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• 311. [Article] Hydraulic predictors and seasonal distribution of Manayunkia speciosa density in the Klamath River, CA, with implications for ceratomyxosis, a disease of salmon and trout

  The freshwater polychaete Manayunkia speciosa was identified as an obligate host of the salmonid parasite Ceratomyxa shasta in 1997, prompting increased research on the small benthic invertebrate. Ceratomyxa ...

  Citation × Citation Citation Abstract Copy Title: Hydraulic predictors and seasonal distribution of Manayunkia speciosa density in the Klamath River, CA, with implications for ceratomyxosis, a disease of salmon and trout Author: Jordan, Michelle S. The freshwater polychaete Manayunkia speciosa was identified as an obligate host of the salmonid parasite Ceratomyxa shasta in 1997, prompting increased research on the small benthic invertebrate. Ceratomyxa shasta infection in fish can cause mortality, and presents a disease risk for both hatchery and wild salmon and trout. Ceratomyxa shasta is endemic to rivers of the Pacific Northwest, and its effects have been particularly well documented in the Klamath River, Oregon and California. One option for managing C. shasta impacts is by decreasing densities of M. speciosa through habitat manipulation, thus decreasing amplification of the parasite. The Klamath River is regulated by irrigation and hydropower dams, thus manipulating the hydrograph to destabilize habitat is a possibility. Decreasing habitat through flow manipulation requires a thorough understanding of the hydraulic environment of polychaete habitat, and how that environment changes with discharge. This thesis proposes an influence diagram of physical variables driving M. speciosa density, and investigates several of them. Samples were collected for enumerating M. speciosa density from nine sites in the Klamath River over 15 months, and seasonal density changes were examined, as were the relationships between density and hydraulic variables (depth, average velocity, substrate size, Reynolds number, Froude number). Density increased directly with depth and inversely with velocity, and was greater on small (silt, sand) and large (boulder, bedrock) substrate relative to medium substrate (gravel, cobble). Density was highest in the summer (July, August, September), and there was evidence that summer densities were influenced by spring discharges through the mechanism of substrate mobilization. Differences in infection prevalence among seasons and habitats were also investigated; however, very low overall incidence of infection limited any conclusions. Based on these results, it is recommended that habitat modeling for management of M. speciosa populations include a habitat stability component that incorporates s whether peak discharge the previous year surpassed a stability threshold. Title: Hydraulic predictors and seasonal distribution of Manayunkia speciosa density in the Klamath River, CA, with implications for ceratomyxosis, a disease of salmon and trout Author: Jordan, Michelle S. The freshwater polychaete Manayunkia speciosa was identified as an obligate host of the salmonid parasite Ceratomyxa shasta in 1997, prompting increased research on the small benthic invertebrate. Ceratomyxa shasta infection in fish can cause mortality, and presents a disease risk for both hatchery and wild salmon and trout. Ceratomyxa shasta is endemic to rivers of the Pacific Northwest, and its effects have been particularly well documented in the Klamath River, Oregon and California. One option for managing C. shasta impacts is by decreasing densities of M. speciosa through habitat manipulation, thus decreasing amplification of the parasite. The Klamath River is regulated by irrigation and hydropower dams, thus manipulating the hydrograph to destabilize habitat is a possibility. Decreasing habitat through flow manipulation requires a thorough understanding of the hydraulic environment of polychaete habitat, and how that environment changes with discharge. This thesis proposes an influence diagram of physical variables driving M. speciosa density, and investigates several of them. Samples were collected for enumerating M. speciosa density from nine sites in the Klamath River over 15 months, and seasonal density changes were examined, as were the relationships between density and hydraulic variables (depth, average velocity, substrate size, Reynolds number, Froude number). Density increased directly with depth and inversely with velocity, and was greater on small (silt, sand) and large (boulder, bedrock) substrate relative to medium substrate (gravel, cobble). Density was highest in the summer (July, August, September), and there was evidence that summer densities were influenced by spring discharges through the mechanism of substrate mobilization. Differences in infection prevalence among seasons and habitats were also investigated; however, very low overall incidence of infection limited any conclusions. Based on these results, it is recommended that habitat modeling for management of M. speciosa populations include a habitat stability component that incorporates s whether peak discharge the previous year surpassed a stability threshold. Close

• 312. [Article] Tuberculosis in Pacific salmon and steelhead trout

  Tuberculosis in salmonoid fishes was first observed in the 1952 run of fall chinook salmon (Oncorhynchus tshawytscha) returning to the Bonneville Hatchery of the Oregon Fish Commission. In the studies ...

  Citation × Citation Citation Abstract Copy Title: Tuberculosis in Pacific salmon and steelhead trout Author: Ordal, Erling Josef, 1906-, Oregon. Fish Commission, Wood, James W. Tuberculosis in salmonoid fishes was first observed in the 1952 run of fall chinook salmon (Oncorhynchus tshawytscha) returning to the Bonneville Hatchery of the Oregon Fish Commission. In the studies reported here, tuberculosis was found not only in adult spring chinook but in silver salmon (0. kisutch), blueback salmon (0. nerka), and in anadromous and resident strains of rainbow trout (Salmo gairdnerii). Advanced tuberculosis was found in salmonoid fishes held in fresh water for two years or longer, as well as in adults returning from the sea. Lesions were most frequently observed in the liver, and varied in size from small miliary tubercles to huge necrotic areas, filled with characteristic acid-fast bacilli. The typical bacilli were found in stained smears from the kidney, heart, musculature, brain, intestines, pyloric caeca, and roe of infected fish. The disease was originally observed in sexually-underdeveloped fish, and there is indication that it interferes with sexual maturation. It was found that tuberculosis in marked salmon known to be of hatchery origin was extremely high - in some cases 100 percent. Tuberculosis was absent in the small number of silver and chum salmon examined which were known to be the progeny from natural spawning. It is suggested that dissemination of the disease may be due to fish-cultural practices such as the feeding of untreated carcasses and the viscera from tuberculous fish. Since acid-fast bacilli were found in the roe of some fish, it is also suggested that the disease may be transmitted to healthy eggs during the process of fertilization. Tuberculous adult spring chinook were found less capable of surviving to maturity after they reached the spawning grounds than were non-infected fish. It is likely that tuberculosis also influences the ability of salmon to survive during earlier stages of their life history. The incidence of tuberculosis in adult spring chinook entering the Dexter holding ponds on the Middle Fork of the Willamette River in 1955 and 1956 was 8.7 and 6.1 percent, respectively. The increase in incidence to 58.8 percent in 1957 is attributed to the increased dependency of the run on artificial propagation necessitated by the construction of Lookout Point Dam. Among chinook caught in the Columbia River gill-net fishery in. February and in May 1956, 12.3 and 10.5 percent, respectively, of those examined were tuberculous. Although these are spring chinook, it is believed that hatchery reared fall chinook also entered the catch, especially during May, and may have contributed to the number of tuberculous fish taken. Title: Tuberculosis in Pacific salmon and steelhead trout Author: Ordal, Erling Josef, 1906-, Oregon. Fish Commission, Wood, James W. Tuberculosis in salmonoid fishes was first observed in the 1952 run of fall chinook salmon (Oncorhynchus tshawytscha) returning to the Bonneville Hatchery of the Oregon Fish Commission. In the studies reported here, tuberculosis was found not only in adult spring chinook but in silver salmon (0. kisutch), blueback salmon (0. nerka), and in anadromous and resident strains of rainbow trout (Salmo gairdnerii). Advanced tuberculosis was found in salmonoid fishes held in fresh water for two years or longer, as well as in adults returning from the sea. Lesions were most frequently observed in the liver, and varied in size from small miliary tubercles to huge necrotic areas, filled with characteristic acid-fast bacilli. The typical bacilli were found in stained smears from the kidney, heart, musculature, brain, intestines, pyloric caeca, and roe of infected fish. The disease was originally observed in sexually-underdeveloped fish, and there is indication that it interferes with sexual maturation. It was found that tuberculosis in marked salmon known to be of hatchery origin was extremely high - in some cases 100 percent. Tuberculosis was absent in the small number of silver and chum salmon examined which were known to be the progeny from natural spawning. It is suggested that dissemination of the disease may be due to fish-cultural practices such as the feeding of untreated carcasses and the viscera from tuberculous fish. Since acid-fast bacilli were found in the roe of some fish, it is also suggested that the disease may be transmitted to healthy eggs during the process of fertilization. Tuberculous adult spring chinook were found less capable of surviving to maturity after they reached the spawning grounds than were non-infected fish. It is likely that tuberculosis also influences the ability of salmon to survive during earlier stages of their life history. The incidence of tuberculosis in adult spring chinook entering the Dexter holding ponds on the Middle Fork of the Willamette River in 1955 and 1956 was 8.7 and 6.1 percent, respectively. The increase in incidence to 58.8 percent in 1957 is attributed to the increased dependency of the run on artificial propagation necessitated by the construction of Lookout Point Dam. Among chinook caught in the Columbia River gill-net fishery in. February and in May 1956, 12.3 and 10.5 percent, respectively, of those examined were tuberculous. Although these are spring chinook, it is believed that hatchery reared fall chinook also entered the catch, especially during May, and may have contributed to the number of tuberculous fish taken. Close

