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Articles 2431 - 2460 of 2597

Full-Text Articles in Agricultural Science

Division S-4-Soil Fertility And Plant Nutrition: Recovery Of Fertilizer Nitrogen By Wheat As Affected By Fallow Method, J. F. Power, Wallace Wilhelm, John W. Doran Nov 1986

Division S-4-Soil Fertility And Plant Nutrition: Recovery Of Fertilizer Nitrogen By Wheat As Affected By Fallow Method, J. F. Power, Wallace Wilhelm, John W. Doran

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The fate of fertilizer N applied to crops is of both environmental and economic concern. To follow fertilizer N recovery in western Nebraska, depleted-15N NH4NO3 was surface broadcast in April on winter wheat (Triticum aestivum L.) growing on plots fallowed the previous year by plowing, subtillage, and no-till. Quantities of labeled N taken up by the growing crop, in the upper 100 mm of soil as inorganic N, and in both visible and partially decomposed crop residues, were followed on two sets of plots through the crop-fallow-crop sequence (approximately 117 weeks). About 16 to …


Uptake Of Nitrogen From Soil, Fertilizer, And Crop Residues By No-Till Corn And Soybean, J. F. Power, John W. Doran, Wallace Wilhelm Nov 1986

Uptake Of Nitrogen From Soil, Fertilizer, And Crop Residues By No-Till Corn And Soybean, J. F. Power, John W. Doran, Wallace Wilhelm

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The relative availability of nitrogen (N) from indigenous soil organic N, immobilized fertilizer N, currently applied fertilizer N, and crop residues is largely unknown. A non-irrigated experiment was conducted on a silty clay loam at Lincoln, NE, with both continuous soybean [Glycine max (L.) Merr.] and corn (Zea mays L.), in which crops were produced with no tillage after surface application of 0, 0.5,1.0, or 1.5 times the quantity of aboveground crop residue produced the previous year. In 1980 and 1981, depleted 15N NH4NO3 (at 45 kg N ha-1) and crop residues …


Crop Residue Effects On Soil Environment And Dryland Maize And Soya Bean Production, J. F. Power, Wallace Wilhelm, J. W. Doran Nov 1986

Crop Residue Effects On Soil Environment And Dryland Maize And Soya Bean Production, J. F. Power, Wallace Wilhelm, J. W. Doran

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The research reported here provides data on the effects of crop residues on the surface of no-till soil upon the soil environment and resulting biological activity, including crop growth. For maize (Zea mays L.) and soya bean [Glycine max (L.) Merr.] production in eastern Nebraska, U.S.A. (4 years of data), increasing crop residue rate decreased maximum soil temperatures at the soil surface by at least 5°C, and generally increased soil water storage by at least 50 mm. Availability and uptake of nitrogen from the soil organic matter and applied fertilizers (and for soya bean from decomposition of crop …


Endocrine Changes During Restoration Of Estrous Cycles Following Induction Of Anestrus By Restricted Nutrient Intake In Beef Heifers, K. Imakawa, M. L. Day, M. Garcia-Winder, D. D. Zalesky, Roger J. Kittok, B. D. Schanbacher, J. E. Kinder Jan 1986

Endocrine Changes During Restoration Of Estrous Cycles Following Induction Of Anestrus By Restricted Nutrient Intake In Beef Heifers, K. Imakawa, M. L. Day, M. Garcia-Winder, D. D. Zalesky, Roger J. Kittok, B. D. Schanbacher, J. E. Kinder

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The working hypotheses in this experiment were: 1) that ovarian estradiol would inhibit luteinizing hormone (LH) secretion in heifers that were anestrus as a result of restricted dietary energy intake and 2) the responsiveness of LH secretion to estradiol negative feedback would decrease during the period when restoration of estrous cycles occurred following feeding of diets adequate in energy. Fifteen heifers weighing 341 ± 12 (mean ± SE) kg were fed a diet containing 50% of the energy required for maintenance until 40 to 50 d following cessation of estrous cycles. Heifers were assigned to intact control (C, n = …


Bacteroids Are Stable During Dark-Induced Senescence Of Soybean Root Nodules, Gautam Sarath, Nancy E. Pfeiffer, C.S. Sodhi, Fred W. Wagner Jan 1986

