Animal Sciences Commons^™

Demasculinization Of Beef Bulls By Lh Immunization, Bruce D. Schanbacher

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

Intact bull calves grow more rapidly in the feedlot than do their castrate counterparts but are generally less acceptable to the packer because of excess masculinity and insufficient intramuscular and external fat for postmortem handling and storage. Steers, on the other hand, are less efficient and yield less lean meat than bulls. Therefore, it was envisaged that reducing the masculinity of bulls by a noninvasive, nonsurgical procedure might yield a more suitable market animal.

Effect Of Season And Relocation On Reproductive Competence In Brahman And Hereford Bulls, Robert W. Godfrey, Ronald D. Randel, Charles R. Long, Donald D. Lunstra, Thomas G. Jenkins, James Berardinelli

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

Careful selection of a breed or breeds and emphasis upon selection pressure within a breed can increase productivity of a beef cattle herd. Furthermore, productivity within a herd may be effectively increased by utilizing crossbreeding programs. Crossing genetically diverse breeds permits combination of important traits and taking advantage of hybrid vigor. Many crossbreeding programs currently in use involve crosses between Bos indicus and Bos taurus cattle. One of the more commonly used Bos indicus breeds is the American Brahman. Use of the American Brahman in crossbreeding programs throughout the U.S. would increase demand for bulls of this breed.

Brahman cattle …

Effects Of Dietary Energy Density On Carcass Composition And Beef Palatability Characteristics, Gary L. Bennett

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

Currently there is increased emphasis on production of lean beef with desirable palatability characteristics. Changes in both the type of animal produced and the feeding and management of these animals may be needed to efficiently produce this product. One change in feeding that could be made is the energy density of the feed, measured as megacalories of metabolizable energy per pound (Mcal ME/lb). At low energy densities, the amount of feed that can be consumed limits the animal's intake of metabolizable energy.

Over the past two decades, several experiments at U.S. Meat Animal Research Center have examined a number of …

Follicle And Oocyte Relationships During Superovulation In The Heifer, Thomas H. Wise, Ralph R. Maurer

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

As the female cow matures, the majority of her follicles become atretic and are lost as a store house of the female gamete (oocyte). Emphasis on in vitro fertilization to maximize the utilization of superior animals for transplant of frozen embryos is considerably limited by the number of viable mature oocytes that can be collected. Understanding the biochemical environment required to produce maximum numbers of mature, fertilizable oocytes is a prime requirement to utilize this technology in increasing meat animal production and efficiency.

The goal of these studies was to characterize the endocrine and biochemical events associated with follicle and …

Breeding For Lean Beef (Germ Plasm Evaluation Program), Larry V. Cundiff, Michael E. Dikeman, R. M. Koch, John D. Crouse, Keith E. Gregory

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

Historically, when steers were finished on pasture, ability to finish at a young age was desirable, particularly when market requirements for fatness were great. However, ability to fatten became a handicap as we shifted to increased use of concentrate feeds in diets of growing-finishing cattle. Consequently, yield grades were added to the USDA grading system to reflect variation in carcass value associated with differences in yield of retail product. Recently, consumer pressure to reduce caloric and fat content of beef and other red meats has intensified because coronary heart disease is believed to be associated with elevated blood-cholesterol levels. Cholesterol …

Heterosis, Breed Maternal, And Breed Direct Effects In Red Poll And Hereford Cattle, Keith E. Gregory, Delwyn D. Dearborn, Donald D. Lunstra, Larry V. Cundiff, Robert M. Koch

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

Breed differences, heterosis, and reciprocal cross differences from beef cattle crossbreeding experiments have been summarized in prior reports from U.S. Meat Animal Research Center and reports from other research stations.

However, there have been only limited reports to characterize the Red Poll breed relative to other breeds. This report summarizes results from an experiment where reciprocal crosses and straightbreds were produced to estimate heterosis, breed maternal effects, and breed effects for growth rate of the Red Poll and Hereford breeds.

Individual Heterosis Effects On Mature Size And Maternal Heterosis Effects On Preweaing Traits And Postweaning Growth And Carcass Traits, Keith E. Gregory, Delwyn D. Dearborn, Larry V. Cundiff, Robert M. Koch

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

The Brown Swiss, Red Poll, Hereford, and Angus breeds and their 12 reciprocal crosses from a four.breed diallel crossing experiment were evaluated for production and carcass characters. Estimates of average heterosis and breed maternal and additive direct effects were reported earlier for preweaning traits, growth rate and puberty in females, growth traits of steers, and carcass traits of steers. This report provides results from the second phase of this experiment for maternal performance data on the females, including estimates of heterosis and breed maternal and additive direct effects on cow size and on preweaning traits, postweaning growth, and carcass traits …

Effect Of Subcutaneous Fat Removal On Beef Tenderness, Mohammad Koohmaraie, Steven C. Seideman, John D. Crouse

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

It is now widely recognized that consumers do not accept meat with excessive quantities of fat. To make cuts of meat acceptable to the consumer, packers and retailers are forced to trim much of the subcutaneous fat. If this consumer demand persists, the meat industry will be forced to change its production system to produce leaner cattle.

