Life Sciences Commons^™

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), …

Rotating Biological Contractors As An Effective Removal System Of Waste Petroleum Hydrocarbons From Untreated Wastewaters, John Tanacredi Ph.D., R. C. Cardenas

Faculty Works: CERCOM

A staged, partially submerged rotating biological disk system was assessed to determine its performance in the reduction of detectable concentrations of polynuclear aromatic hydrocarbons (PAH0 attributable to waste crankcase oils (WCCO) in wastewater effluent. Results indicate that such biological systems for the removal of WCCO aromatic hydrocarbons may be a viable alternative to secondary treatment systems commonly being employed.

Effects Of Moonlight And Daylight On Hydroacoustic Estimates Of Pelagic Fish Abundance, Chris Luecke, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

To determine how moonlight and daylight affect hydroacoustic estimates of fish abundance, we used a dual-beam transducer and echo integration to survey pelagic fish (primarily Bonneville ciscoes Prosopium gemmifer) in Bear Lake, Utah and Idaho. During the new moon, the fish were dispersed (not schooling) below the thermocline, chiefly at the depths of 10–20 m. At full moon, they were dispersed but much closer to the bottom, where they were difficult to detect. Acoustic estimates offish density and biomass during full moons were approximately 50% of values derived during new moons. A diel survey during a new moon indicated that …

An Empirical Model Of Gastric Evacuation Rates For Fish And An Analysis Of Digestion In Piscivorous Brown Trout, E. He, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

The gastric evacuation rates of brown trout Salmo trutta (0.9–1.6 kg) feeding on fingerling rainbow trout Oncorhynchus mykiss (3.5–7.6 g) were measured in the laboratory at five temperatures (4.5, 9.0, 14.0, 19.0, and 22.5°C). Instantaneous gut evacuation rates (Re) increased exponentially with temperature (T): Re = 0.053se^0.073T, r^2 = 0.98; they varyied from 7%sh^–1 at 4.5°C to 29%sh^–1 at 22.5°C. Linear regressions described the relationship between time and qualitative measures of fish digestion, thus allowing investigators to determine how long an ingested fish would be identifiable at different temperatures. An analysis of published evacuation rates (N = 121) of 22 …

1993 Beef Cattle Report

Nebraska Beef Cattle Reports

Cow-Calf • Forage Systems Using Sandhills Subirrigated Meadows and Range: Beef Production Traits • Forage Systems Using Sandhills Subirrigated Meadows and Range: Economic Analysis • High Quality Meadow Hay as a Winter Supplement for Gestating Beef Cows in the Sandhills of Nebraska • Heifers Sired by Bulls with Either High or Low EPD's for Marbling Do Not Differ in Age at Puberty • Synovex C Affects Growth, Reproduction, and Calving in Heifers • Synthetic Progestins Influence Secretion of Luteinizing and Timing of Ovulation • Level of Progesterone Influences Pregnancy Rate in Beef Cows and Heifers • Combination of Factors (Ratios) …

Acceleration Of Postmortem Tenderization In Brahman-Cross Beef Carcasses By Calcium Chloride, Mohammad Koohmaraie, Georgianna Whipple, John D. Crouse

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

The recently completed National Tenderness Survey and Beef Quality Audit have clearly demonstrated that variation in beef tenderness at the consumer level is one of the major problems that face the meat industry. Because of this, and since consumers consider tenderness to be the principal component of meat quality, scientists in the Meats Research Unit of U.S. Meat Animal Research Center have placed a special emphasis on understanding factors that determine beef tenderness.

