha Utah reservoir. Fish were stocked in the spring and fall as fingerlings and monitored by creel censusing, gill netting and electrofishing. Fish were tagged with coded wire snout tags prior to stocking. An angler opinion survey was conducted to determine angler satisfaction with numbers and size of fish caught.

Regardless of strain, spring stocking was superior to fall stocking in survival to …


Reproductive Success Of The White-Faced Ibis: The Effects Of Pesticides And Colony Characteristics, Benjamin B. Steele May 1980

Reproductive Success Of The White-Faced Ibis: The Effects Of Pesticides And Colony Characteristics, Benjamin B. Steele

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Reproductive success of white-faced ibis (Plegadis chihi) was measured in nine colonies on marshes in northern Utah during 1979. The effects of pesticides and characteristics of colonies and sub-colonies on reproductive success were examined.

DDE was present in all 80 eggs sampled and had a geometric mean concentration of 1.25 ppm. Shell thickness of 176 eggs was 4.3 percent below pre-1945 thickness. Shell thickness was weakly correlated with residues of DDT, DDE, Dieldrin, and heptachlor epoxide. Residues of these four pesticides were all correlated with each other. However, because of the stronger correlations between shell thickness and two …


Resource Partitioning In Breeding Populations Of Marsh Hawks And Short-Eared Owls, Susan C. Linner May 1980

Resource Partitioning In Breeding Populations Of Marsh Hawks And Short-Eared Owls, Susan C. Linner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During the 1979 breeding season four pairs of northern harriers, or marsh hawks (Circus cyaneus) and four pairs of short-eared owls (Asio flammeus) were studied in Cache Valley, Utah. The study was concerned solely with diurnal resource utilization, and did not examine the owls' nocturnal activities. The home range of each harrier pair overlapped substantially with that of an owl pair. Percent habitat overlap for hawk-owl pairs varied from 39 percent to 72 percent. Observations were made to determine if differences existed in their utilization of habitat and food resources, or in their daily and seasonal …


Production Of Mountain Whitefish (Prosopium Williamsoni) In Altered And Unaltered Reaches Of Two Intermountain Streams In Their Alluvial Flood Plains, Michael J. Ottenbacher May 1980

Production Of Mountain Whitefish (Prosopium Williamsoni) In Altered And Unaltered Reaches Of Two Intermountain Streams In Their Alluvial Flood Plains, Michael J. Ottenbacher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Estimates of production and related parameters (growth rate, density, standing crop) were made for populations of mountain whitefish in altered and "unaltered" areas of the Blacksmith Fork and Logan River, Utah from spring 1975 through summer 1976. Capture records of marked whitefish were also analyzed to describe fish movement and check on assumptions implicit in the population estimator.

Mean weights and instantaneous growth rates of whitefish were similar at all sites for comparable size/age groups. Among sites, differences in production per sampling interval and annual production were due mainly to differences in standing crop and/or age structure.

Estimates of mountain …


Effects Of Forage Availability On Voluntary Intake And Feeding Behavior Of Grazing Heifers, Anastasios S. Nastis May 1979

Effects Of Forage Availability On Voluntary Intake And Feeding Behavior Of Grazing Heifers, Anastasios S. Nastis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Forage intake by animals is an important factor in determining production of livestock products from rangelands. However, relatively little is known of effects of such forage variables as availability and distribution in space upon intake. Even less is known about how the grazing animal modifies its feeding tactics when confronted with diminishing or limited supplies of available forage and how such altered behavior may affect the animal's energetic cost for existence. Forage intake, body weight gain, grazing time and biting rate of Angus heifers was related to forage availability and plant height on semiarid crested wheatgrass rangeland during the late …


Spectral Signature Studies For Application In Deer Census Using Remote Sensing Techniques, Maran C. Pate May 1979

Spectral Signature Studies For Application In Deer Census Using Remote Sensing Techniques, Maran C. Pate

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was performed to determine the spectral signatures of deer and their natural background elements for censusing purposes. Consideration was given to atmospheric transmittance, acceptable flying weather, and terrain. Possible spectral bands between 0.3 and 14.0 μm were obtained (over a pathlength of 1500 feet at an altitude of 5000 feet) based upon atmospheric transmittance using the LOWTRAN 3B computer program. They are: 0.30 - 1.33, 1.49 - 1.79, 2.00 - 2.50, 3.00 - 3.16, 3.38 - 4.10, 4.59 - 5.05, and 8.00 - 13.33 μm, for transmittance greater than 75%. Weather conditions are favorable for flying and taking …


Interrelationships Between Benthic Macroinvertebrates And Habitat In A Mountain Stream, John M. Payne May 1979

Interrelationships Between Benthic Macroinvertebrates And Habitat In A Mountain Stream, John M. Payne

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study to determine habitat differences of benthic macroinvertebrates was conducted on the upper Strawberry River, Utah. The investigation was part of a large scale project to determine minimum stream flow requirements for trout. The effects of time, habitat, depth and velocity on the distribution of benthic fauna were evaluated.