Bacteroids Are Stable During Dark-Induced Senescence Of Soybean Root Nodules, Gautam Sarath, Nancy E. Pfeiffer, C.S. Sodhi, Fred W. Wagner

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Physiological and biochemical markers of metabolic competence were assayed in bacteroids isolated from root nodules of control, dark-stressed, and recovered plants of Glycine max Merr. cv `Woodworth.' Nitrogenase-dependent acetylene reduction by the whole plant decreased to 8% of control rates after 4 days of dark stress and could not be detected in plants dark stressed for 8 days. However, in bacteroids isolated anaerobically, almost 50% of initial acetylene reduction activity remained after 4 days of dark stress but was totally lost after 8 days of dark stress. Bacteroid acetylene reduction activity recovered faster than whole plant acetylene reduction activity when …


Effect Of Active Immunization Against Lhrh Or Lh In Boars: Reproductive Consequences And Performance Traits, R. E. Falvo, V. Chandrashekar, R. D. Arthur, A. R. Kuenstler, T. Hasson, C. Awcniyi, B. D. Schanbacher Jan 1986

Effect Of Active Immunization Against Lhrh Or Lh In Boars: Reproductive Consequences And Performance Traits, R. E. Falvo, V. Chandrashekar, R. D. Arthur, A. R. Kuenstler, T. Hasson, C. Awcniyi, B. D. Schanbacher

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Forty crossbred boars were equally divided into eight groups at birth. Four groups were immunized (200 μg/boar) at 12 wk of age against either luteinizing hormone-releasing hormone (LHRH) conjugated to human serum globulin (LHRH-hSG) in complete Freund's adjuvant (CFA), LHRH-hSG in muramyldipeptide adjuvant (PEP), procine luteinizing hormone (LH) conjugated to hSG (pLH-hSG) in CFA or ovine LH (oLH) in CFA. Equal doses of boosters were given in either PEP or incomplete Freund's adjuvant (IFA) at 16 and 18 wk of age. Two groups of boars were immunized with either hSG + CFA or hSG + PEP (adjuvant controls). Two groups …


Growth And Magnesium Uptake Of Tall Fescue Lines At High And Low Potassium Levels, J. H. Edwards, Jeffrey F. Pedersen Jan 1986

Growth And Magnesium Uptake Of Tall Fescue Lines At High And Low Potassium Levels, J. H. Edwards, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Five tall fescue (Festuca arundinacea Schreb.) clonal lines with diverse root and xylem diameters were grown in nutrient solutions with magnesium (Mg) concentrations of 42, 125 and 250 µm and potassium K concentrations of 133 and 333 µm. Leaf Mg concentrations increased with increasing Mg rates at both low and high K concentrations. The tall fescue line with the largest root and xylem diameters had low leaf Mg concentrations, indicating a possible increased Mg tetany potential when consumed by cattle. The response of the K/(Mg+Ca) ratio in the plant, an indicator of tetany potential, to varying solution Mg at low …


Corn And Soybean Yield Response To Crop Residue Management Under No-Tillage Production Systems, Wallace Wilhelm, J. W. Doran, James F. Power Jan 1986

Corn And Soybean Yield Response To Crop Residue Management Under No-Tillage Production Systems, Wallace Wilhelm, J. W. Doran, James F. Power

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Crop residues (stover) have many potential uses by society: food, feed, shelter, fuel, and soil amendment. Use of residues for purposes other than as a soil amendment may have serious negative consequences on crop productivity. This study was conducted to investigate the yield response of continuous corn (Zea mays L.) and continuous soybean [Glycine max (L.) Merr.] to removal or addition of crop residues under no-tillage management. The study was conducted near Lincoln, NE, on a Crete-Butler silty clay loam (fine, montmorillonitic, mesic Pachic Arguistoll-Abruptic Argiaquoll) with 1 to 2% slope. Crop residue was collected and weighed immediately …


Carbon Dioxide Exchange Rate Of Tall Fescue-Leaf Area Vs. Leaf Weight Basis, Wallace Wilhelm, C. J. Nelson Sep 1985

