Life Sciences Commons^™

Genes Of The Major Histocompatibility Complex In Cattle, Roger T. Stone, Noelle E. Muggli-Cockett

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

The search for simple genetic traits that can be used as markers to predict variation in more complex genetic traits has been ongoing for several decades. For a given gene to be useful as a marker, it must have multiple forms, alleles, that are readily identifiable. Also, the frequency for the different alleles of the gene in a population must be such that most animals have two forms of the gene instead of one, otherwise statistical analysis is difficult. Only a few relationships between markers and production traits reported thus far have been utilized in production practices, presumably because of …

Scrotal Thermography As A Tool For Predicting Semen Quality And Natural-Mating Fertility In Young Beef Bulls, Donald D. Lunstra, Glenn H. Coulter

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

The scientific literature offers only sparse information on mechanisms controlling reproductive function in beef bulls and indicates that there are very few consistent relationships between the commonly evaluated male reproductive characteristics and variations in natural-mating fertility of beef bulls. Current techniques for evaluating and predicting reproductive potential of bulls are ineffective, and the beef cattle industry selects breeding males on the basis of appearance, growth rate, size, and other factors of little relationship to reproductive potential. Reproductive merit is five times more important economically than is growth performance and at least ten times more important than product quality for the …

The Effectiveness Of Subjecting Bos Indicus Crossbred Beef Carcasses To Higher Temperatures To Improve Tenderness, Georgianna Whipple, Mohammad Koohmaraie, Michael E. Dikeman, John D. Crouse

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

Many studies have evaluated changes that occur in muscle during the aging process and how they relate to meat tenderness. Other research has shown that subjecting carcasses to higher temperatures soon after slaughter speeds the aging process that ultimately results in improved tenderness. Several things may explain this effect. The higher temperature causes the pH (acidity) of the muscle to decrease faster. Also, the combination of lower pH and higher temperature could promote an earlier release of calcium into the muscle, which normally occurs in muscle tissue after slaughter. This increase in calcium concentration in turn activates the calpain enzyme …

Germplasm Utilization In Beef Cattle, Keith E. Gregory, Larry V. Cundiff, Robert M. Koch, Donald D. Lunstra

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

Heterosis achieved through continuous crossbreeding can be used to increase weight of calf weaned per cow exposed to breeding by 20%. Comprehensive programs of breed characterization have revealed large differences among breeds for most bioeconomic traits. About 55% of the U.S. beef breeding population involving 93% of the farmers and ranchers who produce beef cattle are in production units of 100 or fewer cows. Optimum crossbreeding systems are difficult to adapt in herds that use fewer than four bulls. Further, fluctuation in breed composition between generations in rotational crossbreeding systems can result in considerable variation among both cows and calves …

Use Of Calcium Alginate To Immobilize Antimicrobial Agents On Beef Tissue, Gregory R. Siragusa, James S. Dickson

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

Even under the best of slaughtering and processing conditions, beef carcasses will become naturally contaminated with some bacteria from the animal's hide, hair, hooves, and the abattoir environment. This contamination is mostly composed of bacteria which are harmless, but which can ultimately cause spoilage of the beef. The shelflife of raw beef is largely determined by the numbers and types of these bacteria. Since some bacterial contamination will always be present on beef, it is desirable to reduce these numbers to decrease the rate of spoilage, increase refrigerated shelflife, and further ensure the microbiological safety of raw beef before consumption. …

Use Of Crossbreeding And Breed Differences To Meet Specific Targets For Production And Carcass Traits Of Beef Cattle, Keith E. Gregory, Larry V. Cundiff, Robert M. Koch

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

The specific requirements for effective use of breed differences to meet specific production and market requirements are: (1) accurate assessment of production resources in regard to availability and costs, (2) accurate assessment of market requirements; Le., value differences in carcass composition associated with yield grade and quality grade, and (3) accurate current characterization of breeds in regard to such traits as: (a) growth rate and size, (b) carcass composition, (c) milk production, and (d) age at puberty. This information is needed to identify contributing breeds to use in alternative mating systems to achieve specific targets for production and carcass traits. …

The Relationship Of Metabolic Hormones, Nutrition, And Postpartum Anestrus In Different Biological Types Of Cattle, Andrew J. Roberts, Russell A. Nugent Iii, Thomas G. Jenkins, John M. Klindt

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

Restricted energy intake can suppress the overall productivity of cattle. Restricted energy intake can decrease overall productivity of beef cows through, among other traits, decreased milk production, calf performance, and reproduction. However, failure of a cow to conceive is the major component affecting the overall production efficiency of the cow herd. In a companion report included in this publication ("Postpartum Interval Is Influenced by Nutritional Environment and Biological Type"), we demonstrated that the postpartum intervals for breeds of cattle with different genetic potentials for growth and milk production were differentially affected by restricted energy availability. This report, along with numerous …