Samples of benthic invertebrates (146 total) were collected every 2 months at 8 stations on the river from November, 1975 through August, 1976. Representatives of 59 taxa were collected. Eight taxa comprised 90 percent of the mean annual community standing crop in numbers. Biomass was not dominated by any group …


Linear Models For Estimating The Nutritive Value Of Sheep Diets, Michael L. Christiansen May 1979

Linear Models For Estimating The Nutritive Value Of Sheep Diets, Michael L. Christiansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Digestibility data were determined in 2 replications of a 2 x 3 x 2 x 2 factorial arranged experiment to: (1) determine the effects of forage type (grass vs alfalfa), forage maturity (late vegetative vs midbloom vs fullbloom), diet ingredients (forage only vs 50:50 forage plus corn), and diet texture (coarsely chopped vs pelleted) on the digestibility of diet chemical constituents by sheep; (2) develop equations to estimate digestible energy of sheep diets from nutrient content of the diet; and (3) compare popular chemical methods used to partition feed dry matter into fibrous and soluble components. Diets were fed to …


Causative Factors And Some Consequences Of Dystocia In Two-Year-Old Heifers, Delyn Jensen May 1979

Causative Factors And Some Consequences Of Dystocia In Two-Year-Old Heifers, Delyn Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Causative factors and some consequences of dystocia were examined in 3923 parturitions among Hereford and Angus x Hereford crossbred two-year-old heifers. Fifty percent of the parturitions required some assistance. Minor assistance was required in 34.5% of the parturitions and major assistance involving use of a calf puller, in 15.1%. Caesarean section and foetotomy were rendered in 0.3% and .05% of the cases, respectively. Abnormal presentation at birth, which included leg back, head back, backwards, hiplock and breech, was observed in only 2.9% of the births and therefore is a minor contributor to dystocia. The major causes of dystocia were not …


Coyote-Prey Relationships In Curlew Valley During A Period Of Low Jackrabbit Density, Stephen W. Hoffman May 1979

Coyote-Prey Relationships In Curlew Valley During A Period Of Low Jackrabbit Density, Stephen W. Hoffman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coyote-prey relationships were examined in Curlew Valley, northern Utah and southern Idaho, during a period of low jackrabbit density (from September 1973 to May 1975). The Utah and Idaho portions of Curlew Valley were treated separately. Field work provided estimates of relative and absolute rodent densities as well as relative coyote density each spring and fall. Laboratory analysis of over 2,300 scats and 249 stomachs provided detailed information on coyote diets. Jackrabbit population data for northern Utah were obtained from L. Charles Stoddart.

Four species, Peromyscus maniculatus, Perognathus parvus, Eutamias minimus, and Dipodomys ordii comprised over 90 …


Biology, Reproductive Potential And The Impact Of Fishing Pressure On The Bluegill Fishery Of Pelican Lake, Uintah County, Utah, Bob D. Burdick May 1979

Biology, Reproductive Potential And The Impact Of Fishing Pressure On The Bluegill Fishery Of Pelican Lake, Uintah County, Utah, Bob D. Burdick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Certain aspects of the biology of two species of fish, bluegill (Lepomis macrochirus) and largemouth bass (Micropterus salmoides), and the assessment of fishing pressure upon the sport fishery of Pelican Lake, Uintah County, Utah, a 680 ha warmwater lake, were studied between April 1, 1976 and June 30, 1978. The growth rate of bluegills (sexes combined) was fairly rapid; the mean back-calculated total lengths from ages one through nine were 55, 112, 166, 194, 211, 229, 245, 256 and 259 mm. The growth of largemouth bass was 104, 194, 271, 316, 350, 405 and 416 mm …


Development And Validation Test Of A Mule Deer Habitat Rule, Glenn Gephart May 1979

Development And Validation Test Of A Mule Deer Habitat Rule, Glenn Gephart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A mathematical description of Rocky Mountain mule deer (Odocoileus hemionus hemionus) habitat was developed and subjected to validation testing using correlation and multiple regression statistical techniques. Data were collected on a central Utah study area, which was divided into mountain and desert regions.

Data on deer utilization and several habitat components from 86 study plots visited in 1976 were used to develop a habitat rule. Data from 46 study plots visited in 1977 were used to test the accuracy of the rule. Deer utilization was determined from pellet group counts on 20 0.001 ha pellet plots at each …


Some Effects Of A Grazer, Hyalella Azteca On Ecosystem Level Properties In Aquatic Microcosms, Martin D. Werner May 1979

Some Effects Of A Grazer, Hyalella Azteca On Ecosystem Level Properties In Aquatic Microcosms, Martin D. Werner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study to determine some ecosystem level effects of an aquatic invertebrate grazer, Hyalella azteca, was performed in aquatic ix microcosms. Impact of the grazer was assessed in three general areas: 1) inorganic nutrient levels of the microcosm water column, 2) productivity and respiration of the biotic community, and 3) plant community composition in the microcosms.

