Agricultural Science Commons^™

Impact Of Egg Storage On Embryo Development, M. R. Bakst, V. Akuffo

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

1. New information is introduced and other information reviewed regarding the impact of egg storage on the integrity of the avian embryo.

2. Morphologically, the blastoderm from an egg which has been stored more than 10 days is often asymmetrical and may have an attenuated appearance.

3. Fresh egg breakouts coupled with the perivitelline layer sperm-hole determination procedure provide detailed information on the male's contribution to overall fertility.

4. The biological basis for embryonic mortality in eggs stored for longer than 10 days remains the subject of speculation.

Recycled Paper Products As Substitutes For Gelling Agent In Screwworm (Diptera: Calliphoridae) Larval Diet, M. F. Chaudhury, L. Alfredo Alvarez, L. Lopez Velazquez

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

Absorbent recycled paper products were tested and compared with a sodium polyacrylate gelling agent, Aquatain, for solidifying larval diets of the screwworm, Cochliomyia hominivorax (Coquerel). A recycled newsprint product, Terra-Mulch, when mixed with water and dietary ingredients produced a diet medium of homogeneous texture that supported larval growth and development comparable to the standard diet prepared with the gelling agent. Biological yields as calculated from number of pupae per tray from both the diets were similar. Three other types of recycled paper products were tested. Although less homogeneous in texture, these diets were as good as the diet with Terra-Mulch. …

Biomass And Nitrogen Traits Of Summer Pigeon Peas And Winter Wheat Grown For Three Rotations In Containers, Srinivas C. Rao, Charles T. Mackown, James E. Bidlack

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

Pigeon pea [Cajanus cajan (L.) Millsp.] cultivars, ‘Georgia-1’ and ‘ICPL-87’, were grown without inoculation and with Bradyrhizobium inoculation (multistrain, TAL 1127, or TAL 1132) to evaluate legume dry weight (DW) and nitrogen (N) content, soil mineral N, and subsequent wheat (Triticum aestivum L.) productivity. Pigeon peas were grown during summer and ‘TAM 101’ wheat was grown during winter, along with summer fallow controls fertilized with 0, 45, and 90 kg N ha^-1, in 36-cm diam. 20-L pots from 1992 to 1995. Representative pigeon peas were harvested in the fall and remaining plants were incorporated into the …

Growing Rice Grain With Controlled Cadmium Concentrations, Urszula Kukier, Rufus L. Chaney

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

Two solution studies were conducted a) to investigate the uptake of zinc (Zn) and cadmium (Cd) by rice plants (Oryza sativa L.) and interaction between these elements, and b) to determine experimental conditions for growing rice grain with desired Cd concentration for an animal feeding study. In both studies, free metal activities of cadmium and cationic microelements were buffered by an excess of chelating agents. The first study was a factorial design with two Zn levels (1.0 and 3.89 μM) and four Cd levels (0.81, 1.44, 2.56 and 4.55 μM) in the solution. In the second study, rice was …

Kura Clover And Birdsfoot Trefoil Response To Soil Ph, L. R. Dehaan, M. P. Russelle, C. C. Sheaffer, N. J. Ehlke

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

Use of the rhizomatous perennial forage legume kura clover (Trifolium ambiguum M. Bieb.) has been limited by slow establishment. Mature kura clover responds to liming on some acid soils, but the soil pH required for vigorous growth of young plants is unknown. A factorial greenhouse experiment was conducted with two kura clover cultivars (Rhizo and Endura) and one cultivar of birdsfoot trefoil (Lotus corniculatus L., Norcen) planted in three soil types (Sartell loamy fine sand, Hubbard loamy sand, and Sanborg clay loam) amended with Ca(OH)₂ to obtain six soil pH levels. The experiment was performed twice, once …

Quantifying Laboratory And Field Variability To Assess Potential For Carbon Sequestration, R. A. Bowman, J. D. Reeder, B. J. Wienhold

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

Accurate measurements of soil organic carbon (SOC) levels are essential to assess changes in C sequestration rates. To this end we conducted studies to evaluate laboratory variability in SOC concentration measured at USDA-ARS laboratories in Akron, CO, Cheyenne,WY, and Lincoln, NE. At the Akron laboratory we also evaluated field spatial variability within common cropping treatments in order to assess the potential to quantify significant changes in SOC content associated with rotations of varying cropping intensities. Our data showed very low coefficients of variation for SOC values from each of the three laboratories, and the same average SOC values for soils …

Use Of Nonsettable Eggs To Evaluate Turkey Hen Fertility, M. R. Bakst, S. Mcgary, I. Estevez, T. Knapp

