Life Sciences Commons^™

Beef Ribeye Muscle Glycogen And Color Response As Affected By Dietary Regimen And Postmortem Electrical Stimulation In Young Bulls, Mark R. Miller, H. Russell Cross, Marietta J. Buyck, John D. Crouse

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Utilization of the intact male by the beef industry has been the focus of much research in recent years. Advantages of bulls compared to steers in production efficiency, performance, and carcass leanness have been well documented. Disadvantages include aggressive behavior, darker postmortem muscle color, lower USDA quality grades, and, often, less tender meat. The superior production performance of bulls has not been utilized by the meat and livestock industries partly because of these disadvantages.

Postmortem muscle color is associated with energy content of the diet, antemortem muscle glycogen content, postmortem muscle pH decline, and ultimate pH, all of which are …

Factors Associated With Tenderness Of Three Beef Muscles, Mohammad Koohmaraie, Steven C. Seideman, John D. Crouse

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Tenderness is the prominent quality determinant and probably the most important sensory characteristic of beef steak and roast meat. Currently postmortem aging (storage of carcass at refrigerated temperatures for 8 to 14 days) appears to be the best method for producing tender meat. Although the improvement in meat tenderness as a result of postmortem aging is measurable both subjectively and objectively, the exact mechanism responsible for this improvement in tenderness is unknown.

It is well known that different muscles within the same carcass react differently to postmortem storage; for example, tenderloin is tender to begin with and does not improve …

Fetal Development In Cows With Multiple Fetuses, Sherrill E. Echternkamp

Roman L. Hruska U.S. Meat Animal Research Center: Reports

About 60% of the nutrient requirements for beef production in the U.S. are for maintenance of the breeding herd. In addition, the bovine female only produces about .7 of her body wt per yr in progeny wt. Thus, increasing the reproductive rate in beef cattle would have a major economic benefit. Although most bovine females are capable of gestating two calves, the natural frequency of twin births is low, ranging from less than .5% to 4% of the calvings, depending upon the breed of cattle. Several studies have indicated that the frequency of multiple births in cattle can be increased …

Growth And Carcass Traits Of Heifers As Affected By Hormonal Treatment, John D. Crouse, Bruce D. Schanbacher, H. Russell Cross, Steven C. Seideman, Stephen B. Smith

Roman L. Hruska U.S. Meat Animal Research Center: Reports

The beef industry traditionally has discriminated against young heifers in the marketplace when compared with steers. Price discrimination was probably the result of sex effects on fat partitioning and distribution. Also, steers have been observed to be more efficient than heifers in the conversion of feed to carcass weight.

Both testes and ovaries secrete steroids that influence performance traits of cattle. Testosterone appears to stimulate rate of gain and efficiency of feed conversion in the male. Efficiencies of conversion of feed to live animal weight gains have been less in spayed feedlot heifers than in intact heifers.

It has been …

Germ Plasm Evaluation In Cattle, Larry D. Cundiff, Robert M. Koch, Keith E. Gregory

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Breed differences in performance characteristics are an important genetic resource for improving efficiency of beef production. Diverse breeds are required to exploit heterosis and complementarity through crossbreeding and to match genetic potential with diverse market requirements and climatic zone-feed resource situations.. Genetic variation among breeds can be used to provide an array of beef products that differ widely in fat and caloric content. Diverse feed resources will continue to be used for cow herds among and within different geographical regions of the U.S. Thus, it is important to characterize breeds of cattle representing different biological types for a wide spectrum …

Germ Plasm Utilization In Beef Cattle, Keith E. Gregory, Larry V. Cundiff, Robert M. Koch

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Heterosis achieved through well-organized crossbreeding systems can be used to increase weight of calf weaned per cow exposed to breeding by about 20%. Comprehensive programs of breed characterization have revealed large differences among breeds for most biological traits of economic importance.

Ahigh percentage of beef cattle in the U.S.and globally are in herds too small to use well organized crossbreeding systems on a self-contained basis. Further, there is wide fluctuation in breed composition between generations in rotational crossbreeding systems. Thus, there is need for experimental evaluation of the potential of composite populations as an alternative, or, as a supplement to …

Investigation Of The Major Histocompatibility Complex In Cattle And Its Association With Economically Important Traits, Noelle E. Muggli, Michael J. Stear, Roger T. Stone