The grazing amphipod caused inorganic phosphorus and nitrogen (except ammonia) levels to be elevated in the microcosms. The increase was due, at least partially, to excretion of nutrients into the water by the amphipod. The presence of H. azteca did not significantly …


A Discriminant Function Model Of Gray-Headed Junco Habitat, Andrew R. Grainger May 1978

A Discriminant Function Model Of Gray-Headed Junco Habitat, Andrew R. Grainger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper presents a description of gray-headed junco habitat in the form of a model based on discriminant function analysis. Junco nests were found by searching randomly located grids on a 7.8 km2 study area in central Utah. Vegetation data was gathered on 500 m2 circular plots surrounding nests and contrasted with similar data from searched grids where nests were not found. The model explains 28 percent of the between-groups variance and correctly classifies 68 percent of the plots.

Plant cover types are good predictors of areas where gray-headed juncos nest, while plant community type descriptions do not …


Production And Intake Responses Of Dairy Cows Fed Four Levels Of Malic Acid, Juan Carlos Martinez Alferez May 1978

Production And Intake Responses Of Dairy Cows Fed Four Levels Of Malic Acid, Juan Carlos Martinez Alferez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thirty-two lactating cows were assigned at random to four treatments of malic acid to determine if these levels had an effect on milk production, milk composition, feed intake, and efficiency of feed utilization. Malic acid allotment for each treatment consisted of 1) 15.4, 2) 11.6, 3) 7.7, and 4) 0 grams of malic acid fed per kilogram of concentrate. Concentrate was fed according to production at a rate of one kilogram per two kilograms of milk in excess of 9.1 kilograms of milk per cow daily. Alfalfa hay was fed free choice and corn silage at a rate of 11.4 …


A Description And Analysis Of Behavior Patterns Among Uinta Ground Squirrels, Thomas Earl Morse May 1978

A Description And Analysis Of Behavior Patterns Among Uinta Ground Squirrels, Thomas Earl Morse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research describes and analyzes the behavior of free-living Uinta ground squirrels (Spermophilus armatus) temporally, spatially and with reference to differences in sex, age, population density and habitat. In addition, the relationships between local meteorological parameters and time spent above ground are described and analyzed.

The frequency of eight behaviors, feeding, moving, encounters, upright, motionless, grooming, nest gathering and calling, among ground squirrels was found to be labile, varying in frequency with time of day, period of the season, sex, age, population density and habitat, and varying in spatial distribution within the home range.

The dominant behavior, feeding, …


The Social Behavior Of Brown Bears At Mcneil River, Alaska, Allan L. Egbert May 1978

The Social Behavior Of Brown Bears At Mcneil River, Alaska, Allan L. Egbert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The social behavior of brown bears (Ursus arctos) was studied during the summers of 1972 and 1973 as bears fished for salmon at McNeil River, Alaska. Study objectives were to determine behavioral characteristics of bears in relation to sex and age, changes in social behavior over a 40-day long fishing season, social and environmental parameters correlated with the occurrence of behavior, and to test the hypothesis that brown bears modify social behavior in a feeding aggregation to exploit a resource limited in time and space.

Over one-half of the agonistic interactions consisted of passive deferrals. Encounters that included …


Bait Shyness And Neophobia In Several Species Of Osteichthyes: An Extension Of Taste Aversion Studies To The Superclass Pices, Brent W. Roberts May 1978

Bait Shyness And Neophobia In Several Species Of Osteichthyes: An Extension Of Taste Aversion Studies To The Superclass Pices, Brent W. Roberts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three experiments were conducted with five species of tropical fish to investigate the phenomena of taste aversion and food neophobia. In addition, an experiment determined specifically if position in the tank could acquire conditioned aversive properties.

In Experiment 1 , four habituated fish were fed novel meat-flavored pellets on the treatment day. Six were made ill within 30, 60, or 90 minutes (2 subjects each) by intragastric administration of syrup or Epicac. The following day all were fed familiar commercial pellets. On the second day after treatment, all were offered the meat-flavored pellets. Results showed longer latencies, more tasting, and …


Adaptive Significance Of Lactate Dehydrogenase B2 Isozymes In Rainbow Trout, Salmo Gairdneri And A Biochemical Genetic Comparison Of Cutthroat Trout (Salmo Clarki) Populations, Gerald Thomas Klar May 1978

Adaptive Significance Of Lactate Dehydrogenase B2 Isozymes In Rainbow Trout, Salmo Gairdneri And A Biochemical Genetic Comparison Of Cutthroat Trout (Salmo Clarki) Populations, Gerald Thomas Klar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rainbow trout lactate dehydrogenase (LDH) B2' B2' , B2' B2" and B2" B2" phenotypes were tested under a variety of conditions for swimming endurance, oxygen consumption rates, and blood pH, pO2, and lactate. The B2" B2" phenotype exhibited a lower swimming endurance, under a limited oxygen supply, than the B2' B2' and B2' B2" phenotypes. Blood pH at fatigue did not differ among the LOH phenotypes that swam under low oxygen conditions (2 mg/1). …


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 …