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

The use of nonsettable eggs (checked, cracked) to perform fresh egg breakouts to estimate true fertility and to assess the rate of sperm penetration of the perivitelline layer overlying the germinal disc was evaluated. Germinal discs and the perivitelline layer overlying the germinal disc were accessible for assessments. The stage of blastodermal development positively correlated (r = 0.65, P < 0.0001) with eggshell thickness. It was also determined that the perivitelline layer of nonsettable eggs could be isolated and stained to determine the presence or absence of sperm holes. True fertility of nonsettable eggs (checked and cracked only) and settable eggs was 90 and 95%, respectively. It was concluded that checked and cracked eggs could be used to estimate the true fertility of a flock.

Phenotypic Traits As Reliable Indicators Of Fertility In Male Broiler Breeders, S. Mcgary, I. Estevez, M. R. Bakst, D. L. Pollock

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

Genetic selection procedures applied to improve broiler performance may negatively impact the subsequent reproductive efficiency of breeders, particularly in males. Identification of traits that reliably indicate individual male fertility would facilitate selection for reproduction. We hypothesized that physical traits, such as comb area, relative testicular weight, and testicular weight asymmetry, may correlate with fertility in two male-selected primary broiler breeder strains (A and B). Thirty males per strain, individually housed with an average of 10 females, were evaluated at five age periods within the 30-to-50-wk breeding cycle. Flock fertility by candling eggs at Day 19 of incubation and sample fertility …

Mutual Interference Of Pheromone Traps Within Trap Lines On Captures Of Boll Weevils (Coleoptera: Curculionidae), Thomas W. Sappington

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

Traps baited with the synthetic aggregation pheromone of the boll weevil (Anthonomus grandis Boheman) are often used to monitor population fluctuations, distribution, and behavior. However, many factors generate variability in daily captures, making interpretation of trapping data difficult. Previous studies have shown that wind speed in the microenvironment around a trap can greatly affect numbers captured on a given day. It is possible that variation in air movement may also generate variation in trap captures through its effects on the pheromone plume. The current study was conducted to determine whether five traps placed in a line at two commonly …

Nitrogen Fertilization Of Irrigated Corn In A High Residual Soil N Environment In The Arkansas River V Alley, Ardell D. Halvorson, Frank Schweissing, Curtis Reule

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

High levels of residual soil NO₃-N are present in the soils in the Arkansas River Valley where melons and other vegetable crops are produced. The amount of N fertilizer required to optimize the yield potential of crops, such as corn, following vegetables needs to evaluated to reduce NO₃-N leaching potential in the Valley where high NO₃-N levels have been reported in the ground water. This study evaluated the effects of N fertilizer rate (0, 50, 100, 150, 200, and 250 lb N/a) and N source (urea and Polyon®³) on corn yields following …

One Plus One Equals Three: The Synergistic Effects Of Crop Rotation On Soil Fertility And Plant Nutrition, Walter E. Riedell, Joseph L. Pikul Jr., Lynne Carpenter-Boggs

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

Corn grown under annual corn-soybean crop rotation has greater accumulation of certain mineral nutrients and higher yields than corn grown in monoculture. This study was conducted to determine if complex crop rotations (with legumes in the rotation as alfalfa hay as well as soybean row crops) and different levels of agriculture chemical input affect soil fertility and corn mineral nutrient composition. The effects of crop rotation [monoculture corn, corn-soybean 2-yr rotation, corn-soybean- wheat underseeded with alfalfa-alfalfa 4-yr rotation] and input level [high input (fertilizer application for 8.15 Mg ha^-1 yield goal, prophylactic herbicide and insecticide application, fall moldboard plow/spring …

Mineralization Of N In Swine Manure Amended Soils As A Function Of Soil Temperature, Moisture, And Texture, Brian J. Wienhold, Bahman Eghball

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

Manure can serve as an effective fertilizer source if used properly or can lead to environmental contamination if used improperly. Proper use of manure requires some know ledge of the availability of nutrients contained in the manure. To better understand how soil and environmental variables effect N mineralization in manure amended soils a laboratory study was conducted to measure N-mineralization rates as a function of soil texture, water regime, and temperature. This study is part of a national effort to develop a model to predict nutrient availability from various manure sources across a range of soil and environmental conditions. There …

A Personal Account Of Creating The Sterile Insect Technique To Eradicate The Screwworm From Curacao, Florida And The Southeastern United States, Alfred H. Baumhover