• 313. [Article] Effect of callipyge gene on lamb growth, carcass characteristics, and meat quality

  Callipyge (CLPG, n=16) and normal (N, n=11) lambs were produced from Polypay dams and Dorset sires heterozygous for the CLPG gene to study the effects of the gene on growth and carcass and meat quality ...

  Citation × Citation Citation Abstract Copy Title: Effect of callipyge gene on lamb growth, carcass characteristics, and meat quality Author: Srinivasan, Haribaskar Callipyge (CLPG, n=16) and normal (N, n=11) lambs were produced from Polypay dams and Dorset sires heterozygous for the CLPG gene to study the effects of the gene on growth and carcass and meat quality parameters. CLPG lambs had higher average daily gain than N lambs (0.26 vs 0.23 kg/day, p<.05); however, the CLPG gene did not affect feed efficiency. Lambs were slaughtered in three groups to achieve moderate uniformity in slaughter weight. At the time of slaughter, weights of head, pelt, and internal organs were recorded. Two leg muscles, two shoulder muscles, the longissimus dorsi muscle, and two loin chops cut 2.5 cm thick, were dissected from each carcass. CLPG lambs had a higher dressing percent (p<.01) and lighter head, pelt, liver (all p<.01), and kidney/pelvic fat (p<.05). CLPG lambs had less fat over 12th rib (p<.05) and larger ribeye area (p<.01). CLPG lambs had greater weights of Biceps femoris (42%, p<.05), Semimembranosus (34%, p<.01), Triceps brachii (20%, p<.05), longissimus dorsi muscle (29%, p<.01) and whole leg (6%, p<.05) than N lambs. All the dissected muscles from all carcasses and one whole leg from each ewe lamb carcasses (n=11) were cooked to an internal temperature of 70°C. CLPG carcasses produced higher Warner-Bratzler shear values for loin chops (4.79 vs 2.93 kg, p<.01), Biceps femoris (3.94 vs 2.92 kg, p<.05), Semimembranosus (4.75 vs 3.46 kg, p<.05) and Longissimus dorsi muscle (5.29 vs 3.4 kg, p<.01) than N lambs. However, no significant differences were detected in shear values for Biceps femoris (3.10 vs 3.04 kg) or Semimembranosus (3.77 vs 3.29 kg) when the muscles were dissected after roasting the whole leg. The CLPG gene also had no effect on the shear values for two dissected shoulder muscles (Deltoid and Triceps brachii). The two genotypes did not differ in either cooking loss or percent moisture in any of the muscles compared. Title: Effect of callipyge gene on lamb growth, carcass characteristics, and meat quality Author: Srinivasan, Haribaskar Callipyge (CLPG, n=16) and normal (N, n=11) lambs were produced from Polypay dams and Dorset sires heterozygous for the CLPG gene to study the effects of the gene on growth and carcass and meat quality parameters. CLPG lambs had higher average daily gain than N lambs (0.26 vs 0.23 kg/day, p<.05); however, the CLPG gene did not affect feed efficiency. Lambs were slaughtered in three groups to achieve moderate uniformity in slaughter weight. At the time of slaughter, weights of head, pelt, and internal organs were recorded. Two leg muscles, two shoulder muscles, the longissimus dorsi muscle, and two loin chops cut 2.5 cm thick, were dissected from each carcass. CLPG lambs had a higher dressing percent (p<.01) and lighter head, pelt, liver (all p<.01), and kidney/pelvic fat (p<.05). CLPG lambs had less fat over 12th rib (p<.05) and larger ribeye area (p<.01). CLPG lambs had greater weights of Biceps femoris (42%, p<.05), Semimembranosus (34%, p<.01), Triceps brachii (20%, p<.05), longissimus dorsi muscle (29%, p<.01) and whole leg (6%, p<.05) than N lambs. All the dissected muscles from all carcasses and one whole leg from each ewe lamb carcasses (n=11) were cooked to an internal temperature of 70°C. CLPG carcasses produced higher Warner-Bratzler shear values for loin chops (4.79 vs 2.93 kg, p<.01), Biceps femoris (3.94 vs 2.92 kg, p<.05), Semimembranosus (4.75 vs 3.46 kg, p<.05) and Longissimus dorsi muscle (5.29 vs 3.4 kg, p<.01) than N lambs. However, no significant differences were detected in shear values for Biceps femoris (3.10 vs 3.04 kg) or Semimembranosus (3.77 vs 3.29 kg) when the muscles were dissected after roasting the whole leg. The CLPG gene also had no effect on the shear values for two dissected shoulder muscles (Deltoid and Triceps brachii). The two genotypes did not differ in either cooking loss or percent moisture in any of the muscles compared. Close

• 314. [Article] Turbidity in Prineville Reservoir as related to soils and hydrology

  Persistent levels of high turbidity in the outflow from the Prineville Reservoir led to development of relationships between watershed soils, land use, and resource management and water quality in the ...