Subcutaneous fat cover is thought to act as an insulator, retarding rapid temperature decline and consequently preventing cold-induced toughness. Cold-induced toughening is a phenomenon observed when prerigor excised muscles are exposed to cold ( < 50° F) temperatures. However, there is no conclusive evidence that cold-induced toughening actually happens under current meat industry practices of slaughtering and carcass handling. The objectives of these experiments were to examine the effect of the removal of subcutaneous fat and high temperature conditioning on beef tenderness. High temperature conditioning (HTC) - storage of carcasses at high temperatures (e.g. 78° F) for 3 to 6 hr after slaughter - was included to attempt prevention of cold-induced toughness in defatted carcasses.

Inheritance Of Active And Passive Immunity In Beef Calves, Noelle E. Muggli, Bill D. Hohenboken, Larry V. Cundiff, Don E. Mattson

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

Disease is caused by successful invasion of pathogenic organisms (e.g., viruses, bacteria, parasites). The immune system is responsible for the protection of an individual against these invasions. This system is complex, with interconnective parts composed of many stimulators, inhibitors, effectors, and consequences. Immunity that is dependent upon antibodies or immunoglobulins can be either active or passive in origin. In active immunity, the body produces protecting antibodies in response to a naturally occurring infection or to vaccination against a pathogenic organism. Vaccination will prime the animal's immune system for a faster and more effective response to later infections. In passive immunity, …

Inheritance Of Vertical Fiber Hide Defect, Larry V. Cundiff, Matthew P. Dahms, Mary V. Hannigan, Alfred L. Everett, Peter E. Buechler

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

Cattle leather with vertical fiber hide defect (VFHD) breaks when stretched and, consequently, is not suitable for production of shoe uppers. Typical tensile strength of VFHD leather is only 50% of normal leather. VFHD is caused by a structural defect of collagen fiber orientation in the corium layer of cattle hides. The defect was first described by Amos, an Australian research chemist, in 1958. Economic losses to the leather industry were estimated to exceed $10 million in 1973.The cost can be high because the defect is often not detected until after the expense of tanning has been incurred. The defect …

Microbial Decontamination And Weight Of Carcass Beef As Affected By Automated Washing Pressure And Length Of Time Of Spray, John D. Crouse, Maynard E. Anderson, H. Donald Naumann

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

Carcass beef has traditionally been washed by hand to remove foreign material such as hair, soil particles, and microbiological organisms that have contaminated the surfaces. These carcasses are inspected by the Food Safety Inspection Service (FSIS)to detect defects related to carcass cleanliness. Recent research and development of technology have emphasized automated machine washing.

At pressures above that normally used, it is conceivable that water could penetrate tissue surfaces and be absorbed by the carcasses. Also, longer wash periods may enhance water uptake by carcasses. According to the ASH RAE Handbook and Product Directory, the average shrinkage of carcass beef using …

More Lean, Less Fat With Clenbuterol, Joan H. Eisemann, Gerald B. Huntington, Calvin L. Ferrell

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

There is too much fat on beef carcasses today. Research in beef cattle production is directed towards solving this problem by maximizing partitioning of dietary nutrients to lean muscle growth and minimizing deposition of carcass fat. Partitioning agents called β - adrenergic agonists are able to cause this type of nutrient partitioning. Earlier work showed two of these compounds, clenbuterol and cimaterol, can be fed and are effective in many species including pigs, sheep, and cattle. At levels that did not depress gain, clenbuterol feeding increased protein content of the 9th to 11th rib section by 13% and decreased fat …

Influence Of Genotype And Maternal Environment On Growth Hormone And Prolactin Secretion In Cattle, John Klindt, Ralph R. Maurer

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

The phenotype of an individual is the manifestation of that individual's genotype, environment, and the interaction of that genotype and environment. The genotype is attributable to nuclear genetic material equally contributed by the sire and the dam. The in utero environment and(or) the genotype of the dam (maternal effects) have long been known to have an influence on fetal and postnatal development. These effects were documented by Walton and Hammond (1938), who described the growth of Shetland pony-Shire horse reciprocal crosses. The physiology of the individual (e.g., enzyme activities, endocrine secretion and function) is the phenotypic expression of that individual's …