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Efficiency of animal production could be increased by reducing losses due to diseases. Therefore, disease resistance is an obvious trait to include in a selection program. However, how to incorporate this trait into the program is a difficult question. While it has been experimentally shown that selection for resistance against specific diseases is effective, it would be impossible to select for resistance to all potential diseases. Also, selection studies in mice show that increasing resistance to one disease can result in increased susceptibility to other diseases. This may be because antagonistic relationships exist among the mechanisms of the immune system. …

Mating And Grazing Behavior Of Low And High Serving Capacity Beef Bulls During Average And Heavy Mating Loads At Pasture, Garth W. Boyd, Donald D. Lunstra, Larry R. Corah

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Although artificial insemination is widely used in dairy cattle, it has found only limited application in beef cattle. Use of bulls in natural mating programs accounts for over 90% of the pregnancies achieved each year in the U.S. beef cattle industry, and a large percentage of the beef bulls used for natural mating are purchased as yearlings. Many of these yearling bulls undergo a breeding soundness examination prior to sale or the breeding season. This involves visual and manual examination of the genital system as well as assessment of semen, which is usually collected by electroejaculation. However, sex drive and …

Nutritional Value Of Anaerobically Fermented Beef Cattle Wastes As A Feed Ingredient For Livestock, Ronald L. Prior, Andrew G. Hashimoto, John D. Crouse

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Waste is produced in large quantities in cattle feedlots, and this is a potential environmental pollutant. Recycling of feedlot waste as livestock feed has been investigated extensively as one means of lowering the disposable waste load. Refeeding fresh manure will only partially alleviate waste disposal problems. In one study, only about one-half of the manure collected daily could be refed, and the remainder was discarded.

Currently, there is increased interest in the development of a microbial process for recycling and utilizing feedlot wastes. Commercial digestors are in operation. In some of these systems, the potential exists for capturing methane as …

Serum Concentrations Of Luteinizing Hormone, Testosterone, And Thyroid Hormones In Low And High Serving Capacity Beef Bulls, Garth W. Boyd, Donald D. Lunstra, Bruce D. Schanbacher, Larry R. Corah

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Adequate sex drive in bulls is essential for natural mating to be successful. Expression of male sexual behavior and mating ability during sexual maturation is dependent upon attaining adequate testicular development and blood levels of luteinizing hormone (LH) and testosterone (T). Several researchers have investigated the relationship between levels of sexual behavior in postpubertal bulls and blood concentrations of LH and T. Some of these researchers reported a positive relationship between T and serving capacity (SC), and others found that individual differences in sexual performance could not be predicted based on circulating levels of T or LH. In those studies, …

Relationship Of Growth Hormone, Prolactin, And Thyrotropin Secretion To Individual And Progeny Performance Of Hereford Bulls, Danny L. Ohlson, Robert M. Koch, John Klindt, Steven L. Davis

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Evidence from several studies has supported a predictive relationship between measures of somatotropic hormones and genetically determined growth potential in domestic ruminants. In these studies, blood concentrations of hormones associated with growth were generally higher in lines or breeds with greater growth potential. However, no significant positive correlations between measures of hormone secretion and measures of growth in individual animals were observed.

The present study further assesses the association between growth potential, growth rate, and secretion of growth hormone (GH), prolactin (PRL), and thyrotropin (TSH) using bulls of two Hereford lines that differ in growth rate as a result of …

Twinning And Efficiency Of Beef Production, Gordon E. Dickerson, Pedro Guerra-Martinez, Gary Anderson, Ronnie D. Green

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Twinning is relatively rare in most breeds of beef cattle - less than 1 to 2% of calvings and less frequent for immature females. Twin calving has generally been considered undesirable because of the smaller calf size, higher calf mortality, infertility of females born twin with a male, more retained placentas, and possible delayed rebreeding experienced with twin calvings when observed under feeding and management that is geared to single calving. However, costs for just maintaining the breeding herd account for over one-half of the total costs of beef production. Thus genetic twinning may offer a means of increasing total …

Roman L. Hruska U.S. Meat Animal Research Center: Overview, Robert R. Oltjen

Roman L. Hruska U.S. Meat Animal Research Center: Reports

The U.S. Meat Animal Research Center (U.S. Meat Animal Research Center) was authorized by Congress on June 16, 1964, thereby creating a single facility that provides an unusual opportunity for making major contributions to the solution of problems facing the U.S. livestock industry. Development of the 35,000-acre facility started in the spring of 1966and is continuing at the present time. Phase I construction, consisting of an office-laboratory building for intensive investigations, was completed in January 1971.These facilities provide a physical plant for 42 scientists and about 200 support personnel. Phase II construction, consisting of the Meats Research Laboratory and the …