  Citation × Citation Citation Abstract Copy Title: Turbidity in Prineville Reservoir as related to soils and hydrology Author: Silvernale, Clair Ellwood Persistent levels of high turbidity in the outflow from the Prineville Reservoir led to development of relationships between watershed soils, land use, and resource management and water quality in the Upper Crooked River, Central Oregon. Seven stations, strategically located for measurement of runoff volume and water sample collection, were established late in 1972. Six stations were on tributaries to the Crooked River; the seventh was on the main stream above the Prineville Reservoir. During runoff events, suspended sediment samples were obtained on each tributary above the confluence with the Crooked River. Greater stream sediment loads were associated with tributary watersheds under shrub-grass-juniper cover that have steeply rolling, dissected terrain with common rock outcrops. Those watersheds also have dominantly medium-textured, moderately deep soils. Steeper gradients are associated with these watersheds. Streams contributing high sediment loads were not necessarily those found to cause the long-term turbidity. This phenomenon was usually associated with those watersheds having a preponderance of soft, tuffaceous sedimentary rock. The results indicate major runoff events carry the greatest sediment loads to the reservoir and cause considerable turbidity. However, some turbidity-causing material is transported during smaller events as well. Freshets on watersheds with erodible soils cause turbidity during the convective storm season. Turbidity values in streams decreased between storm and runoff events, especially on forested watersheds. Sensitive watersheds (Camp Creek, TomVawn and Eagle Creek), with easily eroded soils,and specific reaches of the main channel, supply disproportionate amounts of material, causing long-term turbidity. X-ray diffraction analyses of suspended sediments, and the clay fraction of soil samples showed a predominance of smectites. Significant amounts of amorphous material were associated with the smectites in samples capable of creating long-term turbidity in the Prineville Reservoir. Field reconnissance of watershed land use and management indicated situations where domestic animal grazing, timber harvest and associated road building, and fire prevention practices which may unduly contribute to erosion and turbidity problems. Primary consideration of soil-hydrology relationships in land use planning and management is needed to reduce the severe erosion observed on certain tributaries. Particular attention should be directed toward minimizing erosion on soil with characteristics associated with long-term turbidity. Reservoir management and control should include recreational boating regulations to reduce shoreline turbulence. Limitations on boat draft, engine size, and total use will aid in reducing summertime shoreline turbidity. Recommended conservation and stabilization practices include: 1. Riparian fencing with controlled access for protection of stream bank soils, channel, and vegetation from external forces; 2. Retention of felled junipers, and continued felling, to extend soil moisture for germination and growth of grass; 3. Selective stream channel clearing to reduce debris-caused dams; 4. More awareness of soil-hydrology interrelationships by management agencies and private owners to better protect against turbidity-causing practices; and 5. Range management designed to maintain and improve grass cover and range condition overall. Title: Turbidity in Prineville Reservoir as related to soils and hydrology Author: Silvernale, Clair Ellwood Persistent levels of high turbidity in the outflow from the Prineville Reservoir led to development of relationships between watershed soils, land use, and resource management and water quality in the Upper Crooked River, Central Oregon. Seven stations, strategically located for measurement of runoff volume and water sample collection, were established late in 1972. Six stations were on tributaries to the Crooked River; the seventh was on the main stream above the Prineville Reservoir. During runoff events, suspended sediment samples were obtained on each tributary above the confluence with the Crooked River. Greater stream sediment loads were associated with tributary watersheds under shrub-grass-juniper cover that have steeply rolling, dissected terrain with common rock outcrops. Those watersheds also have dominantly medium-textured, moderately deep soils. Steeper gradients are associated with these watersheds. Streams contributing high sediment loads were not necessarily those found to cause the long-term turbidity. This phenomenon was usually associated with those watersheds having a preponderance of soft, tuffaceous sedimentary rock. The results indicate major runoff events carry the greatest sediment loads to the reservoir and cause considerable turbidity. However, some turbidity-causing material is transported during smaller events as well. Freshets on watersheds with erodible soils cause turbidity during the convective storm season. Turbidity values in streams decreased between storm and runoff events, especially on forested watersheds. Sensitive watersheds (Camp Creek, TomVawn and Eagle Creek), with easily eroded soils,and specific reaches of the main channel, supply disproportionate amounts of material, causing long-term turbidity. X-ray diffraction analyses of suspended sediments, and the clay fraction of soil samples showed a predominance of smectites. Significant amounts of amorphous material were associated with the smectites in samples capable of creating long-term turbidity in the Prineville Reservoir. Field reconnissance of watershed land use and management indicated situations where domestic animal grazing, timber harvest and associated road building, and fire prevention practices which may unduly contribute to erosion and turbidity problems. Primary consideration of soil-hydrology relationships in land use planning and management is needed to reduce the severe erosion observed on certain tributaries. Particular attention should be directed toward minimizing erosion on soil with characteristics associated with long-term turbidity. Reservoir management and control should include recreational boating regulations to reduce shoreline turbulence. Limitations on boat draft, engine size, and total use will aid in reducing summertime shoreline turbidity. Recommended conservation and stabilization practices include: 1. Riparian fencing with controlled access for protection of stream bank soils, channel, and vegetation from external forces; 2. Retention of felled junipers, and continued felling, to extend soil moisture for germination and growth of grass; 3. Selective stream channel clearing to reduce debris-caused dams; 4. More awareness of soil-hydrology interrelationships by management agencies and private owners to better protect against turbidity-causing practices; and 5. Range management designed to maintain and improve grass cover and range condition overall. Close

• 315. [Article] Benthic algal flora of four rivers of the middle Willamette River Basin

  Fresh-water benthic river algae were collected from selected sites in Willamette River tributaries; two sampling sites were in the Yamhill River system and four sampling sites were in the Santiam River ...