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

The history is recounted of developing the sterile insect technique to eradicate the screwworm, Cochliomyia hominivorax (Coquerel), from the Caribbean island of Curacao, Florida and the southeastern U.S. Observations of screwworm biology and challenges faced in conducting these eradication projects are described by the author who worked on all aspects of the research and field operations. Eradication was first demonstrated on Curacao, essentially a 170 mi² outdoor laboratory. The population dynamics of the wild screwworm was determined and overflooding ratios and dispersal patterns essential for population suppression were defined. Eradication was achieved with minimal resources by attacking the pest …

Threat Of Foreign Arthropod-Borne Pathogens To Livestock In The United States, Ralph A. Bram, John E. George, Robert E. Reichard, Walter J. Tabachnick

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

There are many exotic animal pathogens throughout the world that, if introduced into the United States, could have a significant detrimental impact on the health of livestock, agricultural economy, the environment, and public health. Many of these pathogens are arthropod-borne and potential vectors are readily available in the United States. A number of these arthropod-borne pathogens are discussed here as examples that illustrate the potential risk and the consequences of inadvertent introductions. Several International agencies have a role in global surveillance and in controlling animal diseases should they begin to expand their range. The risk to the United States is …

Soil- And Plant-Water Dynamics In A C3/C4 Grassland Exposed To A Subambient To Superambient Co2 Gradient, H. Wayne Polley, Hyrum B. Johnson, Justin D. Derner

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

Plants may be more sensitive to carbon dioxide (CO₂) enrichment at subambient concentrations than at superambient concentrations, but field tests are lacking. We measured soil-water content and determined xylem pressure potentials and δ¹³C values of leaves of abundant species in a C3/C4 grassland exposed during 1997-1999 to a continuous gradient in atmospheric CO₂ spanning superambient concentrations (200-560 µmol mol^-1).

Arsenic(Iii) Oxidation And Arsenic(V) Adsorption Reactions On Synthetic Birnessite, Bruce A. Manning, Scott E. Fendorf, Benjamin Bostick, Donald L. Suarez

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

The oxidation of arsenite (As(III)) by manganese oxide is an important reaction in both the natural cycling of As and the development of remediation technology for lowering the concentration of dissolved As(III) in drinking water. This study used both a conventional stirred reaction apparatus and extended X-ray absorption fine structure (EXAFS) spectroscopy to investigate the reactions of As(III) and As(V) with synthetic birnessite (MnO₂). Stirred reactor experiments indicate that As(III) is oxidized by MnO₂ followed by the adsorption of the As(V) reaction product on the MnO₂ solid phase. The As(V)-Mn interatomic distance determined by EXAFS analysis …

Differences Among Mycorrhizal Fungi For Mineral Uptake Per Root Length Of Switchgrass Grown In Acidic Soil, R. B. Clark

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

Plants commonly encounter deficient and=or toxic levels of mineral elements when grown in acidic soil, and arbuscular mycorrhizal fungi (AMF) have potential to overcome many of these effects. Switchgrass (Panicum virgatum L.) was grown in acidic Lily soil (Typic Hapludult) at pH_Ca 4 and 5 (soil : 10mM CaCl₂, 1 : 1) and inoculated with Glomus (G.) clarum, G. diaphanum, G. etunicatum, G. intraradices, Gigaspora (Gi.) albida, Gi. margarita, Gi. rosea, and Acaulospora (A.) morrowiae to determine differences among mycorrhizal (AM) plants for mineral uptake per root length (RL). Shoots of AM plants grown …

Segregation Of Spermatozoa Within Sperm Storage Tubules Of Fowl And Turkey Hens, L. M. King, J. P. Brillard, M. R. Bakst, A. M. Donoghue

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

In avian species, spermatozoa reside in the oviduct for prolonged periods in specialized structures known as sperm storage tubules, but little is known about the relative distribution of spermatozoa in these tubules after successive inseminations by different males. The staining efficacies of various fluorescent dyes for fowl and turkey spermatozoa were evaluated to investigate one proposed mechanism of sperm competition. Hens were then inseminated at different intervals with stained and unstained spermatozoa to observe the spatial distribution of spermatozoa within the storage tubules. Several novel fluorescent lipophilic tracers that successfully stain mammalian spermatozoa either did not stain fowl or turkey …

Genetic Analysis Of Feed Quality And Seed Weight Of Sorghum Inbred Lines And Hybrids Using Analytical Methods And Nirs, C. Hicks, M. R. Tuinstra, Jeffrey F. Pedersen, F. E. Dowell, K. D. Kofoid