Relationships Of Thymic Peptides Thymosin Α1 And Β4 With Reproductive Status: Puberty And Estrus, Thomas H. Wise, Michael L. Day, James E. Kinder, Ralph R. Maurer

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

The thymus gland has been analyzed in depth in relation to its immunological function, but new evidence is accumulating that the thymus and its endocrine secretions (interferons, interleukins, thymic peptides) may be required for normal reproduction. The thymus gland regresses at puberty and pregnancy, indicative of the effect of gonadal steroids on the gland. Steroidal interactions have been hypothesized to mediate the secretion of some thymic peptides. Thymosin β₄, a thymic peptide, seems to have an integrative role in gonadal function by promoting the release of gonadotrophin releasing hormone whereas thymosin α₁ causes the release of adrenocorticotrophin …

Superovulation Of Cows By Initiating Fsh Treatments During The First Few Days After Estrus, Andrew J. Roberts, Sherrill E. Echternkamp

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

Superovulation of cattle is a technique being used in conjunction with embryo transfer to expedite the propagation of animals with genetic merit for desirable traits. Briefly, these techniques involve the induction of multiple ovulations during one estrous cycle by administering multiple injections of a hormone called follicle stimulating hormone (FSH). Under ideal conditions this treatment will result in multiple embryos. These embryos can then be collected from the cow and transferred to recipient cows of lesser value, which act as surrogate dams. These techniques allow the production of many calves from one cow within a year as opposed to the …

Background Contaminants Evaluation Of The Republican River Drainage Colorado, Kansas, And Nebraska

United States Fish and Wildlife: Staff Publications

This study was conducted to determine background levels of metals and organochlorine compounds in aquatic habitats in the Republican River basin, a large watershed in eastern Colorado, eastern Wyoming, southern Nebraska, and northwestern and northcentral Kansas. Reservoirs and their tributaries in the basin are concentration areas for bald eagles, migratory waterfowl, and occasionally for whooping cranes and other federally-listed threatened and endangered wildlife. The sampling was done to assess risk to federal trustee resources that use aquatic habitats in the basin.

We sampled sediments at 29 locations and fish at 30 locations on the Republican River and tributaries in eastern …

Metal And Organic Residues In Addled Eggs Of Least Terns And Piping Plovers In The Platte Valley Of Nebraska, Timothy E. Fannin, Brent J. Eamoil

United States Fish and Wildlife: Staff Publications

The threatened piping plover and the endangered interior least tern breed on the Platte River in Nebraska from the city of North Platte to the confluence with the Missouri River at Plattsmouth (Faanes 1983, Sidle et a/1988).

Major riverine nesting areas are the reaches from Lexington to Grand Island and from Columbus to Plattsmouth (Fig 1). Nesting habitat is sparsely vegetated or unvegetated islands, sandbars, or shorelines of the river.

An additional and important habitat is on the banks and islands within sand pits made by sand and gravel operations along the river.

In the initial nest of the year, …

Sequential Transformation For Multiple Traits For Estimation Of (Co)Variance Components With A Derivative-Free Algorithm For Restricted Maximum Likelihood, L. Dale Van Vleck, K. G. Boldman

Department of Animal Science: Faculty Publications

Transformation of multiple-trait records that undergo sequential selection can be used with derivative-free algorithms to maximize the restricted likelihood in estimation of covariance matrices as with derivative methods. Data transformation with appropriate parts of the Choleski decomposition of the current estimate of the residual covariance matrix results in mixed-model equations that are easily modified from round to round for calculation of the logarithm of the likelihood. The residual sum of squares is the same for transformed and untransformed analyses. Most importantly, the logarithm of the determinant of the untransformed coefficient matrix is an easily determined function of the Choleski decomposition …

An Investigation Of Trace Element Contamination At Bamforth National Wildlife Refuge, Kimberly Dickerson, Pedro Ramirez Jr.

United States Fish and Wildlife: Staff Publications

Bamforth National Wildlife Refuge (Bamforth) located in southeast
Wyoming serves as an important resting area for several species of migratory
waterbirds. Surveys were conducted in the summer months of 1992 to
determine bird use at Bamforth. Sediment, water, and biota were collected
from Bamforth to identify wetlands with potential contaminant problems that
may be affecting migratory waterbirds. Mercury and lead in water samples
were above criteria for the protection of aquatic life. Selenium levels in
vegetation and sediment were elevated above concentrations documented to
bioaccumulate and cause adverse reproductive effects in waterfowl. Selenium
levels in waterbird eggs were slightly greater …

Contaminants In Oil Field Produced Waters Discharged Into The Loch Katrine Wetland Complex, Park County, Wyoming And Their Bioconcentration In The Aquatic Bird Food Chain, Pedro Ramirez Jr.