  Citation × Citation Citation Abstract Copy Title: Benthic algal flora of four rivers of the middle Willamette River Basin Author: Todd, Leona Esther Fresh-water benthic river algae were collected from selected sites in Willamette River tributaries; two sampling sites were in the Yamhill River system and four sampling sites were in the Santiam River system. Twelve samples were taken at each collection site in the Yamhill River system at approximately monthly intervals from June 1967 through June 1968. Fourteen samples were taken at all sampling sites, excepting one, in the Santiam River system at approximately monthly intervals from June 1967 through September 1968. A total of 24 genera of benthic algae other than diatoms were identified from the two river systems, 14 genera from the Yamhill River system and 22 genera from the Santiam River system. Six genera were common to both river systems, Anabaena, Oseillatoria, Schizothrix, Spirulina, Mougeotia and Oedogonium. Ten genera were found at only one of the collecting stations. By far, the most common genus was Schizothrix; it was found in 92 percent of the samples. The greatest diversity in the samples was found in the August 27, 1967 Santiam and September 2, 1967 Yamhill samples. The smallest number of genera were found in the March collections. A total of 14,986 individual diatoms were identified and counted. Sixty-two species of diatoms were found in this study; 55 were found in the Yamhill River system and 57 were found in the Santiam River system. Of the 13 species not found in common in the two collecting sites in the Yamhill River system, all excepting Fragilaria vaucheriae were found in very low numbers and in only a few samples. Those species not occurring in common in the Santiam River system were found in low numbers excepting for Cymbella affinis, C. ventricosa and Fragilaria capucina. The Yamhill River system and Santiam River system had 50 species in common and 24 species were collected at all six sampling stations. Statistical analyses of the diatom data were done by using *AIDONE and *AIDN computer programs. Comparative studies of diversity using Simpson's Diversity Index (SDI), dominance, Redundancy Index (R'), similarity, Similarity Index (SIMI) and niche breadth were made. Comparisons were made within and between rivers. The highest diversity and the lowest dominance occurred in the North Yamhill River; the highest dominance and the lowest diversity occurred at the Lebanon Dam on the South Santiam River. Stations on the Yamhill River system had a greater mean number of species per sample than the Santiam River system stations. In general, species with high niche breadth values in one river system also had high niche breadth values in the other system. A greater similarity within a river system than between the two river systems was shown. Title: Benthic algal flora of four rivers of the middle Willamette River Basin Author: Todd, Leona Esther Fresh-water benthic river algae were collected from selected sites in Willamette River tributaries; two sampling sites were in the Yamhill River system and four sampling sites were in the Santiam River system. Twelve samples were taken at each collection site in the Yamhill River system at approximately monthly intervals from June 1967 through June 1968. Fourteen samples were taken at all sampling sites, excepting one, in the Santiam River system at approximately monthly intervals from June 1967 through September 1968. A total of 24 genera of benthic algae other than diatoms were identified from the two river systems, 14 genera from the Yamhill River system and 22 genera from the Santiam River system. Six genera were common to both river systems, Anabaena, Oseillatoria, Schizothrix, Spirulina, Mougeotia and Oedogonium. Ten genera were found at only one of the collecting stations. By far, the most common genus was Schizothrix; it was found in 92 percent of the samples. The greatest diversity in the samples was found in the August 27, 1967 Santiam and September 2, 1967 Yamhill samples. The smallest number of genera were found in the March collections. A total of 14,986 individual diatoms were identified and counted. Sixty-two species of diatoms were found in this study; 55 were found in the Yamhill River system and 57 were found in the Santiam River system. Of the 13 species not found in common in the two collecting sites in the Yamhill River system, all excepting Fragilaria vaucheriae were found in very low numbers and in only a few samples. Those species not occurring in common in the Santiam River system were found in low numbers excepting for Cymbella affinis, C. ventricosa and Fragilaria capucina. The Yamhill River system and Santiam River system had 50 species in common and 24 species were collected at all six sampling stations. Statistical analyses of the diatom data were done by using *AIDONE and *AIDN computer programs. Comparative studies of diversity using Simpson's Diversity Index (SDI), dominance, Redundancy Index (R'), similarity, Similarity Index (SIMI) and niche breadth were made. Comparisons were made within and between rivers. The highest diversity and the lowest dominance occurred in the North Yamhill River; the highest dominance and the lowest diversity occurred at the Lebanon Dam on the South Santiam River. Stations on the Yamhill River system had a greater mean number of species per sample than the Santiam River system stations. In general, species with high niche breadth values in one river system also had high niche breadth values in the other system. A greater similarity within a river system than between the two river systems was shown. Close

• 316. [Article] Effects of Construction of an Infiltration Gallery Water Intake (Permit ID No. 00-32) on Cow Creek on Umpqua River Cutthroat Trout and Oregon Coast Coho Salmon : Biological Opinion

  In a January 26, 2000 letter, the Portland District Army Corps of Engineers (COE) requested Endangered Species Act (ESA) Section 7 informal consultation with the National Marine Fisheries Service (NMFS) ...

  Citation × Citation Citation Abstract Copy Title: Effects of Construction of an Infiltration Gallery Water Intake (Permit ID No. 00-32) on Cow Creek on Umpqua River Cutthroat Trout and Oregon Coast Coho Salmon : Biological Opinion In a January 26, 2000 letter, the Portland District Army Corps of Engineers (COE) requested Endangered Species Act (ESA) Section 7 informal consultation with the National Marine Fisheries Service (NMFS) on the proposed issuance of a Clean Water Act Section 404 permit (Permit ID No. 00-32) to allow an instream construction project. The applicant for this permit, the City of Glendale (City) proposes to construct an infiltration gallery-type municipal water intake in Cow Creek, a tributary of the South Umpqua River in Douglas County, Oregon. The new water intake, which would be buried beneath the bed of the creek, would replace an existing screened intake in the creek which has deteriorated and which is thought to have insufficient capacity. The COE has proposed conditions on the permit that would lessen the adverse effects of the proposed actions on aquatic organisms. In the January 26 letter, the COE determined that the Umpqua River (UR) cutthroat trout (Oncorhynchus clarki), listed as endangered under the ESA, and Oregon Coast (OC) coho salmon (O. kisutch), listed as threatened under the ESA, may occur within the project area, which has been proposed as critical habitat for these species. The COE also determined that these species may be affected by the proposed projects, but that individuals of the species would not be adversely affected. After review of the information provided by the COE and additional investigation, however, the NMFS concluded that more than a negligible likelihood of adverse effect to individuals of the listed species is likely because substantial in-water work is proposed during a period in which individuals of one or both species is likely to occur at and near the site. Based on this information, the COE agreed to modify its effect determination to likely to adversely affect. Title: Effects of Construction of an Infiltration Gallery Water Intake (Permit ID No. 00-32) on Cow Creek on Umpqua River Cutthroat Trout and Oregon Coast Coho Salmon : Biological Opinion In a January 26, 2000 letter, the Portland District Army Corps of Engineers (COE) requested Endangered Species Act (ESA) Section 7 informal consultation with the National Marine Fisheries Service (NMFS) on the proposed issuance of a Clean Water Act Section 404 permit (Permit ID No. 00-32) to allow an instream construction project. The applicant for this permit, the City of Glendale (City) proposes to construct an infiltration gallery-type municipal water intake in Cow Creek, a tributary of the South Umpqua River in Douglas County, Oregon. The new water intake, which would be buried beneath the bed of the creek, would replace an existing screened intake in the creek which has deteriorated and which is thought to have insufficient capacity. The COE has proposed conditions on the permit that would lessen the adverse effects of the proposed actions on aquatic organisms. In the January 26 letter, the COE determined that the Umpqua River (UR) cutthroat trout (Oncorhynchus clarki), listed as endangered under the ESA, and Oregon Coast (OC) coho salmon (O. kisutch), listed as threatened under the ESA, may occur within the project area, which has been proposed as critical habitat for these species. The COE also determined that these species may be affected by the proposed projects, but that individuals of the species would not be adversely affected. After review of the information provided by the COE and additional investigation, however, the NMFS concluded that more than a negligible likelihood of adverse effect to individuals of the listed species is likely because substantial in-water work is proposed during a period in which individuals of one or both species is likely to occur at and near the site. Based on this information, the COE agreed to modify its effect determination to likely to adversely affect. Close

• 317. [Article] The geology and stratigraphy of the Tertiary volcanic and volcaniclastic rocks, with special emphasis on the Deschutes Formation, from Lake Simtustus to Madras in central Oregon

  A sequence of volcanic, volcaniclastic, and epiclastic deposits from Oligocene to Recent age are exposed in the region from Lake Simtustus to Madras in central Oregon. The epiclastic sediments of the Oligocene ...