Carbon Dioxide Exchange Rate Of Tall Fescue-Leaf Area Vs. Leaf Weight Basis, Wallace Wilhelm, C. J. Nelson

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The basis used for expression of carbon dioxide exchange rate (CER) of single leaves may alter the relative ranking of genotypes being selected for a breeding program. Therefore, field and growth chamber experiments were conducted on 16 genotypes of tall fescue (Festuca arundinacea Schreb.) to determine the relative merit of expressing CER data on a leaf area or leaf weight basis. Genotypes were grown in plots in the field and in pots in the growth chamber. The CER was measured using an infrared gas analyzer. Herbage yield was determined. Significant genotypic variation within experiments was found for CER when …


Tillage And Low-Pressure Center-Pivot Irrigation Effects On Corn Yield, Wallace Wilhelm, L.N. Mielke, J. R. Gilley Mar 1985

Tillage And Low-Pressure Center-Pivot Irrigation Effects On Corn Yield, Wallace Wilhelm, L.N. Mielke, J. R. Gilley

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Low-pressure sprinkler irrigation systems have the potential to save energy, but also may aggravate soil- and water-management problems. The objective of this research was to determine the influence of center-pivot sprinkler irrigation method in combination with various tillage practices on corn (Zea mays L.) yield and yield components. A center-pivot irrigation machine was designed to apply water by high-pressure-impact (HPI), low-pressure-impact (LPI), and low-pressure-spray (LPS) nozzles. Nozzles were sized and spaced to apply three different amounts of water: 100% (full irrigation), 75 and 50%. Three tillage treatments were used-till-plant (T), disk (D), and till-plant with chisel after last cultivation …


Intsormil 1985 Annual Report: Fighting Hunger With Research, John M. Yohe Jan 1985

Intsormil 1985 Annual Report: Fighting Hunger With Research, John M. Yohe

INTSORMIL Impacts and Bulletins

This annual report covers the activities for program Year 6, the final year of operation under the initial grant document.

The CRSP's present a unique model for conducting agricultural research in collaboration with developing country agricultural research programs.

The INTSORMIL program also demonstrates these characteristics:

-- INTSORMIL has the dual goal of improving agriculture in the developing countries and in the United States.

- The seven participating U.S. institutions agree to contribute at least 25% of the cost of the CRSP from non-federal resources (in money or in kind), justified on the basis of benefits that can accrue to their …


Cryogenic Preservation Of Semen From The Greater Sandhill Crane, George F. Gee, Murray R. Bakst, Thomas J. Sexton Jan 1985

Cryogenic Preservation Of Semen From The Greater Sandhill Crane, George F. Gee, Murray R. Bakst, Thomas J. Sexton

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Frozen gene pools (semen or embryos) can provide a safe place for the storage of genetic material for many generations. Cranes (Grus spp.) are one of many species in need of gene pool protection. Of the seven species and four subspecies considered rare or endangered (Archibald et al. 1981), two, the whooping crane (G. americana) and the Mississippi sandhill crane (G. canadensis pulla), are part of captive propagation projects at the Patuxent Wildlife Research Center in Laurel, Maryland. Greater sandhill crane (G. c. tabida) semen cryopreservation, under study at Patuxent since 1976 (Sexton …


Twenty-Four-Hour Profiles Of Prolactin And Testosterone In Ram Lambs Exposed To Skeleton Photoperiods Consisting Of Various Light Pulses, B. D. Schanbacher, W. Wu, J. A. Nienaber, G. L. Hahn Jan 1985

Twenty-Four-Hour Profiles Of Prolactin And Testosterone In Ram Lambs Exposed To Skeleton Photoperiods Consisting Of Various Light Pulses, B. D. Schanbacher, W. Wu, J. A. Nienaber, G. L. Hahn

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Individual groups of 6 ram lambs were housed within a controlled environment and exposed to one of 6 photoperiod schedules. Groups I and II received 8 (short day) or 16 (long day) h of continuous light, respectively; Groups III, IV and V were exposed to asymmetrical skeleton photoperiods consisting of a main light period of 7 h followed 9 h later by a light pulse of 1 h, 15 min or 1 min duration, respectively, and Group VI was exposed to a symmetrical skeleton photoperiod consisting of two 1-h light pulses positioned 16 h apart. After 4 weeks of treatment …