Influence Of Biological Types On Energy Requirements, Calvin L. Ferrell, Thomas G. Jenkins

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

Since the introduction of new germ plasm resources into the U.S. beginning in the early 1960's, the influence of biological types on various aspects of beef production have been evaluated extensively. Traits studied include preweaning calf performance, postweaning growth and feed efficiency, carcass characteristics, puberty and other reproductive characteristics, and milk production, to name a few. In general, however, most of the research efforts have concentrated on the areas involving the growing animal and/or its carcass characteristics. That is, output characteristics of the various biological types of cattle have been of primary interest to researchers. Much less effort has been …

The Effect Of Sex And Age On The Textural Properties And Mineral Content Of Beef Steaks, Steven C. Seideman, H. Russell Cross, John D. Crouse

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

Extensive research has been conducted on objectively assessing the palatability characteristics, particularly tenderness, of carcass meat. A patent (#4,009,390)by Satterlee et al. (1977) claimed that the ratio of iron (Fe) to zinc (Zn) in beef was highly correlated to its tenderness and that it is also easy to calculate a Fe/Zn ratio accurately with spectrophotometric methods.

An increase in the crosslinking between strands of collagen decreases the solubility of collagen, and also decreases the tenderness of the meat. High moist heat is required to improve tenderness of meat with extensive crosslinking of collagen. Increases in crosslinking of collagen is generally …

The Effects Of Rate Of Change In Body Weight On Tissue Development And Meat Quality Of Youthful Bulls, John D. Crouse, Chris R. Calkins, Steven C. Seideman

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

Growth and development of meat-producing animals involves a complex integrated system of changes in the structure and mass of body tissues. Researchers have observed and documented that meat animal growth and development may be altered through the diet or alteration of the sex condition. Most significant alterations are in rates of deposition of protein, fat, and connective tissue, as well as the palatability of the cooked meat. Changes in wt of cattle beyond 14 mo of age have been largely associated with the fat deposition in the body. Studies have shown that youthful bulls have advantages in performance of growth …

Twinning In Cattle, Keith E. Gregory, Sherrill E. Echternkamp, Gordon E. Dickerson, Larry V. Cundiff, Robert M. Koch

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

Why an interest in twinning in cattle?

. More than one-half of the feed units used by the national beef herd are needed to meet maintenance requirements of the reproducing female population.

. The beef cow is capable of producing about .7 of her body weight per year in progeny market weight.

. The sow is capable of producing more than 8 times her body weight per year in progeny market weight.

. The meat type hen is capable of producing more than 70 times her body weight per year in progeny market weight.

. The channel catfish female is …

Yield Grades And Cutability Of Carcass Beef With And Without Kidney And Pelvic Fat, John D. Crouse, Robert M. Koch, Michael E. Dikeman

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

The Agricultural Marketing Service proposed a revision to the yield grade standards to provide the industry with an option regarding the retention or removal of kidney and pelvic fat (KPF) depending on market requirements. The proposal was subsequently withdrawn. The present yield grades are determined by consideration of external fat thickness, hot carcass wt, ribeye area, and estimated percent KPF. The proposed revision would eliminate consideration of KPF in the determination of yield grades.

The present study used 2,550 observations of retail yield of carcasses obtained from steers with genetically diverse growth rates and fattening characteristics to: 1) examine by …

Relationship Of Visceral Components Of Mature Cows As Related To Lactation Potential And Possible Effects On Productivity, Thomas G. Jenkins, Calvin L. Ferrell, Larry V. Cundiff

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

Production output characteristics for cows of breeds or breed crosses varying in genetic potential for growth rate, mature size, and lactation have been previously reported. These differences among breeds were reported for characteristics associated with output potential (e.g., gestation length, calving difficulty, calf crop weaned, and for wt at birth, weaning, and at puberty). We have reported differences among nonpregnant, nonlactating mature cows of breed crosses varying in genetic potential for mature size and lactation yield for dry matter required for weight stasis and metabolizable energy (ME) required for zero body energy change. We have reported significant differences among various …

Use Of Mechanical Tenderization To Increase The Tenderness Of Bull Beef, Steven C. Seideman, H. Russell Cross, John D. Crouse

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

Numerous studies have shown that meat from bulls is less tender than meat from steers of comparable age and feeding regimen. Collagen crosslinking has been reported to be more extensive in bulls than in steers of similar age and has been implicated as a potential cause of toughness in meat from bulls.