Department of Agronomy and Horticulture: Faculty Publications

Eight lines of grain sorghum and their F1 hybrids were evaluated for contents of crude protein (CP), fat (FAT), and starch (STA); protein digestibility (PD); and in vitro dry matter disappearance (IVDMD). The effect of seed weight (SW) on these traits and the potential use of near infrared reflectance spectroscopy (NIRS) to predict them also were investigated. The male lines included three normal-seeded lines (TX2737, TX435, and P954063) and two largeseeded lines (PL-1 and Eastin1). The female lines included commonU.S. seed parent lines (Wheatland, Redlan, and SA3042). The lines and their hybrids were grown under dryland conditions at Kansas State …

Combinatorial Control Of Yeast Fet4 Gene Expression By Iron, Zinc, And Oxygen, Brian M. Waters, David J. Eide

Department of Agronomy and Horticulture: Faculty Publications

Acquisition of metals such as iron, copper, and zinc by the yeast Saccharomyces cerevisiae is tightly regulated. High affinity uptake systems are induced under metal-limiting conditions to maintain an adequate supply of these essential nutrients. Low affinity uptake systems function when their substrates are in greater supply. The FET₄ gene encodes a low affinity iron and copper uptake transporter. FET₄ expression is regulated by several environmental factors. In this report, we describe the molecular mechanisms underlying this regulation. First, we found that FET₄ expression is induced in iron-limited cells by the Aft1 iron-responsive transcriptional activator. Second, FET …

Repellency Of Ir3535, Kbr3023, Para-Menthane-3,8-Diol, And Deet To Black Salt Marsh Mosquitoes (Diptera: Culicidae) In The Everglades National Park, Donald R. Barnard, Ulrich R. Bernier, Kenneth H. Posey, Rui-De Xue

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

IR3535, KBR3023, para-menthane-3,8-diol (PMD), and deet were evaluated in controlled studies with human subjects (n = 5) for repellency to black salt marsh mosquitoes (Ochlerotatus taeniorhynchus Wiedemann), in the Everglades National Park, FL. In tests of 6-h duration, with an average mosquito biting pressure on exposed forearm skin of 19.5 (±13.7) bites per minute, the mean percent repellencies (SE) for IR3535, KBR3023, PMD, and deet was 88.6 (3.2), 97.5 (1.7), 89.2 (2.9), and 94.8 (2.5), respectively. Mean complete protection times (SE) for IR3535, KBR3023, PMD, and deet were 3.0 (1.0), 5.4 (0.6), 3.8 (1.4), and 5.6 (0.5) h, …

Electrical Conductivity Monitoring Of Soil Condition And Available N With Animal Manure And A Cover Crop, R. A. Eigenberg, John W. Doran, John A. Nienaber, Richard B. Ferguson, B. L. Woodbury

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

Development of sustainable agricultural management systems will depend, in part, on the ability to better use renewable resources, such as animal manure, and to synchronize the levels of soil available N with crop plant needs during the growing season. This study was conducted at the US Meat Animal Research Center in the central USA to determine whether differences in electromagnetic (EM) soil conductivity and available N levels over a growing season can be linked to feedlot manure/compost application and use of a green winter cover crop. A series of soil conductivity maps of a research cornfield were generated using global …

Reductions In Grassland Species Evenness Increase Dicot Seedling Invasion And Spittle Bug Infestation, Brian J. Wilsey, H. Wayne Polley

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

Previous experiments that tested whether diverse plant communities have lower invasibility have all varied species richness. We experimentally varied evenness of four grassland species (three grasses and one forb) by planting a field experiment in Texas, and monitored the number of unplanted dicot and monocot species that invaded plots for two growing seasons. By varying evenness, we eliminated any sampling effect in our diversity treatment, because all plots contained the same plant species. Experimentally reducing evenness led to a greater number of dicot invaders, which emerged in plots throughout the growing season, but had less of an effect on monocot …

Oviducal Sperm Storage In Turkeys: Spatial Distribution Of Sperm Within The Uterovaginal Junction Sperm-Storage Tubules, M. R. Bakst, Bryan T. Vinyard

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

The spatial distribution of sperm within the sperm storage tubules (SST) found in
the uterovaginal junction (UVJ) of the turkey is not known. In this study, we inseminated sperm stained with a fluorescent dye (Hoechst 33342) to determine their distribution in SST in the ventral, dorsal, and lateral regions of the proximal, middle, and distal regions of the UVJ. There was no preferential filling in the ventral-dorsal axis of the UVJ. In contrast, preferential filling of the SST was observed in the middle section of the UVJ. Here the individual SST were clearly longer and more pleomorphic than the SST …