  Citation × Citation Citation Abstract Copy Title: The geology and stratigraphy of the Tertiary volcanic and volcaniclastic rocks, with special emphasis on the Deschutes Formation, from Lake Simtustus to Madras in central Oregon Author: Jay, Jeremy Barth A sequence of volcanic, volcaniclastic, and epiclastic deposits from Oligocene to Recent age are exposed in the region from Lake Simtustus to Madras in central Oregon. The epiclastic sediments of the Oligocene John Day Formation are unconformably overlain by two flows of the middle Miocene Columbia River Basalt Group. The upper Miocene and lower Pliocene Deschutes Formation generally overlies the Columbia River Basalt. The Deschutes Formation includes ash flows, pumice and ash falls, lava flows and epiclastic deposits. An ashflow tuff with a composition similar to other Deschutes ash flows occurs between flows of Columbia River basalt suggesting that the formations interfinger. The two flows of Columbia River basalt have compositions typical of the Prineville Chemical Type. The flows contain an average of 1.24 weight percent P2051 and K20 is high compared to other types of Columbia River basalt. The Columbia River basalt and underlying rocks have been moderately deformed, producing broad anticlines and synclines and normal faults with small displacement. Northwest of Madras, the Columbia River basalt dips three or four degrees to the southeast. The Deschutes Formation and overlying rocks are generally flat lying and undeformed. No faults were found extending into the Deschutes deposits. The Pelton Basalt member is an 80 to 150 foot thick unit of tholeiitic basalt that occurs near the base of the Deschutes Formation. It contains numerous discontinuous flow units which represent separate lobes of a compound lava flow. No interbeds or paleosols between flow units were found. The basalt is probably the result of a single prolonged eruption. Six intraformational lava flows occur interstratified with volcaniclastic and epiclastic deposits. Five of these flows are basalt; one flow is basaltic andesite. The Deschutes volcaniclastic rocks generally occur in a four hundred foot thick interval above the Pelton Member and below rimforming basalt lavas. The best exposures of these deposits are at the Vanora Cliff and at the cliff on the north side of the mouth of Willow Creek. Rocks in both of these areas are exposed as the result of large landslides. The ash-flow tuffs range in composition from dacite to rhyolite and range from three to sixty feet thick. The deposits generally have restricted areas of exposure. The strikes of paleochannels filled by ash flows and the orientation of the long axes of clasts in underlying fluvial conglomerates indicate a west or southwest provenance for these deposits. Seven lithic-rich laharic-breccia deposits occur interstratified with the ash flows and epiclastic deposits. The laharic breccias are the most resistant and extensive volcaniclastic rocks in the mapped area. In certain outcrops, the breccias consist of as much as seventy percent angular to subrounded lithic clasts suspended in a finegrained matrix of glass shards. The deposits are more numerous, thicker, and more poorly sorted to the north and northwest indicating a provenance to the northwest. Many features of the deposits are similar to volcanic lahars but other characteristics indicate that the materials were subjected to temperatures above the Curie point of the clasts. Some of these units might have been produced by a combination of fluvial materials and a hot pyroclastic flow. A widespread sheet of tholeiitic basalt caps the Deschutes Formation. Similarity between eight chemical analyses, constant phenocryst mineralogy, and uniform normal paleomagnetic polarity of samples from Binder's Canyon to Round Butte Dam suggest that the rimforming flow is a single sheet of lava that originally covered the mapped area. Round Butte cinder cone and lava flow are the youngest Deschutes Formation deposits in the mapped area. The Round Butte deposits have a composition similar to other intraformational lavas and therefore represent a continuation of the volcanism that has occurred throughout the late Miocene and early Pliocene in the Deschutes Basin. Title: The geology and stratigraphy of the Tertiary volcanic and volcaniclastic rocks, with special emphasis on the Deschutes Formation, from Lake Simtustus to Madras in central Oregon Author: Jay, Jeremy Barth A sequence of volcanic, volcaniclastic, and epiclastic deposits from Oligocene to Recent age are exposed in the region from Lake Simtustus to Madras in central Oregon. The epiclastic sediments of the Oligocene John Day Formation are unconformably overlain by two flows of the middle Miocene Columbia River Basalt Group. The upper Miocene and lower Pliocene Deschutes Formation generally overlies the Columbia River Basalt. The Deschutes Formation includes ash flows, pumice and ash falls, lava flows and epiclastic deposits. An ashflow tuff with a composition similar to other Deschutes ash flows occurs between flows of Columbia River basalt suggesting that the formations interfinger. The two flows of Columbia River basalt have compositions typical of the Prineville Chemical Type. The flows contain an average of 1.24 weight percent P2051 and K20 is high compared to other types of Columbia River basalt. The Columbia River basalt and underlying rocks have been moderately deformed, producing broad anticlines and synclines and normal faults with small displacement. Northwest of Madras, the Columbia River basalt dips three or four degrees to the southeast. The Deschutes Formation and overlying rocks are generally flat lying and undeformed. No faults were found extending into the Deschutes deposits. The Pelton Basalt member is an 80 to 150 foot thick unit of tholeiitic basalt that occurs near the base of the Deschutes Formation. It contains numerous discontinuous flow units which represent separate lobes of a compound lava flow. No interbeds or paleosols between flow units were found. The basalt is probably the result of a single prolonged eruption. Six intraformational lava flows occur interstratified with volcaniclastic and epiclastic deposits. Five of these flows are basalt; one flow is basaltic andesite. The Deschutes volcaniclastic rocks generally occur in a four hundred foot thick interval above the Pelton Member and below rimforming basalt lavas. The best exposures of these deposits are at the Vanora Cliff and at the cliff on the north side of the mouth of Willow Creek. Rocks in both of these areas are exposed as the result of large landslides. The ash-flow tuffs range in composition from dacite to rhyolite and range from three to sixty feet thick. The deposits generally have restricted areas of exposure. The strikes of paleochannels filled by ash flows and the orientation of the long axes of clasts in underlying fluvial conglomerates indicate a west or southwest provenance for these deposits. Seven lithic-rich laharic-breccia deposits occur interstratified with the ash flows and epiclastic deposits. The laharic breccias are the most resistant and extensive volcaniclastic rocks in the mapped area. In certain outcrops, the breccias consist of as much as seventy percent angular to subrounded lithic clasts suspended in a finegrained matrix of glass shards. The deposits are more numerous, thicker, and more poorly sorted to the north and northwest indicating a provenance to the northwest. Many features of the deposits are similar to volcanic lahars but other characteristics indicate that the materials were subjected to temperatures above the Curie point of the clasts. Some of these units might have been produced by a combination of fluvial materials and a hot pyroclastic flow. A widespread sheet of tholeiitic basalt caps the Deschutes Formation. Similarity between eight chemical analyses, constant phenocryst mineralogy, and uniform normal paleomagnetic polarity of samples from Binder's Canyon to Round Butte Dam suggest that the rimforming flow is a single sheet of lava that originally covered the mapped area. Round Butte cinder cone and lava flow are the youngest Deschutes Formation deposits in the mapped area. The Round Butte deposits have a composition similar to other intraformational lavas and therefore represent a continuation of the volcanism that has occurred throughout the late Miocene and early Pliocene in the Deschutes Basin. Close

• 318. [Article] A bioeconomic analysis of altering instream flows anadromous fish production and competing demands for water in the John Day River basin, Oregon

  The growing demand for water in the arid regions of the West increases the need for optimal allocation of water among competing uses. An efficient allocation of water between instream and out-of-stream uses ...