Soil Physical Characteristics Of Reduced Tillage In A Wheat-Fallow System, L. N. Mielke, Wallace Wilhelm, K. A. Richards, C.R. Fenster Dec 1984

Soil Physical Characteristics Of Reduced Tillage In A Wheat-Fallow System, L. N. Mielke, Wallace Wilhelm, K. A. Richards, C.R. Fenster

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Soil physical characteristics of reduced tillage for fallow-wheat (Triticum aestivum L.) were compared for two soils in western Nebraska. The soil physical environment influences the amount of water that enters soil, the availability of water for plants, and the microenvironment important to soil biological processes. Fallow tillage (plow, subtill, no till) did not affect bulk density in Alliance silt loam (fine silty, mixed mesic, Aridic Argiustolls). For Duroc loam (fine silty, mixed mesic Pachic Haplustolls), in which native sod was compared to the above three wheat-fallow tillage methods, numerous effects on soil physical properties were found. Reduced tillage reduced …


Crop Residue Removal And Soil Productivity With No-Till Corn, Sorghum, And Soybean, J. W. Doran, Wallace Wilhelm, J. F. Power Nov 1984

Crop Residue Removal And Soil Productivity With No-Till Corn, Sorghum, And Soybean, J. W. Doran, Wallace Wilhelm, J. F. Power

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Crop residues have been considered during the past decade as alternate energy sources to supplement dwindling fossil fuel sources and enhance energy independence in the United States. Agricultural scientists have demonstrated the importance of crop residues in reducing soil erosion, enhancing the soil physical environment for plant growth, and as a reserve for major crop nutrients. In eastern Nebraska, we evaluated the effects of various amounts of surface crop residues (aboveground dry matter remaining after harvest) on dryland production of no-till corn (Zea mays L.), sorghum [Sorghum bicolor (L.) Moench], and soybean [Glycine max (L.) Merrill] over …


Fighting Hunger With Research, Judy F. Winn Jul 1984

Fighting Hunger With Research, Judy F. Winn

INTSORMIL Impacts and Bulletins

The Sorghum/Millet Collaborative Research Program, INTSORMIL, combines the resources and research talent of host country research institutions, eight land grant universities, and the Agency for International Development. Its objective is to improve world-wide sorghum and millet production and utilization. This 5-year report shows that the international sorghum-millet research program is one in which researchers from the U.S. and host countries can effectively collaborate. The INTSORMIL External Evaluation Panel and other reviewers have and will continue to recommend program strengthening changes. Adjustments in research program content and scientist involvement will result as plans are made for future research.

Sorghum and millet …


Proceedings Of The 11th Annual Meeting, Southern Soybean Disease Workers (March 27-29, 1984, Ft. Walton Beach, Florida): Economics Of Soybean Disease, H. Jack Walters, Richard E. Stuckey, Edwin F. Koldenhoven, Murray E. Nance, James D. Arnett Mar 1984

Proceedings Of The 11th Annual Meeting, Southern Soybean Disease Workers (March 27-29, 1984, Ft. Walton Beach, Florida): Economics Of Soybean Disease, H. Jack Walters, Richard E. Stuckey, Edwin F. Koldenhoven, Murray E. Nance, James D. Arnett

Southern Soybean Disease Workers: Conference Proceedings

Contents

1984 Southern Soybean Disease Workers Officers

1984 Southern Soybean Disease Workers Program Committee

1984 Southern Soybean Disease Workers Committee Chairmen

Workshop

Diagnosing early season soybean disorders. D Stuckey and A Wrather

General session

Presidential address. HJ Walters

Southern United States Soybean Disease Loss Estimate for 1983. Southern Soybean Disease Workers, Soybean Disease Loss Estimate Committee. RP Mulrooney

Soybean nematodes. R Dunn presiding

A New Publication on the Soybean Cyst Nematode. WF Moore

Soybean Cultivars and Development of Populations of Meloidogyne incognita in Soil: A Concept of Tolerance. R Rodríguez-Kábana and DB Weaver