Zinc And Protein Levels In Finishing Diets Of Medium-And Large-Frame Steers, Wilson G. Pond, Robert R. Oldjen

Roman L. Hruska U.S. Meat Animal Research Center: Reports

The National Research Council lists the daily protein requirements of medium-frame and large-frame steers weighing 770 lb and gaining 2.2 lb daily as 1.7 and 1.8 lb, respectively; comparable values at 1,100 lb are 1.9 and 2.1 lb. These amounts of protein are expected to be provided for medium-frame steers weighing 880 lb and gaining weight at 2.2 lb daily by a diet containing 10.3% protein; the corresponding value for large-frame steers is 10.2% protein. Medium- and large-frame steers weighing 1,100 lb and gaining weight at 2.2 lb daily require 9.5% protein in the diet.

The zinc requirement of steers …

Block And Bridle Annual, 1988

Block and Bridle Student Organization

Table of Contents:

Purpose and Emblem
Presidents letter
Calendar
Meetings
Treasurer's Report
Advisors
Faculty
Graduate Students and Secretaries
Members
Initiates
Officers
Executive Committee
Liaison
Seniors
State Fair Awards
Tyson Chicken Kitchen
Little AK-SAR-BEN
Kids Day
Meats Judging Contest
Christmas Coffee
M.A.E.C.
Regional Meetings
Ham Sales
Quadrathalon
Queen Coronation
Brands
Beef Show
Pizza Feed
Quarterhorse Show
Livestock Judging Contest
Bake Sale
Spring Picnic
Scenes From Nebraska
Livestock Judging Team
Meats Judging Team
Horse Judging Team
Faculty
Honoree
Member Awards
Advertisers
Editors Comments
Index of Advertisers

Perspectives On Process In Plant Virology, Myron K. Brakke

Department of Plant Pathology: Faculty Publications

The editors asked that I write a chapter on landmarks in plant virology, a topic that has been covered by several authors, for example by Henderson Smith (89), Bawden (9), Holmes (51), Markham (62), Harrison (44), Black (12), and Matthews (64). In 1 938, the first of these authors, Henderson Smith (89), divided his presidential address to the Society for Applied Biology between the control of plant-virus diseases and the nature of plant viruses. Progress since then has been much more rapid in the latter than in the former area. Henderson Smith could easily understand today's literature on losses, control, …

A Non-Capsid Protein Associated With Unencapsidated Virus Rna In Barley Infected With Barley Stripe Mosaic Virus, Myron K. Brakke, E. M. Ball, W. G. Langenberg

Department of Plant Pathology: Faculty Publications

Barley tissue with an acute systemic infection of barley stripe mosaic virus contained a large amount of unencapsidated virus RNA which was stable in extracts made in ribosome isolation buffer. The virus RNA in ribosome preparations sedimented in a broad band at 80S to 100S in sucrose gradients, which is less than the virion sedimentation rate of 180S to 200S. A protein of apparent M_r 60 000, which sedimented with the virus RNA, was present in ribosome extracts from infected plants but absent from those from uninfected plants. The protein is probably a virus protein because its apparent molecular …

Effect Of Wheat Streak Mosaic Virus Infection On Total Dna And Chloroplast Ribosomal Rna In Wheat Leaves, Myron K. Brakke, J. L. White, R. G. Samson, J. Joshi

Department of Plant Pathology: Faculty Publications

The amount of chloroplast 23s rRNA relative to either DNA or to cytoplasmic 28s rRNA was reduced in young wheat leaves infected with wheat streak mosaic virus.
ChlorophyiJ was reduced in infected leaves. Fresh weight per leaf and DNA content per leaf were reduced in infected leaves, but DNA per g was increased.
Cytoplasmic ribosomal RN.A appeared to degrade more slowly during senescence in infected leaves than in uninfected. Virus was undetectable by density gradient centrifugation in systemicaliy infected leaves less than 6 cm long and reached its highest concentration when young leaves reached their maximum size. Mosaic developed in …

Comparisons Of Mitochondrial Dna From The Sibling Species Heterodera Glycines And H. Schachtii, A. D. Radice, Thomas O. Powers, Laurie J. Sandall, R. D. Riggs

Department of Plant Pathology: Faculty Publications

Restriction fragment patterns of mitochondrial DNA from sibling species of cyst nematodes Heterodera glycines and H. schachtii were examined. Fourteen restriction endonucleases recognizing four, five, and six base-pair sequences yielded a total of 90 scorable fragments of which 10% were shared by both species. Mitochondrial genome sizes for H. glycines and H. schachtii were estimated to be 22.5-23.5 kb and 23.0 kb, respectively. A single wild type mitochondrial genome was identified in all populations of H. glycines examined, although other mitochondrial genomes were present in some populations. The H. schachtii genome exhibited 57 scorable fragments, compared with 33 identified in …