  Citation × Citation Citation Abstract Copy Title: A bioeconomic analysis of altering instream flows anadromous fish production and competing demands for water in the John Day River basin, Oregon Author: Johnson, Neal S. The growing demand for water in the arid regions of the West increases the need for optimal allocation of water among competing uses. An efficient allocation of water between instream and out-of-stream uses has been impeded by institutional constraints and the scarcity of information regarding instream flow benefits. The objectives of this thesis were to provide preliminary economic data on the value of instream water in "producing" recreational fishing and to examine the effect of forestry, agriculture, and livestock practices on temporal streamflow patterns and anadromous fish production. The steelhead trout (Salmo gairdneri) sport fishery within the John Day River basin in north-central Oregon provided the setting for this research. The interdisciplinary methodology employed in estimating the marginal value of water with respect to steelhead production consisted of two tasks. The first task involved valuing a marginal change in the quality of the steelhead recreational fishery. The contingent valuation method (CVM) was selected for this purpose. Both open- and closed-ended willingness-to-pay (WTP) questions were included in a questionnaire administered to John Day River steelhead anglers during the 1986/87 steelhead fishing season. Survey data were analyzed to arrive at individual and aggregate bid functions relating WTP to expected angling success rates. Results indicate that, under current conditions, the average angler is willing to pay approximately $7.20 to catch an additional steelhead. The second task of the instream water valuation methodology was directed at deriving a streamflow/steelhead production relationship. By including variables influencing steelhead production in a Ricker stock-recruitment model, it was possible to develop a model which could be estimated using linear regression techniques. Some difficulty arose, however, with interpretation of the model due to the unavailability of cohort escapement data and the subsequent use of standing crop data. While possibly masking the true magnitude of streamflow's effect on fish production, this drawback was not deemed limiting within the general context of the interdisciplinary methodology. Results of the biological model conformed to a priori expectations. Increases in summer and winter streamflows led to increased steelhead survival, whereas higher spring flows increased mortality levels. Other results indicate that the John Day Dam was responsible for a 31.5 percent decline in the population index for the 1969-1983 period. Combining the economic and biological results into one equation yielded an estimate of the marginal value of summer instream water in "producing" recreational steelhead angling. Similar equations were developed for winter and spring flows. The marginal value of water in producing recreational steelhead fishing within the John Day basin was estimated at $0.56 per acre-foot for summer flows, $0.046 for winter flows, and -$0.075 for spring flows. By including out-of-basin benefits, these values increased to $2.26, $0.19, and -$0.30, respectively. In comparison, water's value in irrigation within the John Day basin has been estimated at between $10 to $24 per acre-foot. However, nonuse values of steelhead, as well as the increased production of other fish species (such as spring chinook salmon) were not included in the instream water values. In addition, no attempt was made at valuing instream water's contribution to boating, camping, or other benefit-producing activities. A secondary objective of this thesis was to briefly examine the possible benefits accruing to other instream and out-of-stream users due to an alteration in streamflow patterns. In addition, the impact of activities by other resource users -- namely forestry, agriculture, and livestock production --on anadromous fish production was reviewed. Improper management practices by these activities can negatively impact the aquatic and riparian ecosystems. While no firm conclusions were drawn, it appears the quality of these ecosystems, as opposed to the amount of streamflow, has the largest marginal impact on anadromous fish populations. Title: A bioeconomic analysis of altering instream flows anadromous fish production and competing demands for water in the John Day River basin, Oregon Author: Johnson, Neal S. The growing demand for water in the arid regions of the West increases the need for optimal allocation of water among competing uses. An efficient allocation of water between instream and out-of-stream uses has been impeded by institutional constraints and the scarcity of information regarding instream flow benefits. The objectives of this thesis were to provide preliminary economic data on the value of instream water in "producing" recreational fishing and to examine the effect of forestry, agriculture, and livestock practices on temporal streamflow patterns and anadromous fish production. The steelhead trout (Salmo gairdneri) sport fishery within the John Day River basin in north-central Oregon provided the setting for this research. The interdisciplinary methodology employed in estimating the marginal value of water with respect to steelhead production consisted of two tasks. The first task involved valuing a marginal change in the quality of the steelhead recreational fishery. The contingent valuation method (CVM) was selected for this purpose. Both open- and closed-ended willingness-to-pay (WTP) questions were included in a questionnaire administered to John Day River steelhead anglers during the 1986/87 steelhead fishing season. Survey data were analyzed to arrive at individual and aggregate bid functions relating WTP to expected angling success rates. Results indicate that, under current conditions, the average angler is willing to pay approximately $7.20 to catch an additional steelhead. The second task of the instream water valuation methodology was directed at deriving a streamflow/steelhead production relationship. By including variables influencing steelhead production in a Ricker stock-recruitment model, it was possible to develop a model which could be estimated using linear regression techniques. Some difficulty arose, however, with interpretation of the model due to the unavailability of cohort escapement data and the subsequent use of standing crop data. While possibly masking the true magnitude of streamflow's effect on fish production, this drawback was not deemed limiting within the general context of the interdisciplinary methodology. Results of the biological model conformed to a priori expectations. Increases in summer and winter streamflows led to increased steelhead survival, whereas higher spring flows increased mortality levels. Other results indicate that the John Day Dam was responsible for a 31.5 percent decline in the population index for the 1969-1983 period. Combining the economic and biological results into one equation yielded an estimate of the marginal value of summer instream water in "producing" recreational steelhead angling. Similar equations were developed for winter and spring flows. The marginal value of water in producing recreational steelhead fishing within the John Day basin was estimated at $0.56 per acre-foot for summer flows, $0.046 for winter flows, and -$0.075 for spring flows. By including out-of-basin benefits, these values increased to $2.26, $0.19, and -$0.30, respectively. In comparison, water's value in irrigation within the John Day basin has been estimated at between $10 to $24 per acre-foot. However, nonuse values of steelhead, as well as the increased production of other fish species (such as spring chinook salmon) were not included in the instream water values. In addition, no attempt was made at valuing instream water's contribution to boating, camping, or other benefit-producing activities. A secondary objective of this thesis was to briefly examine the possible benefits accruing to other instream and out-of-stream users due to an alteration in streamflow patterns. In addition, the impact of activities by other resource users -- namely forestry, agriculture, and livestock production --on anadromous fish production was reviewed. Improper management practices by these activities can negatively impact the aquatic and riparian ecosystems. While no firm conclusions were drawn, it appears the quality of these ecosystems, as opposed to the amount of streamflow, has the largest marginal impact on anadromous fish populations. Close

• 319. [Article] Gonadotropins in pituitaries of inbred and linecross beef bulls and effects of irradiation of mammalian pituitary glands on their ability to induce in vitro ovulation of frog ovaries

  There were two studies involved in the thesis research. In the first study, variation in the amount of adenohypophysis gonadotropins among 22 individual beef bulls were investigated. These bulls represented ...

