Animal Sciences Commons^™

Genotype-Environment Interactions For Reproduction And Maternal Performance Of Bos Indicus And Bos Taurus Crosses In Nebraska And Florida, Larry V. Cundiff, Timothy A. Olsen, K. Euclides Filho, M. Kroger, W. T. Butts, Keith E. Gregory

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

In the U.S., cattle of diverse breeds and crosses are maintained in diverse climatic environments ranging from the temperate-continental conditions of the North Central region, characterized by wide fluctuations in temperate from winter to summer, to subtropical conditions of the Southeastern region, characterized by relatively moderate winter temperatures but high temperatures and humidity in the summer mo. The genetic range is spanned by Bos indicus (humped cattle) breeds, that originally evolved under tropical conditions of India and Pakistan, and by Bos taurus (nonhumped) breeds, that originally evolved under temperate conditions of continental Europe and the British Isles. The present experiment …

Gene Mapping In Cattle, Craig W. Beattie, Roger T. Stone, Michael D. Bishop, Sara L. F. Sunden, John W. Keele, Steven M. Kappes

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

Over the last decade, progress in molecular biologic techniques has brought the mapping of genes within the human and mouse genomes to a point where information on the location of groups of genes and additional anonymous, but unique, bits of DNA (markers) within their respective genomes can be brought to bear in developing a bovine genomic map. This is possible because of the conservation of genes, particularly those concerned with regulating important functions, between species into syntenic (single chromosome) groups.

Investment in the development of a bovine map is important for several reasons. While continued selection of desirable traits by …

Hormone Profiles In Cattle Selected For Twin Ovulations And Births, Sherrill E. Echternkamp, Leon J. Spicer, Keith E. Gregory

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

Follicle stimulating hormone (FSH) is secreted into the blood circulatory system by the pituitary and as the name implies stimulates growth and development of follicles within the female ovary. Thus, the administration of exogenous FSH or FSH-like substances (e.g., pregnant mare's serum gonadotropin, PMSG) to cattle has been used for the induction of multiple ovulations and, subsequently, twin or multiple births. These same substances have been used extensively for the induction of superovulation in embryo donor females. Consequently, it was speculated that cows producing twin births naturally from the spontaneous ovulation of multiple ovarian follicles would have higher circulating concentrations …

Immunization Against Inhibin Increases Sperm Production In Young Beef Bulls, Donald D. Lunstra, Terry L. Martin, Gary L. Williams, James J. Ireland

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

The specific biological mechanisms that control pubertal development, testicular growth and onset of sperm production in the beef bull have not been well defined. It is known that two protein hormones (the gonadotropins, LH and FSH) produced by the pituitary stimulate testicular growth, cause an increase in numbers of testicular receptors for LH and FSH, and stimulate production of steroid hormones by the testes. Researchers have shown that the patterns of LH and FSH secretion diverge during the peripubertal period in several species, including the bull. While LH increases during the peripubertal period of development in the bull, FSH exhibits …

Mortality And Cold Tolerance Of Calves With Different Ratios Of Bos Indicus To Bos Taurus Inheritance, Maurie J. Josey, Larry V. Cundiff, Robert M. Koch, Keith E. Gregory, G. Leroy Hahn

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

Results from the Germplasm Evaluation Program (GPE) at the Roman L. Hruska U. S. Meat Animal Research Center (U.S. Meat Animal Research Center) have shown that significant differences exist among cows representing breeds of diverse biological types In such production traits as 200-day weaning wt per cow in the breeding herd. Production of Bos indicus F₁ cross cows (Brahman and Sahiwal sired crosses out of Hereford and Angus dams) was equalled only by F₁ cross cows sired by large size dual purpose breeds (Brown Swiss, Gelbvleh, Simmental, Holstein and Maine Anjou crosses out of Hereford and Angus dams) …

Omasal And Duodenal Nutrient Flow In Steers., Kelly K. Kreikemeier, Gary P. Rupp, Louis J. Perino

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

Feedstuffs are degraded in the rumen, providing energy and nutrients for microbial growth. Volatile fatty acids produced during this process are absorbed and used as an energy source by the animal. The bacteria that are produced and unfermented feed residue flow out of the rumen to the small intestine where further digestion and absorption occurs. Of the total protein flowing to the small intestine, 50 to 90% is microbial protein. It is of high quality, well digested and well used by the animal.

Currently, estimates of the amount of microbial protein synthesized in the rumen vary considerably. We do not …

Puberty Occurs At The Same Testis Size In Both Bos Taurus And Bos Indicus Crossbred Beef Bulls, Donald D. Lunstra, John D. Crouse, Larry V. Cundiff

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

An increasing number of Bos indicus-blood bulls are being used in crossbreeding programs for commercial beef production in the U.S., but there is little information available on pubertal development, sperm production and semen quality for young bulls of this type. Puberty in young Bos taurus bulls has been defined in a variety of ways (e.g., first ability to serve, first sperm production, first ejaculation of motile sperm, etc.), but all of these criteria are costly and labor-intensive to determine. We have shown previously (Lunstra et al., 1978) that, among young Bos taurus beef bulls of various breeds reared in …

Twinning In Cattle, Keith E. Gregory, Sherrill E. Echternkamp, L. Dale Van Vleck, Larry V. Cundiff

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

Rate of reproduction has a major impact on life cycle costs of production of different animal species and upon their competitiveness for different types of production resources. For example, the average beef cow is capable of producing about .7 of her body weight per year in progeny market weight; comparable values are about 8 in pigs, more than 70 in meat chickens and more than 1,000 in catfish. More than 50% of the feed nutrients used by the beef cattle industry of the United States are needed to meet maintenance requirements of reproducing females. The comparable value in meat chickens …

Beef Research Program Progress Report (1993) No. 4 (Part 1): Table Of Contents

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

ROMAN L. HRUSKA U.S. MEAT ANIMAL RESEARCH CENTER, D.B. Laster .... v

General Interest

Beef facilities and management at U.S. Meat Animal Research Center: W. Gordon Hays and Gary S. Ross .... 1

Genetics and Breeding

Cycle V of the germplasm evaluation (GPE) program in beef cattle: Larry V. Cundiff, Keith E. Gregory, and Robert M. Koch .... 3

Contributions of ovum cytoplasm and uterine environment and postnatal environment to maternal effects in beef cattle: Keith E. Gregory, and Ralph R. Maurer .... 6

Germplasm utilization in beef cattle: Keith E. Gregory, Larry V. Cundiff, Robert M. Koch, and Donald …

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 …

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 …

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 …

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 …

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 …

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 …