To enhance tenderness, meat is normally aged (as wholesale cuts or carcasses). During this aging period a number of changes occur in the meat which result in …

Bos Indicus Breeding Effects On Muscle Characteristics And Their Relationship With Meat Tenderness, Georgianna Whipple, Mohammad Koohmaraie, Michael E. Dikeman, John D. Crouse, Melvin C. Hunt

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

Variation in meat tenderness that exists among animals may be due to genetics, diet, age, and other factors. Results from the Germplasm Evaluation (GPE) program show that rib eye steaks from many of the Bos indicus breeds of cattle are less tender than steaks from most of the European (Bos taurus) breeds of cattle, although Bas indicus crossbreeding programs are advantageous due to hybrid vigor and insect and heat resistance in subtropical regions. Because consumers consider tenderness to be the principal component of cooked beef quality, it is important to determine the biological factors that regulate meat tenderness. …

Bovine Embryos From Bluetongue Infected Donors Did Not Transmit Virus To Susceptible Recipients, John A. Acree, Sherrill E. Echternkamp, Steve M. Kappes, Gary S. Ross, Albert J. Luedke, James E. Pearson

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

The recent development of methodology for the successful cryopreservation (Le., ultra low temperature freezing) of bovine embryos has expanded the opportunities for international movement of bovine embryos and has facilitated the exchange of germplasm within and among countries. Unfortunately, frozen embryos also provide an excellent vehicle for the distribution of pathogenic agents (e.g., bluetongue virus, foot and mouth disease, etc.) between livestock populations and between countries. Most pathogens that are on the surface of an embryo with an intact zona pellucida (a translucent mucopolysaccharide shell surrounding the embryo) can be removed by washing. The washing procedure consists of subjecting the …

Comparisons Of Bos Indicus And Bos Taurus Inheritance For Carcass Beef Characteristics And Meat Palatability, John D. Crouse, Larry V. Cundiff, Robert M. Koch, Mohammad Koohmaraie, Steve C. Seideman

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

Crossbreeding is used widely to exploit heterosis and additive genetic variation among breeds to improve efficiency of beef production. The economic value of Bos indicus breeds of cattle, primarily Brahman, in crossbreeding programs in subtropical and tropical climates has been well established. In the temperate climatic conditions of U.S. Meat Animal Research Center, productivity of Bos indicus x Bos taurus F₁ crossbred cows has been outstanding for reproduction an matemal performance relative to that of Bos taurus x Bos taurus F₁ cross cows when mated to produce terminal-cross calves by Red Poll or Simmental sires. (Brahman and Sahiwal …

A Calcium Chloride Injection Process To Produce Guaranteed Tender And Calcium Fortified Meat, Tommy L. Wheeler, Mohammad Koohmaraie, John D. Crouse

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

The recently completed National Beef Tenderness Survey revealed that current beef production practices result in considerable variation in meat tenderness and an unacceptable percentage of tough meat, particularly round and chuck cuts. It has been known for several years that meat from Bos indicus cattle was tougher than meat from Bos taurus cattle and that Bos indicus-influenced cattle make up approximately 25% of the beef cattle in the U.S. In addition, as the beef industry moves towards leaner beef, many production systems that decrease fatness also result in decreased tenderness (i.e., bulls vs steers, forage feeding, growth promotants). Furthermore, …

Cycle V Of The Germplasm Evaluation (Gpe) Program In Beef Cattle, Larry V. Cundiff, Keith E. Gregory, Robert M. Koch

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

Results from the first four cycles of the Germplasm Evaluation (GPE) Program at U.S. Meat Animal Research Center demonstrated that vast genetic variation exits among and within breeds for most bioeconomic traits in beef cattle. The range for differences between breeds was comparable in magnitude to the range in breeding value of individuals within breeds for most traits. Thus, significant genetic change can result from selection both between and within breeds. Breeds can be selected to optimize performance levels for important bioeconomic traits with a high level of precision much more quickly than intrapopulation selection.