  Citation × Citation Citation Abstract Copy Title: Gonadotropins in pituitaries of inbred and linecross beef bulls and effects of irradiation of mammalian pituitary glands on their ability to induce in vitro ovulation of frog ovaries Author: North, Warren Arthur There were two studies involved in the thesis research. In the first study, variation in the amount of adenohypophysis gonadotropins among 22 individual beef bulls were investigated. These bulls represented four inbred lines, and six linecrosses. The bulls were raised in the Oregon State University purebred herd. The bulls were slaughtered at approximately 1000 pounds live weight. The pituitaries were removed, weighed, individually identified, sealed in glass vials, and frozen at -20°C. until needed for bioassay. Assay material was prepared by dissecting the anterior lobe from the other pituitary material and then crushing the adenohypophysis in a hand operated tissue grinder. Immature male and female mice were used to assay for gonadotropic potency. T-test values showed all bull pituitaries to contain a significant amont of both follicle stimulating hormone and luteinizing hormone when the pituitary-treated mice were compared with control mice. When the Hereford inbred lines of cattle were compared with one another no significant differences were found for gonadotropic potency. However, when the inbred Angus line was compared with each of the inbred Hereford lines, one of the inbred Hereford lines had significantly greater luteinizing hormone activity than the inbred Angus, and another inbred Hereford line had a significantly greater amount of follicle stimulating hormone activity than the inbred Angus. One of the linecrosses had significantly greater luteinizing hormone potency than all four inbred lines, and a different linecross had a significantly greater amount of follicle stimulating hormone potency than three of the four inbred lines. However, one inbred Hereford line had a significantly greater amount of luteinizing hormone than two of the Hereford linecrosses. A comparison of linecrosses showed many significant variations in one or the other gonadotropic potency. It was noted that wherever a significant difference existed, the greater potency for one or the other gonadotropin favored the linecross that had either a sire or dam of inbred Lionheart parentage. In the second study, effects of x-irradiation delivered at rates of 0, 1000, 2000, 3000, 4000, and 5000 r. to excised beef cattle, sheep, and rabbit pituitaries and their subsequent in vitro gonadotropic potency were investigated by use of grass frog ovarian fragments. The pituitary material was added to test tubes at levels of 150, 125, 100, 75, 50, 25, 10, 5, and 1 mg. per test tube. A modified (calcium free) Holtfreter solution was added to each test tube bringing the total volume to 10 ml. in each test tube. A grass frog ovarian fragment was placed in the incubation medium for 48 hours. Following incubation the number of released eggs were recorded. Origin of the ovarian fragments were identified as to ovary and position. Ovulation percentage was affected by the mammalian species from which the pituitaries came, the level of irradiation, and the amount of pituitary added to each culturing test tube. One hundred twenty-five mg. of non-irradiated sheep pituitary was able to induce a very slight amount of frog ovulation. However, sheep pituitary which received 2000 r. induced a much better ovulation percentage with 75 and 100 mg. pituitary material. When the beef cattle pituitary was delivered 1000 r. the ovulation rate remained slight, but ovulation occurred at the 100, 125, and 150 mg. levels. Irradiation levels greater than 2000 r. compared with the 2000 r. level had a depressing effect on ovulation rate. When comparing all rates of irradiation and all levels of rabbit pituitary, 25 mg. of rabbit pituitary which had received 3000 r. appeared best. At this point 40.3 percent ovulation occurred. An analysis of variance was run for all three mammalian species for the radiation rate, the pituitary level, ovary location of the frog, and position of the frog ovarian fragment. The analysis of variance showed that results are not influenced by either of the two ovaries nor by the position of the fragments. The results are significantly affected by the level of pituitary used and the amount of irradiation delivered to the mammalian pituitary. Title: Gonadotropins in pituitaries of inbred and linecross beef bulls and effects of irradiation of mammalian pituitary glands on their ability to induce in vitro ovulation of frog ovaries Author: North, Warren Arthur There were two studies involved in the thesis research. In the first study, variation in the amount of adenohypophysis gonadotropins among 22 individual beef bulls were investigated. These bulls represented four inbred lines, and six linecrosses. The bulls were raised in the Oregon State University purebred herd. The bulls were slaughtered at approximately 1000 pounds live weight. The pituitaries were removed, weighed, individually identified, sealed in glass vials, and frozen at -20°C. until needed for bioassay. Assay material was prepared by dissecting the anterior lobe from the other pituitary material and then crushing the adenohypophysis in a hand operated tissue grinder. Immature male and female mice were used to assay for gonadotropic potency. T-test values showed all bull pituitaries to contain a significant amont of both follicle stimulating hormone and luteinizing hormone when the pituitary-treated mice were compared with control mice. When the Hereford inbred lines of cattle were compared with one another no significant differences were found for gonadotropic potency. However, when the inbred Angus line was compared with each of the inbred Hereford lines, one of the inbred Hereford lines had significantly greater luteinizing hormone activity than the inbred Angus, and another inbred Hereford line had a significantly greater amount of follicle stimulating hormone activity than the inbred Angus. One of the linecrosses had significantly greater luteinizing hormone potency than all four inbred lines, and a different linecross had a significantly greater amount of follicle stimulating hormone potency than three of the four inbred lines. However, one inbred Hereford line had a significantly greater amount of luteinizing hormone than two of the Hereford linecrosses. A comparison of linecrosses showed many significant variations in one or the other gonadotropic potency. It was noted that wherever a significant difference existed, the greater potency for one or the other gonadotropin favored the linecross that had either a sire or dam of inbred Lionheart parentage. In the second study, effects of x-irradiation delivered at rates of 0, 1000, 2000, 3000, 4000, and 5000 r. to excised beef cattle, sheep, and rabbit pituitaries and their subsequent in vitro gonadotropic potency were investigated by use of grass frog ovarian fragments. The pituitary material was added to test tubes at levels of 150, 125, 100, 75, 50, 25, 10, 5, and 1 mg. per test tube. A modified (calcium free) Holtfreter solution was added to each test tube bringing the total volume to 10 ml. in each test tube. A grass frog ovarian fragment was placed in the incubation medium for 48 hours. Following incubation the number of released eggs were recorded. Origin of the ovarian fragments were identified as to ovary and position. Ovulation percentage was affected by the mammalian species from which the pituitaries came, the level of irradiation, and the amount of pituitary added to each culturing test tube. One hundred twenty-five mg. of non-irradiated sheep pituitary was able to induce a very slight amount of frog ovulation. However, sheep pituitary which received 2000 r. induced a much better ovulation percentage with 75 and 100 mg. pituitary material. When the beef cattle pituitary was delivered 1000 r. the ovulation rate remained slight, but ovulation occurred at the 100, 125, and 150 mg. levels. Irradiation levels greater than 2000 r. compared with the 2000 r. level had a depressing effect on ovulation rate. When comparing all rates of irradiation and all levels of rabbit pituitary, 25 mg. of rabbit pituitary which had received 3000 r. appeared best. At this point 40.3 percent ovulation occurred. An analysis of variance was run for all three mammalian species for the radiation rate, the pituitary level, ovary location of the frog, and position of the frog ovarian fragment. The analysis of variance showed that results are not influenced by either of the two ovaries nor by the position of the fragments. The results are significantly affected by the level of pituitary used and the amount of irradiation delivered to the mammalian pituitary. Close

• 320. [Article] Synchronization of estrus and subsequent conception rates in dairy heifers and rats following treatment with melengestrol acetate

  Two experiments were conducted to study the effects of melengestrol acetate (MGA) on inhibition of estrus, post-treatment conception rates in heifers and rats, and MGA given during gestation on the reproductive ...