Adoption Of Newly-Mated Queens: A Mechanism For Proliferation And Perpetuation Of Polygynous Red Imported Fire Ants, B. Michael Glancey, Clifford S. Lofgren

Entomology Papers from Other Sources

The polygynous form of the red imported fire ant, Solenopsis invicta Buren was first reported from Mississippi in 1973; however, the source of the numerous fertile queens in polygynous colonies has remained an enigma. In 1987, 400 queens from a mating flight were marked with a durable paint and released in an area heavily populated with the polygynous form. None were recaptured after one week, but 9 months later, 4 clearly-marked queens were found in a nest 65 meters from their release point. This finding clearly points to adoption. About 5 weeks later, 37 of 107 fertile queens collected from …

Use Of Chemical Characters In Defining Populations Of Fire Ants, Robert K. Vander Meer, Clifford S. Lofgren

Entomology Papers from Other Sources

The fire ants, Solenopsis invicta and S. richteri, were accidentally imported into the United States in the first half of this century from South America. In their adopted habitat the imported fire ants have thrived causing considerable medical and agricultural problems in the nine widely infested states of the south and southeast. The red imported fire ant, S. invicta was considered the dominant ant in the infested areas, having displaced the black imported fire ant, S. richteri, into a small enclave in north- eastern Mississippi. However, a large reproductively viable S. invicta/S. richteri hybrid population was recently …

Descriptions Of Pupae Of South American Robber Flies (Diptera: Asilidae), D. Steve Dennisi, Lloyd Knutson

Entomology Papers from Other Sources

The pupae of four South American species of robber flies, Diogmites vulgaris Carrera, Mallophora ruficauda (Wiedemann), Mallophora sylverii Macquart, and Triorla striola (F.), are described and illustrated. The pupae of these species are compared morphologically with those of North American species of the same genera. A key to pupae of Asilidae at the subfamily level is provided. Biological notes associated with the specimens examined and with those of Pseudorus distendens (Wiedemann) indicate that the larvae prey upon immature stages of Scarabaeidae (Dyscinetus rugifrons LeConte for D. vulgaris and M. sylverii, Cyclocephala signaticollis Burmeister for M. ruficauda, and a …

Anatomy Of The Ventral Eversible Gland Of Fall Armyworm, Spodoptera Jrugiperda (Lepidoptera: Noctuidae), Larvae, O. G. Marti, C. E. Rogers

Entomology Papers from Other Sources

The ventral eversible gland (VEG) of the fifth instar fall armyworm, Spodoptera frugiperda (J. E. Smith), is described and illustrated. The orifice of the VEG is a transverse slit anterior to the prothoracic legs. An increase in hemocoelic pressure everts the VEG, and the action of six pairs of retractor muscles inverts it. The VEG consists of two functionally different regions-a noneversible glandular sac lined with secretory cells, and an eversible cuticular tube which, when everted, forms a visible, external papilla. Eversion is pleurecbolic, occurring by movement of the sides of the cuticular tube rather than the apex, in response …

Gonotrophic Development In Hypoderma Lineatum And H. Bovis (Diptera: Oestridae), With Notes On Reproductive Capacity, P. J. Scholl, J. Weintraub

Entomology Papers from Other Sources

Gonotrophic development in Hypoderma lineatum (Villers) and Hypoderma bovis (L.) is characterized by initiation and complete growth in larval and pupal stages. Developing oocytes through six stages to the definitive egg are described. Polytrophic ovarian development is modified; only primary and secondary complements of eggs survive and develop simultaneously. The female emerges from the puparium with its life-long complement of eggs fully developed. Capability to mate and immediately oviposit on host cattle is well suited to the short life span of the nonfeeding fly. Mean reproductive capacity of H. lineatum is 516 ± 54 (SD) eggs, significantly higher than the …

Electrophoretic Monomorphism In Six Biotypes And Two Populations Of The Hessian Fly (Diptera: Cecidomyiidae), Stanley G. Wells, Daniel J. Howard, Julie L. Adams, Jonathan Arnold

Entomology Papers from Other Sources

Six biotype bulk populations and two geographic populations of the Hessian fly, Mayetiola destructor (Say), were analyzed at 15 presumptive genetic loci using starch gel electrophoresis. Fourteen of the 15 loci appeared monomorphic. One locus, Pgi, varied in biotypes B, E, and a population from Mason, Mich. The level of genetic variation among Hessian fly populations is among the lowest reported for insects. Genetic differentiation among Hessian fly biotypes and populations is also low, ranging from a Nei's D of 0.000 to 0.002. Protein electrophoresis does not appear to provide a quick procedure to identify Hessian fly biotypes.