No single breed or biological …

Effect Of Method Of Estrous Synchronization On Oocyte Quality And Follicular Insulin- Like Growth Factor (Igf-I), Thomas H. Wise, Ralph R. Murer

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

Of the two methodologies utilized in the beef industry to synchronize animals to estrus (prostaglandin regression of the corpus luteum or implanting/injecting progestin which results in estrus 48-60 hr after implant removal), conception and fertility are generally lower in progestin synchronization to estrus. Both technologies produce comparable results in relation to estrus and ovulation. Alterations in steroidal hormones of the follicle (progesterone/estradiol) are important in the maturation and quality of oocytes. Insulin-like growth factor (IGF-I) which can regulate follicular progesterone concentrations, may have a role in oocyte maturation and viability. Circulating progesterone concentrations alter luteinizing hormone (LH) pulse frequency and …

Contributions Of Ovum Cytoplasm And Uterine Environment And Postnatal Environment To Maternal Effects In Beef Cattle, Keith E. Gregory, Ralph R. Maurer

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

Any contribution or influence on offspring phenotype attributable to its dam, exceeding the inherited sample half of the dam's nuclear genes, is a maternal effect. Maternal effects can be classified into prenatal (e.g., cytoplasmic and uterine components) and postnatal [e.g., lactation, method of rearing (early weaning), plus other postnatal maternal components]. This experiment was designed with two objectives. The first objective was to determine the relative contributions of ovum cytoplasm and uterine influences on prenatal maternal effects by use of embryo transfer (ET). The second objective was to estimate breed differences in prenatal and postnatal maternal effects combined by evaluating …

Differences Among Parental Breeds In Germplasm Utilizationproject, Keith E. Gregory, Larry V. Cundiff, Robert M. Koch, Donald D. Lunstra

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

Large differences exist among breeds for most bioeconomic traits. These differences are the result of different selection goals in different breeds. Thus, over time, large genetic differences have accumulated among breeds. Results from the Germplasm Evaluation Program at the U.S. Meat Animal Research Center provide evidence that genetic variation between breeds is of similar magnitude to genetic variation within breeds for many bioeconomic traits. However, the heritability of breed differences approaches 100%, whereas, the heritability of differences within breeds for major bioeconomic traits varies from less than 10% to about 50% depending on the trait. Heritability of breed differences approaches …

Effects Of A Β-Agonist On Muscle Protein Degradation, Enzyme Activity, And Meat Tenderness In Steers, Tommy L. Wheeler, Mohammad Koohmaraie

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

It is generally accepted that muscle proteins are under continual degradation during normal growth. It has been estimated that 15 to 22% of the animal's total energy expenditure is for this muscle protein turnover. Regulation of the rate of muscle protein degradation could cause dramatic changes in rate and efficiency of muscle growth. Despite their importance in muscle growth, the mechanisms and control of skeletal muscle protein degradation are unknown. It has been hypothesized that several enzyme systems are involved at different stages of degradation, and that the calpain enzyme system (which occurs naturally in muscle) may initiate protein degradation …

Energy Expenditures Of Mature Cows During The Production Cycle, Calvin L. Ferrell, Tom G. Jenkins

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

The cow uses about 65% of the feed energy used in the production of beef cattle. Of that, about 74% is used for maintenance of the maternal body, 18% for lactation and 8% for pregnancy in the mature, producing beef cow. The growing- finishing animal uses about 35% of the total feed energy used for beef production. In the growing-finishing animal, maintenance costs may vary from 30 to 100% of the total feed energy consumed, with the lower proportion being at high intakes and rates of gain. Typically, in feedlot cattle this value ranges from 30 to 40%, whereas in …

Estimates Of Genetic And Phenotypic Parameters Of Pelvic Measures, Weight, Height, Calf Birth Weight, And Dystocia In Beef Cattle, Keith E. Gregory, Larry V. Cundiff, Robert M. Koch

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

Based on requirements for assistance at first parturition as two-year-olds, experimental results document the importance of dystocia in major breeds of Bos taurus cattle. In addition to the greater labor and managerial requirements associated with dystocia (calving difficulty), experimental results show that dystocia results in reduced perinatal calf survival and reduced conception rate in females in the subsequent breeding season when dystocia is experienced. There is not agreement on the value of pelvic measures as a predictor of dystocia at first parturition. Information is limited on the genetic relationship between pelvic measures and other factors that may be genetically associated …

Factors Influencing Fetal Growth And Birth Weight In Cattle, Calvin L. Ferrell

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

Fetal growth, as indicated by birth weight, has important influences on animal production. Birth weights lower than optimum are associated with reduced energy reserves, lowered thermoregulatory capability, and increased calf deaths at or near birth. In addition, low birth weights are related to low rates of growth after birth and decreased mature size. Conversely, birth weights greater than optimum are associated with greater calving difficulty. Primarily because of the increased calving difficulty, calf losses at birth and difficulties if rebreeding the cow are increased.