Physiology And Reproduction: Embryonic Development From First Cleavage Through Seventy-Two Hours Incubation In Two Strains Of Pekin Duck (Anas Platyrhynchos), V. Dupuy, B. Nersessian, M. R. Bakst

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

Embryonic mortality is a significant problem plaguing the commercial duck industry worldwide. Yet, an objective means to stage development of the duck embryo is lacking. Such a staging procedure, which is described in this study, is essential for the critical and reproducible assessment of embryo development. The morphological features associated with duck embryo development are very similar to those of the chicken, although the duck embryo develops more slowly. The staging scheme presented here provides objective morphological criteria describing the embryonic development of the duck.

Beet Armyworm (Lepidoptera: Noctuidae) Host Plant Preferences For Oviposition, S. M. Greenberg, T. W. Sappington, T.-X. Liu

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

Beet armyworm, Spodoptera exigua (Hübner), oviposition preferences were determined on five host plants: cabbage (Brassica oleracea capitata L.), cotton (Gossypium hirsutum L.), bell pepper (Capsicum annuum L.), pigweed (Amaranthus retroflexus L.), and sunflower (Helianthus annuus L.) in no-choice, two-choice, and five-choice tests. Tests were conducted in the laboratory, greenhouse, and field cages. Oviposition preferences were compared on the basis of two measurements, the proportion of eggs laid on the plants to total that were deposited, and the oviposition preference index defined as [(number of eggs laid on the plant) - (number of eggs laid on …

Soil Electrical Conductivity Classification: A Basis For Site-Specific Management In Semiarid Cropping Systems, Cinthia K. Johnson, David A. Mortensen, Brian J. Wienhold, John F. Shanahan, John W. Doran

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

Site specific management (SSM) has the potential to improve both economic and ecological outcomes in agriculture. Effective SSM requires strong and temporally consistent relationships between identified management zones, underlying soil physical, chemical and biological parameters defining yield potential, and crop yield. In a farm-scale (250 ha) experiment in semiarid northeastern Colorado, each of eight 31-ha fields was individually mapped for soil apparent electrical conductivity (EC_a) and classified into four management zones (ranges of EC_a). Soil analyses revealed a strong negative relationship between EC_a zones and soil parameters associated with innate fertility (P ≤ 0.06). …

Response Of Irrigated Corn To Nitrogen Fertility Level Within Two Tillage Systems, Ardell D. Halvorson, Walter Bausch, Harold Duke, Curtis Reule

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

Irrigated farmers generally utilize intensive tillage to manage crop residues and prepare a seedbed for com. Nitrogen fertilizer management practices have been developed for conventional-till (CT) irrigated com production. Little information is available for no-till (NT) and reduced-till (RT) irrigated com production systems. This paper compares the response of irrigated continuous com to N fertility level under CT and NT or RT production systems on a Fort Collins clay loam soil from 1999 through 2001. Grain yields increased similarly with increasing available N level [soil NO₃-N (0-3 ft) plus fertilizer N added] in 1999,2000, and 2001 for both …

Starter Fertilizer Effects On Soybean Grain Yield And Quality, S.L. Osborne, W.E Riedell, J.L. Pikul Jr

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

Fertilizing soybeans (Glycine max (L.) Merrill) is not an entirely new concept; for a number of years, scientists have investigated the effect of nitrogen (N) fertilizer on yield and quality of soybeans. The objective of this research was to investigate the effect of starter fertilizer N rates and sources on soybean yield, protein, and oil content in the cool soils of the Northern Great Plains. A field experiment was established within a two-year corn (Zea mays L.) soybean rotation. Using a split-plot design with four replications. Whole plots were no-till (NT) and conventional tillage (CT) and the split …

Impact Of Intensive Cropping Systems On Physical Properties Of Surface Soils, G.A. Peterson, D.G. Westfall, L.A. Sherrod, T. M. Shaver

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

The objective of this paper is to report the cumulative effects of cropping system intensification on the near surface soil physical properties (surface one inch of soil) within the Colorado dryland agroecoystem project, which has been in existence since 1986. Intensifying cropping systems from wheat-fallow to wheat-com-fallow to continuous cropping, increased crop residue return to the soil. Returning more residue to the soil surface: (I) decreased bulk density; (2) increased effective porosity; (3) increased sorptivity; (4) increased macro soil aggregation; and (5) appeared to improve potential water capture of the overall system. Increases in surface soil aggregation and effective porosity …