A Comparison of Soybean Cultivars for …


Growth Analysis Based On Degree Days, M. P. Russelle, Wallace Wilhelm, R. A. Olson, James F. Power Jan 1984

Growth Analysis Based On Degree Days, M. P. Russelle, Wallace Wilhelm, R. A. Olson, James F. Power

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Comparisons of growth analysis functions within and among experiments are often confounded by sources of variation other than those imposed by treatment. we suggest use of a temperature index, such as modified growing degree days, as the divisor in growth functions to facilitate treatment comparisons within certain experiments and to reduce the effects of differing temperature regimes among experiments on these comparisons. Three experiments were identified to provide data to analyze this new approach. Mean absolute growth rate (GR) and mean relative growth rate (RGR) were compared in two experiments with maize (Zea mays L.) conducted in eastern Nebraska. …


Endocrine Mechanisms Of Puberty In Heifers: Estradiol Negative Feedback Regulation Of Luteinizing Hormone Secretion, M. L. Day, K. Imakawa, M. Garcia-Winder, D. D. Zalesky, B. D. Schanbacher, Roger J. Kittok, J. E. Kinder Jan 1984

Endocrine Mechanisms Of Puberty In Heifers: Estradiol Negative Feedback Regulation Of Luteinizing Hormone Secretion, M. L. Day, K. Imakawa, M. Garcia-Winder, D. D. Zalesky, B. D. Schanbacher, Roger J. Kittok, J. E. Kinder

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The hypothesis that luteinizing hormone (LH) secretion in prepubertal females is responsive to estradiol negative feedback and that decreased feedback occurs as puberty approaches was tested in heifers. In the first experiment, seven heifers were maintained prepubertal by dietary energy restriction until 508 days of age (Day 0). All heifers were placed on a high-energy diet on Day 0 at which time they received no additional treatment (CONT), were ovariectomized (OVX) or were ovariectomized and subcutaneously implanted with estradiol-17β (OVX-E2). This feeding regimen was used to synchronize reproductive state in all heifers. A second experiment was performed with …


In Vitro Testosterone Secretion By Testicular Tissue From Young Bulls And The Effects Of Chronic And Acute Exposure To Estradiol- 17Β, M. J. D'Occhio, B. D. Schanbacher, J. E. Kinder Jan 1984

In Vitro Testosterone Secretion By Testicular Tissue From Young Bulls And The Effects Of Chronic And Acute Exposure To Estradiol- 17Β, M. J. D'Occhio, B. D. Schanbacher, J. E. Kinder

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The possibility that estradiol-17/3 may directly influence testicular steroidogenesis in bulls was investigated in vitro. Testicular tissues were incubated for 4 h and regression coefficients (b, ng·ml-1·h-1) based on the increase in testosterone in the medium were used to describe testosterone secretion rates. In the first experiment, testicular tissues from control bulls and bulls chronically implanted with estradiol were incubated in the absence (basal conditions) or presence of 10 mlU/ml human chorionic gonadotropin (hCG). Under basal conditions, testosterone secretion rates were similar for tissues from control (b = 24.1 ± 6.0) and implanted (b = 34.7 …


Effects Of Castration And Electrical Stimulation On Beef Carcass Quality And Palatability Characteristics, S. Kalstrup, H. R. Cross, B. D. Schanbacher, R. W. Mandigo Jan 1984

Effects Of Castration And Electrical Stimulation On Beef Carcass Quality And Palatability Characteristics, S. Kalstrup, H. R. Cross, B. D. Schanbacher, R. W. Mandigo

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Thirty bull and 30 heifer Hereford x Simmental calves were weaned at approximately 5 mo of age and assigned randomly to one of the following treatments: intact, conventionally castrated or luteinizing hormone-releasing hormone-immunized (LHRH). All animals were slaughtered at 16 mo of age and the right side of each carcass was electrically stimulated (ES) or restimulated (RES). Yield and quality grades were determined on both right and left sides after 24 h chilling. Longissimus muscles (LD) were obtained at 7 d postmortem for objective color measurements, chemical analysis, shear force and trained sensory panel evaluation. Semitendinosus muscles (ST) were also …


Notes: Differences Among Nematode Populations In Tall Fescue Pastures In North, Central, And South Alabama, Jeffrey F. Pedersen, R. Rodriguez-Kabana Jan 1984