Fetal growth, hence birth weight, is influenced by numerous factors including number of fetuses, sex, parity …

Factors Involved In Regulating The Development Of Ovarian Follicles In Cattle, Andrew J. Roberts, Sherrill E. Echternkamp, Judith M. Grizzle, Thomas H. Wise

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

The inability to regulate ovarian follicular development is a major obstacle to improving reproductive efficiency in cattle whether the objective be estrous cycle regulation, multiple ovulations and births, superovulation for embryo transfer, a shorter postpartum anestrous period or younger age at puberty. Similarly, normal growth and selection of ovulatory follicles are required for sexual behavior, for maturation and release of viable oocytes and for preparation of the uterine environment for gamete transport, fertilization and embryonic development. Increasing reproductive efficiency is critical to increasing livestock production as reproductive losses in cattle range from 20 to 35%. Research outlined in this report …

Characteristics Of Diverse Breeds In Cycle Iv Of The Cattle Germplasm Evaluation Program, Larry V. Cundiff, R. M. Koch, Keith E. Gregory, John D. Crouse, Michael E. Dikeman

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 new composite breeds and to match genetic potential with diverse markets, feed resources and climates. This report presents preliminary results from an ongoing study at the Roman L. Hruska U.S. Meat Animal Research Center (U.S. Meat Animal Research Center)to characterize breeds of cattle representing diverse biological types for bioeconomic traits that influence quantity and value of production.

Follicular Hormonal Changes And Oocyte Quality In Heifers That Exhibited An Lh Surge, No Lh Surge, Or In Which The Lh Surge Was Suppressed With Progestin, Calvin L. Ferrell, Thomas G. Jenkins

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

The mechanisms that control follicular development, oocyte maturation and ovulation, are complex and poorly understood in farm animals. Superovulation via gonadotrophin stimulation of the ovaries provides a model to study follicular development and ovulation and the endocrine interactions at the follicle level. This study focused on the importance of luteinizing hormone (LH) in follicular development, hormonal secretion, and ovulation. The objectives of this study were to describe differences in follicular development, hormonal secretion, and oocyte quality in superovulated heifers that exhibited a normal LH surge, no LH surge, and in which the LH surge was suppressed with a progestin implant.

Effect Of Castration On Skeletal Muscle Protein Turnover And Muscle Enzyme Activities In Cattle, Tommy L. Wheeler, J. Brad Morgan, Mohammad Koohmaraie, John D. Crouse, Jeff W. Savell

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

It is well established that proteins are continually synthesized and degraded in skeletal muscle, but the proteolytic enzymes involved in muscle protein degradation remain unknown. It is hypothesized that the calpain proteolytic system, which is known to be important in postmortem protein degradation and thus in meat tenderization, could also be involved in or even possibly initiate muscle protein degradation in the living animal.

It is well documented that intact males grow more rapidly (15 to 17%), utilize feed more efficiently (10 to 13%) and produce higher yielding carcasses with less fat and more lean meat than castrates. However, the …

Effect Of Marbling Degree On Palatability And Caloric Content Of Beef, Tommy L. Wheeler, Larry V. Cundiff, Robert M. Koch

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

The relationship of marbling to beef palatability has been the subject of numerous investigations and several review papers. A vast majority of the data on this subject indicate that there is a positive relationship between marbling degree (or percentage chemical fat) and tenderness, juiciness, and flavor intensity, and an inverse relationship with Warner-Bratzler shear force (a mechanical measure of tenderness). However, this relationship is weak at best. Generally, although tenderness may increase linearly as marbling increases, the increments are very small, particularly from one marbling degree to the next. A comparison of the extremes in USDA quality grade (e.g., Standard …

Heat And Moisture Production And Dissipation In Beef Cattle, John A. Nienaber, G. Leroy Hahn, Anders Ehrlemark

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

Calorimetry or the measurement of heat transfer between animals and the environment has been conducted at U.S. Meat Animal Research Center for several years. The primary objective of calorimetry has been the evaluation of maintenance energy requirements of animals. For cattle, maintenance requirements for either lactation or growth have been of interest.