United States Fish and Wildlife: Staff Publications

The 866-acre Loch Katrine wetland complex in Park County, Wyoming provides habitat for many species of aquatic birds. However, the complex is sustained primarily by oil field produced waters. This study was designed to determine if constituents in oil field produced waters discharged into Loch Katrine pose a risk to aquatic birds inhabiting the wetlands. Trace elements, hydrocarbons and radium-226 concentrations were analyzed in water, sediment and biota collected from the complex during 1992. Boron and radium-226 were present in the produced water discharge and are bioaccumulating in the food chain. Although not present in acute concentrations, elevated boron in …

Nebraska Ornithologists' Union 1993 Spring Meeting, South Sioux City, Nebraska, May 14-16, Todd Jensen

Nebraska Bird Review

Highlights of the 92nd Annual Business Meeting (condensed from notes by Todd Jensen, Secretary).

A special committee was appointed at the 1992 Annual Business Meeting to review and recommend changes in the current Articles of Incorporation, and the current and past Bylaws. These recommendations were presented by President George Brown to the 32 members present. After some debate, a motion was made by Emma Johnson, seconded by Ruth Green, that the Articles of Incorporation recommended by the committee be accepted. Motion carried. A motion was made by Clyde Johnson, seconded by Gary Purdy, that the Bylaws recommended by the committee …

Environmental Effects On Neonatal Mortality Of Beef Calves, S. M. Azzam, J. E. Kinder, Merlyn K. Nielsen, L. A. Werth, K. E. Gregory, Larry V. Cundiff, R. M. Koch

Department of Animal Science: Faculty Publications

Calving records from 1969 to 1989 from the Roman L. Hruska U.S. Meat Animal Research Center were used to investigate how climatic conditions, in addition to dystocia, age of dam, size of calf, and sex affect calf survival from birth to 1 wk of age. Data were analyzed separately for cows calving with (n = 11,094) or without (n = 72,187) dystocia. Neonatal mortality was described by a logit model and parameters were estimated by maximum-likelihood procedures. Calves born to cows with dystocia were five times as likely to die neonatally than calves born without assistance. Of all calves that …

Estimates Of Variances Due To Direct And Maternal Effects For Growth Traits Of Romanov Sheep, G. A. Maria, K. G. Boldman, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Records of growth traits of 2,086 Romanov lambs were used to estimate variance components for an animal model and genetic correlations between growth traits. Traits analyzed were birth weight (BWT), weaning weight (WW), 90-d weight (W90), and daily gain for the periods birth to weaning (DG1) and weaning to 90 d (DG2). Weaning was at approximately 40 d. Variance components were estimated using restricted maximum likelihood with an animal model including fixed effects for year x season, sex, rearing type, and litter size and random effects for the direct genetic effect of the animal (with relative variance h²), …

Spiculopteragia Spiculoptera And S. Asymmetrica (Nematoda: Trichostrongyloidea) From Red Deer (Cervus Elaphus) In Texas, Lora G. Rickard, Eric P. Hoberg, Nancy M. Allen, Gary L. Zimmerman, Thomas M. Craig

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

Specimens of Spiculopteragia spiculoptera and S. asymmetrica were recovered from the abomasa of five of ten naturally infected red deer (Cervus elaphus) in Texas (USA). Female specimens of Spiculopteragia were present in all five animals. Male specimens of S. spiculoptera and S. asymmetrica were present in one of five and three of five red deer, respectively. Spiculopteragia spiculoptera has not previously been recognized in the United States and the present report constitutes the first records of Spiculopteragia spp. in red deer from North America. It is likely that species of Spiculopteragia have been introduced to North America with …

Enteric Coccidia (Apicomplexa) In The Small Intestine Of The Northern Spotted Owl (Strix Occidentalis Caurina), Eric P. Hoberg, R. J. Cawthorn, O. R. Hedstrom

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

Sporulated oocysts (mean dimensions = 13.0 x 10.8 μm) and sporocysts (11.3 x 5.5 μm) of a coccidian resembling Frenkelia sp. or Sarcocystis sp. were present in the lamina propria of the small intestine of a naturally-infected northern spotted owl (Strix occidentalis caurina) collected near Medford, Oregon, USA. Dimensions of these oocysts and sporocysts appear to be considerably smaller than those from other sarcocystid species with avian definitive hosts. Additionally, numerous developmental stages and unsporulated oocysts (mean dimensions 22.8 x 17.8 μm) of a possible species of Isospora also were observed in the intestinal epithelium. This constitutes the …