Notes: Differences Among Nematode Populations In Tall Fescue Pastures In North, Central, And South Alabama, Jeffrey F. Pedersen, R. Rodriguez-Kabana

Department of Agronomy and Horticulture: Faculty Publications

Surveys of nematode populations in tall fescue (Festuca arundinacea Schreb.) pastures in north, central, and south Alabama in 1982 and 1983 showed significant differences in frequency of occurrence of many nematode species by geographical region. Although nematode damage has been implicated in the poor adaptation of tall fescue to the sandy soils of the extreme Southeast, many plant parasitic nematode species occurred in low frequency in south Alabama pastures. There were significant differences in the frequency of occurrence of Paratrichodorus christiei (Allen) Siddiqi by region. This nematode occurred with relatively high frequency in south Alabama in both years. There were …


Effects Of Water Flow Restriction And Environmental Factors On Performance Of Nursery-Age Pigs, John A. Neinaber, G. Leroy Hahn Jan 1984

Effects Of Water Flow Restriction And Environmental Factors On Performance Of Nursery-Age Pigs, John A. Neinaber, G. Leroy Hahn

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A series of three feeding trials was conducted to determine if nipple waterer flow rate affects the performance of nursery-age pigs and if there are any interaction effects with environmental factors. In the first trial, 42 barrows, 10 wk of age, were fed during a period of 4 wk at 5 or 35 C and given water ad libitum with flow rates of 100, 600 and 1,100 ml/min and a control treatment of 20 C and 600 ml/min.


Manipulation Of Endogenous And Exogenous Hormones For Red Meat Production, Bruce D. Schanbacher Jan 1984

Manipulation Of Endogenous And Exogenous Hormones For Red Meat Production, Bruce D. Schanbacher

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Growth and development of domestic livestock for red meat production are often discussed in the context of environmental factors, nutritional requirements, genetic potential and the anabolic agents affecting production efficiency. In this minireview, the effects of endogenous and exogenous hormones on animal growth are reviewed. The pituitary, pancreatic and gonadal hormones known to affect growth and(or) carcass composition are cited to illustrate and place into perspective the important contributions that the endocrine system makes to animal production. Manipulation of endogenous hormones through 1) administration of synthetic releasing and inhibiting peptides and 2) immunoneutralization techniques, will likely provide the livestock producer …


Pituitary-Testicular Responses Of Estradiol-17Β-Implanted Bull Calves To Continuous Versus Pulsatile Infusion Of Luteinizing Hormone Releasing Hormone, Bruce D. Schanbacher Jan 1984

Pituitary-Testicular Responses Of Estradiol-17Β-Implanted Bull Calves To Continuous Versus Pulsatile Infusion Of Luteinizing Hormone Releasing Hormone, Bruce D. Schanbacher

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The luteinizing hormone (LH), folliclestimulating hormone (FSH) and testosterone response of bull calves implanted with estradiol-17β to continuous and pulsatile infusion of luteinizing hormone releasing hormone (LHRH) has been examined. Estradiol-17β reduced serum LH and FSH concentrations and suppressed testosterone secretion and testicular growth when compared with sham-implanted bulls. Putsatile iv infusion of LHRH [500 ng every 2 h (6 μg/d)] for a 4-wk period to estradiol-17β- implanted bulls resulted in elevated mean serum LH and testosterone concentrations that were characterized by discrete secretory episodes. Mean serum FSH was also increased by LHRH pulse infusion, but LHRH-coup!ed secretory episodes were …


Hypothalamic Control Of The Post-Castration Rise In Serum Lh Concentration In Rams, B. D. Schanbacher, M. J. D'Occhio Jan 1984

Hypothalamic Control Of The Post-Castration Rise In Serum Lh Concentration In Rams, B. D. Schanbacher, M. J. D'Occhio