Ultrastructural Studies Of The Abdominal Plaques Of Some Diptera, John G. Stoffolano, Jr.,, Norman E. Woodley, Art Borkent, Lucy R. S. Yin

Entomology Papers from Other Sources

Light microscopy revealed cuticular plaques restricted to the abdomens of both sexes of four species of brachycerous flies: Tabanus nigrovittatus Macquart, Apiocera barri Cazier, Hydrophorus viridiflos (Walker), and Dolichopus consanguineus (Wheeler). Using SEM, these plaques proved glabrous and unsculptured. Only at high magnification did they show small pits. TEM of the plaques showed the cuticle in this region is traversed by numerous muscle attachment fibers which extend from just below the epicuticle to the base of the cuticle, where they connect to the microtubules of the tendinous epidermal cells. These fibers or tonofibrillae serve as the attachment sites for underlying …

The Nesting Biology Of Colletes Kincaidii Cockerell (Hymenoptera: Colletidae) And Development Of Its Immature Forms, P. F. Torchio, G. E. Trostle, D. J. Burdick

Entomology Papers from Other Sources

Overwintering larvae of Colletes kincaidii Cockerell were obtained by removing soil blocks from a large nesting site established in a hardened, vertical sandstone cliff at Bonny Doon, Calif. One sandstone block was placed in a greenhouse at Logan, Utah, where two emerging females established nests within glass tubes inserted into observation boxes and one female excavated a nest in soil beneath the sandstone block from which she emerged. Observations of nesting biology in glass tube nests showed for the first time that polyester cell linings are composed of a mixture of salivary and Dufour's gland materials. Salivary secretion is first …

Tephritid Olfaction: Morphology Of The Antennae Of Four Tropical Species Of Economic Importance (Diptera: Tephritidae), J. C. Dickens, W. G. Hart, D. M. Light, E. B. Jang

Entomology Papers from Other Sources

Four types of sensilla are present on the antennal surface of four tropical tephritid species of economic importance-the Mexican fruit fly, Anastrepha ludens (Loew); the Mediterranean fruit fly, Ceratitis capitata (Wiedemann); the melon fly, Dacus cucurbitae Coquillett; and the oriental fruit fly, D. dorsalis Hendel. Three types of porous sensilla occur only on the funiculus. Two types of multi porous pitted sensilla (MPS)-thick-walled and thin-walled-house dendritic branches, and both are probably chemoreceptors. Electrophysiological recordings from cells associated with a thick-walled MPS in C. capitata showed that it responds to trimedlure, a known attractant. Multiporous grooved sensilla also occurring on the …

Queen Pheromone Production And Its Physiological Correlates In Fire Ant Queens (Hymenoptera: Formicidae) Treated With Fenoxycarb, Martin S. Obin, B. Michael Glancey, W. A. Banks, Robert K. Vander Meer

Entomology Papers from Other Sources

Biological assays were used to evaluate the effect of the insect growth regulator fenoxycarb (ethyl (2-p-phenoxyphenoxy) ethyl carbamate) on production of queen-derived dealation inhibitory pheromone and the queen recognition pheromone of Solenopsis invicta Buren. Treated virgin and mated queens weighed less and were less capable of inhibiting dealation by female alates than were nontreated controls. Virgin queens that gained weight during the experimental trials produced more dealation inhibitory pheromone and more queen recognition pheromone than virgin queens that lost weight. Treated virgin queens with fenoxycarb-induced ovary dysfunction inhibited de alation in proportionally fewer alates than treated virgin queens of similar …

Quantitative Analysis Of Temperature., Moisture., And Diet Factors Affecting Insect Development, David W. Hagstrum, George A. Milliken

Entomology Papers from Other Sources

Extensive published data on the developmental times of nine species of stored-product Coleoptera in relation to temperature, moisture, and diet were described by regression equations. At most temperatures, the order of relative influence of these factors on development was temperature > moisture > diet. However, moisture and diet influenced larval development more than temperature near the optimal temperature for development of each species. Egg, larval, and pupal stage durations at 27°C averaged 15, 66, and 19% of the total developmental time, respectively, at moistures above 12%, and 12, 72, and 15% of total developmental time at moistures below 12%. Similar percentages were …