Calorimetry can also provide information useful in evaluating heat dissipation by animals in various environments. Recent measurements were completed at U.S. Meat Animal Research Center by a Swedish engineer to provide answers to a beef housing problem. Current information has proven to be inadequate for the design of …

Identification Of Twin Pregnancies In Cattle By Ultrasonography, Sherrill E. Echternkamp, Keith E. Gregory

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

The increased twinning frequency (Le., approximately 25%) in the U.S. Meat Animal Research Center twinning project has resulted in additional management requirements to achieve survival of twin calves and timely rebreeding of their dams. Previously, neonatal survival of twin calves (Le., within 24 hr after calving) was about 82% compared to 97% survival for singleborn calves. Although twin calves are smaller at birth than single-born calves (34.3 vs 44.8 kg), the incidence of calving difficulty (dystocia) is increased in twin pregnancies (35% vs 23% for twins vs singles, respectively) due to abnormal positioning of the calves within the uterus. The …

Improving The Microbiological Quality Of Meat, James S. Dickson, Gregory R. Siragusa

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

Microbial contamination of animal carcasses is a result of the necessary procedures required to process live animals into retail meat. The contamination can be minimized by good manufacturing processes, but the total elimination of bacteria of public health significance is difficult, if not impossible. A variety of methods have been developed to improve the microbiological quality of meat, although most of the current methods focus on washing and sanitizing the carcasses, prior to chilling.

The beef slaughter process begins by humanely stunning the animal, bleeding, and then removing the hooves and head. The hide is removed, and the carcass is …

Is Fiber Digestion In The Rumen Reduced By Catabolite Repression?, Kevin L. Anderson, Vincent H. Varel

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

Bacteria which degrade cellulose play a key role in animal digestion of plant material. As with all bacteria, these cellulolytic bacteria are able to regulate their growth and enzymatic activity by a number of mechanisms. One of these regulatory mechanisms may be catabolite repression.

This repression refers to the ability of certain bacteria to stop the metabolism of one substrate in preference to a second substrate. Sometimes termed "glucose effect," this repression is observed, for example, as the bacterium Escherichia coli grows on lactose. When glucose is then added to the growth medium, E. coli will stop utilizing lactose and …

Meat Tenderness And The Calpain Enzyme System In Young Bulls And Steers, Tommy L. Wheeler, J. Brad Morgan, Mohammad Koohmaraie, Jeff W. Savell, John D. Crouse

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

Comparisons of meat palatability between bulls and steers have indicated that meat from young bulls is more variable in tenderness. In addition, meat from bulls is usually numerically less tender, although the difference is frequently not statistically significant. This indicates that meat from bulls is only slightly, but consistently less tender than meat from steers.

Numerous studies have attempted to link bull meat toughness to higher amounts and decreased solubility of connective tissue. However, it has been reported that this change in bull meat does not occur until 12 to 16 mo of age. It has been shown conclusively, using …

Predicting The Growth Of Salmonellae On Beef, James S. Dickson, Gregory R. Siragusa, James E. Wray Jr.

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

Bacterial contamination of fresh meats can occur during normal slaughter and handling procedures, although this contamination can be minimized by adhering to good hygienic practices during slaughter. Since the bacteria are confined almost exclusively to the carcass surface as compared to the deep muscle tissue, procedures which can control the survival and growth of bacteria on tissue surfaces are of interest to both the meat industry and regulatory agencies. Chilling, either by forced air or water spray systems, is used universally to reduce the growth of bacteria on animal carcasses. However, because of the initial heat in an animal carcass, …

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 …