Several studies have shown that blade tenderization improved the tenderness of beef and decreased the amount of sensory panel-detectable connective tissue. Also, it has been reported that blade tenderization of bull muscles resulted in steaks which required less time to cook, had decreased amounts of detectable connective tissue, …

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 …

Bison, Hereford, And Brahman Growth And Carcass Characteristics, Robert M. Koch, John D. Crouse, Steven C. Seideman

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

Bison, Hereford, and Brahman represent three species of the bovine family that evolved under different environmental conditions. There has been much interest in these species and hybrids among them to find animal types that are better adapted to the climatic conditions of the U.S. northern temperate zones down to the subtropical areas. There has been considerable research on growth and carcass characteristics of crosses among British, European, and Brahman cattle types, such as studies at U.S. Meat Animal Research Center. However, there is little experimental documentation of the growth and carcass merit of Bison or their crosses. The three species …

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 …

Beef Research Program Progress Report No. 3 (1988): Table Of Contents

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

ROMAN L. HRUSKA U.S. MEAT ANIMAL RESEARCH CENTER,Robert R. Oltjen .... iv

General Interest

Beef facilities and management: Margaret S. McAlhany, W. Gordon Hays, and Gary S. Ross .... 1

Genetics and Breeding

Germ Plasm Evaluation in cattle: Larry V. Cundiff, Robert M. Koch, and Keith E. Gregory .... 3

Breeding for lean beef (Germ Plasm Evaluation Program): Larry V. Cundiff, Michael E. Dikeman, Robert M. Koch, John D. Crouse, and Keith E. Gregory .... 5

Germ Plasm Utilization in beef cattle: Keith E. Gregory, Larry V. Cundiff, and Robert M. Koch .... 9

Individual heterosis effects on mature size …

Animal And Forage Response To Short-Duration Rotational Grazing, Hans-Joachim G. Jung, Richard W. Rice, Ling-Jung Koong

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

It has recently been suggested that the use of a short-duration rotational grazing (SDG) system can significantly increase total beef production on rangelands. The periodic intense grazing pressure of the SDG system is assumed to retard maturation of the forage and stimulate forage growth. This combination of immature, high quality forage and greater total forage production should allow higher stocking rates and/or improved animal performance. Such a system may be of greater utility with improved pastures planted to forages possessing a greater genetic potential for growth. This study was designed to determine the animal and forage responses to SDG on …

Causes And Influences Of Repeat Breeding In Beef Cattle, Ralph R. Maurer, Sherrill E. Echternkamp

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

Repeat-breeding females were classified as those females nonpregnant after two consecutive breeding seasons of 45 to 60 days' duration. Females were either naturally mated or artificially inseminated and exposed to clean-up bulls. Each year, approximately 7,000 beef females (6,803 to 7,374) at the Research Center were bred by either artificial insemination (approximately 2,000 females) and/or exposure to single or multiple sires in two breeding periods of 45 to 60 days' duration. Breeding periods were either May 15 to July 15 or November 1 to December 31 during 1979 through 1982. During the four years, 165 heifers and 241 cows (clinically …

Effects Of Sex Condition And Diet On Growth And Carcass Characteristics, John D. Crouse, Calvin L. Ferrell, Larry V. Cundiff

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

Studies quantifying the differences between bulls and steers have generally shown that bulls gain more rapidly and more efficiently than steers and produce leaner carcasses. The average of these studies gave bulls a 17 percent advantage in average daily gain and a 13 percent advantage in converting feed to liveweight gain. Feed efficiencies reported in these studies were determined on animals fed to similar ages or weights. The effects of sex condition on feed efficiency of animals fed to a similar fat composition or marbling endpoint needs to be examined.

Effects Of Sex Condition, Diet, And Electrical Stimulation On The Collagen And Palatability Of Two Muscles, John D. Crouse, H. Russell Cross, Steven C. Seideman

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

Meat obtained from intact males has been observed to be less tender than meat obtained from castrated males. Studies have shown that meat from intact males was one sensory panel score less tender than comparable meat from castrated males when animals were fed to about the same age. Reported studies comparing palatability characteristics of meat from bulls and steers have been made on animals fed to similar ages or weights; consequently, compared sex conditions have been confounded with carcass compositional differences.

The objectives of the present study were to determine the effects of sex condition and dietary energy density on …

Embryo Transfer In Beef Cattle Research, Ralph R. Maurer, Acacia A. Alcivar

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

Embryo transfer techniques have been utilized to increase the number of desirable animals (e.g., exotic breeds) or to study factors influencing embryonic development. Embryo transfer is predominantly used at the Research Center as a research tool to answer questions about embryonic development and maternal influence on subsequent growth of the newbom calf.

Embryo transfer utilizes the techniques of 1)superovulation; 2)surgical or nonsurgical embryo collection and transfer; and 3)handling the embryo between collection and transfer. Therefore follicular development as well as fertilization rates play important roles in the production of viable embryos. A large variation in response to the superovulatory procedure …