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Sexually mature rams were left intact, castrated (wethers), castrated and implanted with testosterone, or castrated, implanted with testosterone and pulse-infused every hour with LHRH. Serum concentrations of LH increased rapidly during the first week after castration and at 14 days had reached values of 13·1 ± 2·2ng/ml (mean ± s.e.m.) and were characterized by a rhythmic, pulsatile pattern of secretion (1·6 ± 0·1pulses/h). Testosterone prevented the post-castration rise in serum LH in wethers (1·0 ± 0·5ng/ml; 0 pulses/h), but a castrate-type secretory pattern of LH was obtained when LHRH and testosterone were administered concurrently (10·7 ± 0·8 ng/ml; 1·0 pulse/h). …


Thermal Shrinkage Temperature Of Intramuscular Collagen Of Bulls And Steers, M. D. Judge, E. D. Aberle, H. R. Cross, B. D. Schanbacher Jan 1984

Thermal Shrinkage Temperature Of Intramuscular Collagen Of Bulls And Steers, M. D. Judge, E. D. Aberle, H. R. Cross, B. D. Schanbacher

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The thermal shrinkage temperature (Ts) of bull muscle collagen was higher (Ps from bull muscles increased from 12 to 15 mo and decreased from 15 to 18 mo of age, whereas that of steer muscles did not change with age (age × sex interaction, Ps. Carcass electrical stimulation did not affect collagen Ts in steer muscle, but there was a trend toward reduction of Ts in collagen of bull muscle.


Root System Characteristics Of Two Soybean Isolines Undergoing Water Stress Condition, A. F. Garay, Wallace Wilhelm Nov 1983

Root System Characteristics Of Two Soybean Isolines Undergoing Water Stress Condition, A. F. Garay, Wallace Wilhelm

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Environmental stress may have a differential influence on root development of soybean [Glycine max (L.) Merr.] isolines which vary in pubescence density. Root length density and root dry matter distribution as a function of depth and distance from the row were determined for two isolines of 'Harosoy' soybean in association with an experiment designed to evaluate the influence of epidermal pubescence on root development, water use, and photosynthetic characteristics of the two isolines. The isolines, Harosoy normal (HN) and Harosoy dense (HD), differed in the density of trichomes on the epidermal surfaces of leaves, stems, and pods. The study …


Root System Characteristics Of Two Soybean Isolines Undergoing Water Stress Conditions, A. F. Garay, Wallace Wilhelm Nov 1983

Root System Characteristics Of Two Soybean Isolines Undergoing Water Stress Conditions, A. F. Garay, Wallace Wilhelm

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Environmental stress may have a differential influence on root development of soybean [Glycine max (L.) Merr.] isolines which vary in pubescence density. Root length density and root dry matter distribution as a function of depth and distance from the row were s determined for two isolines of 'Harosoy' soybean in association with an experiment designed to evaluate the influence of epidermal pubescence on root development, water use, and photosynthetic characteristics of the two isolines. The isolines, Harosoy normal (HN) and Harosoy dense (HD), differed in the density of trichomes on the epidermal surfaces of leaves, stems, and pods. The …


Proceedings Of The 10th Annual Meeting, Southern Soybean Disease Workers (March 15-17, 1983, Houston, Texas): Significance Of Soybean Diseases, Wayne Winner, H. Jack Walters, Dick Stuckey, Jerry Berggren, J. Dan Smith Mar 1983

Proceedings Of The 10th Annual Meeting, Southern Soybean Disease Workers (March 15-17, 1983, Houston, Texas): Significance Of Soybean Diseases, Wayne Winner, H. Jack Walters, Dick Stuckey, Jerry Berggren, J. Dan Smith

Southern Soybean Disease Workers: Conference Proceedings

Contents

1983 Southern Soybean Disease Workers Officers

1983 Southern Soybean Disease Workers Program Committee

Committee Chairmen

General session

Presidentiial address. W Winner

Soybean Research Needs and the American Soybean Association. KJ Smith

American Soybean Association Pesticide Assessment in the Administrative Hearing: An Educational Guide for the Agricultural Scientist. MT Olexa and AH Daniels

Soybean Disease Loss Estimate. E Koldenhoven

The influence of cultural practices on disease incidence. JG Kantzes presiding

The Relationship Between Chloride Uptake and Leaf Scorch of Soybeans. MB Parker, TP Gaines, and GJ Gascho

Effect of No-tillage on Fusarium Blight of Soybean on Delmarva. B Carroll

Effect …