  Citation × Citation Citation Abstract Copy Title: Synchronization of estrus and subsequent conception rates in dairy heifers and rats following treatment with melengestrol acetate Author: Chakraborty, Prabir Kumar, 1936- Two experiments were conducted to study the effects of melengestrol acetate (MGA) on inhibition of estrus, post-treatment conception rates in heifers and rats, and MGA given during gestation on the reproductive performance in rats. MGA was administered orally to Holstein heifers and by subcutaneous injection to Sprague- Dawley rats. Twenty-four Holstein heifers (Experiment 1) were used in the study and each animal in the treatment group (12 heifers) received 1.0 mg. of MGA daily for 14 consecutive days. The treatment was initiated irrespective of the stage of the estrous cycle. Following withdrawal of treatment, one-half of the animals from each of the control and treatment groups were inseminated twice at the first post-treatment estrus at approximately 12-hour intervals, the other half received single inseminations. Conception rates were based on pregnancy diagnosis at 45 or more days following the last service. Estrus was inhibited during the period of treatment in all animals in the treatment group. Withdrawal of treatment resulted in an effective synchronization of estrus and ovulation,and 83.3% of the treated animals were in heat within a 48-hour period. The difference between the number of MGA treated animals showing estrus within 3-6 days following treatment withdrawal and the number of control animals in heat during the corresponding period of time, was highly significant (P < 0.005). Treatment resulted in a significantly (P < 0.05) lower conception at the first post-treatment insemination for the treatment group compared to that of the controls (8.33 vs. 58.33 %). No significant difference in conception rates was observed between single and double inseminations at the first estrus following treatment withdrawal. Conception rate for the treatment group at the second estrus following treatment (54.54%) was similar to that of the control animals at the first estrus following cessation of treatment (58.33%). Although an equal number of animals from each group conceived following two or more services, the average number of services per conception for the treatment group (2.64) was significantly higher (P < 0.05) than that for the control group (1.54). Forty-eight sexually mature Sprague-Dawley female rats with body weights ranging from 225 to 260 gm. were used in the rat study (Experiment 2). The animals were assigned at random to three treatment groups. Two of the groups received an initial daily treatment of 0.01 mg. and 0.10 mg. of MGA (in 0.1 ml. of propylene glycol) for seven days, respectively. The control group received 0.10 ml. of propylene glycol only, for the same duration. Following withdrawal of treatment, the animals were placed in breeding cages and allowed to mate during a breeding period of ten days, each cage contained four female and two male rats. Starting on day 7 of pregnancy, one-half of the animals from each group were injected daily with 0.10 mg. of MGA for 14 consecutive days. Cyclic changes in the vaginal cytology was not inhibited in control animals and the group of animals receiving 0.01 mg. of MGA daily during the treatment period. Inhibition of cyclic changes during the period of treatment in all animals receiving daily injections of 0.10 mg. of MGA were observed. The animals in this group showed estrus on an average of 4.46 days following withdrawal of treatment. No significant differences in conception rates among the groups were detected following a breeding period of ten days. Analysis of data on growth response in the dams and their reproductive performance did not indicate any significant interaction between initial and post-breeding treatments. Post-breeding treatment resulted in significant (P < 0.01) depressing effects in mean weight gains during experimentation and an increase in mean gestation length as compared to controls. Animals receiving treatment during gestation also had a significantly lower (P < 0.05) number of pups per litter and a significantly lower (P < 0.01) mean litter weight. Pups from mothers receiving treatment during gestation had significantly lower (P < 0.01) birth weights and also registered a significantly higher (P < 0.01) percent mortality compared to controls. Title: Synchronization of estrus and subsequent conception rates in dairy heifers and rats following treatment with melengestrol acetate Author: Chakraborty, Prabir Kumar, 1936- Two experiments were conducted to study the effects of melengestrol acetate (MGA) on inhibition of estrus, post-treatment conception rates in heifers and rats, and MGA given during gestation on the reproductive performance in rats. MGA was administered orally to Holstein heifers and by subcutaneous injection to Sprague- Dawley rats. Twenty-four Holstein heifers (Experiment 1) were used in the study and each animal in the treatment group (12 heifers) received 1.0 mg. of MGA daily for 14 consecutive days. The treatment was initiated irrespective of the stage of the estrous cycle. Following withdrawal of treatment, one-half of the animals from each of the control and treatment groups were inseminated twice at the first post-treatment estrus at approximately 12-hour intervals, the other half received single inseminations. Conception rates were based on pregnancy diagnosis at 45 or more days following the last service. Estrus was inhibited during the period of treatment in all animals in the treatment group. Withdrawal of treatment resulted in an effective synchronization of estrus and ovulation,and 83.3% of the treated animals were in heat within a 48-hour period. The difference between the number of MGA treated animals showing estrus within 3-6 days following treatment withdrawal and the number of control animals in heat during the corresponding period of time, was highly significant (P < 0.005). Treatment resulted in a significantly (P < 0.05) lower conception at the first post-treatment insemination for the treatment group compared to that of the controls (8.33 vs. 58.33 %). No significant difference in conception rates was observed between single and double inseminations at the first estrus following treatment withdrawal. Conception rate for the treatment group at the second estrus following treatment (54.54%) was similar to that of the control animals at the first estrus following cessation of treatment (58.33%). Although an equal number of animals from each group conceived following two or more services, the average number of services per conception for the treatment group (2.64) was significantly higher (P < 0.05) than that for the control group (1.54). Forty-eight sexually mature Sprague-Dawley female rats with body weights ranging from 225 to 260 gm. were used in the rat study (Experiment 2). The animals were assigned at random to three treatment groups. Two of the groups received an initial daily treatment of 0.01 mg. and 0.10 mg. of MGA (in 0.1 ml. of propylene glycol) for seven days, respectively. The control group received 0.10 ml. of propylene glycol only, for the same duration. Following withdrawal of treatment, the animals were placed in breeding cages and allowed to mate during a breeding period of ten days, each cage contained four female and two male rats. Starting on day 7 of pregnancy, one-half of the animals from each group were injected daily with 0.10 mg. of MGA for 14 consecutive days. Cyclic changes in the vaginal cytology was not inhibited in control animals and the group of animals receiving 0.01 mg. of MGA daily during the treatment period. Inhibition of cyclic changes during the period of treatment in all animals receiving daily injections of 0.10 mg. of MGA were observed. The animals in this group showed estrus on an average of 4.46 days following withdrawal of treatment. No significant differences in conception rates among the groups were detected following a breeding period of ten days. Analysis of data on growth response in the dams and their reproductive performance did not indicate any significant interaction between initial and post-breeding treatments. Post-breeding treatment resulted in significant (P < 0.01) depressing effects in mean weight gains during experimentation and an increase in mean gestation length as compared to controls. Animals receiving treatment during gestation also had a significantly lower (P < 0.05) number of pups per litter and a significantly lower (P < 0.01) mean litter weight. Pups from mothers receiving treatment during gestation had significantly lower (P < 0.01) birth weights and also registered a significantly higher (P < 0.01) percent mortality compared to controls. Close