UT Beef and Forage Center

Health and Pest Management

Prevalence of Tritrichomonas foetus in Tennessee bulls
The prevalence of BT in TN is low. Therefore, current surveillance efforts towards BT control in TN are acceptable. Future efforts should focus on educating TN cattle stakeholders on the importance of optimal specimen collection and handling as well as routine testing for BT before cattle movement. In addition, cattle producers should be reminded of leading risk factors associated with trichomonosis in cattle.

Factors associated with Seroprevalence of Anaplasma marginale in Kentucky cattle
Bovine anaplasmosis (BA) is tick-borne disease of cattle caused by Anaplasma marginale and it remains an economically important disease in the United States (U.S.). We have anecdotal information that Veterinary Feed Directive prescriptions in Kentucky (KY) are written most often for treatment and prevention of BA. However, there are no recent prevalence estimates of this disease in KY. Thus, this study was aimed at determining the seroprevalence of and factors associated with BA in KY.

Past, Present, and Future Contributions and Needs for Veterinary Entomology in the United States and Canada
Trained veterinary entomologists play a vital role in determining how integrated livestock, crop production, and agroecosystems coming online may inadvertently contribute to animal pest populations and how to minimize outbreaks.

Beefing Up Biosecurity: Survey of Ticks Currently Threatening the Tennessee Beef Cattle Industry, and a Proposed Monitoring Strategy for Invasive Ticks
Tick-borne diseases are poised to devastate the North American cattle industry if infected ticks invade the country either by importation of an infested-animal or with natural host migration. Our research objectives were to identify sources for invasive-tick monitoring and use those sources to describe seasonal and regional impacts on infestation prevalence and burden of ticks on beef cattle.

Protective Effect of Anti-SUAM Antibodies on Streptococcus Uberis Mastitis
In the present study, the effect of anti-recombinant Streptococcus uberis adhesion molecule (SUAM) antibodies against S. uberis intramammary infections (IMI) was evaluated using a passive protection model. These findings suggest that anti-rSUAM antibodies interfered with infection of mammary gland by S. uberis which might be through preventing adherence to and internalization into mammary gland cells, thus facilitating clearance of S. uberis, reducing colonization, and causing less IMI.

Grazing and Production Management

Drivers of Grazing Livestock Efficiency: How Physiology, Metabolism, Experience and Adaptability Influence Productivity
To achieve this metabolic adaptability or flexibility, beef cows need to be suited to their environment and have the ability to acclimate to environmental changes. The purpose of this proceedings paper is to identify and describe factors that influence range cow efficiency and ultimately contributes to the sustainability (both from a productivity and economic view point) of range cows in extensive enterprises.

Management of Native Warm-Season Grasses for Beef Cattle and Biomass Production in the Mid-South USA
Native grasses, such as switchgrass, big bluestem, indiangrass, and eastern gamagrass may be capable of providing desirable summer forage for cattle as well as a source of biomass for renewable energy.

Improving Efficiency of Production in Pasture- and Range-Based Beef and Dairy Systems
Continued viability of production systems using pasture- and range-based grazing systems requires more rapid adoption of innovative management practices and selection tools that increase profitability by optimizing grazing management and increasing reproductive performance.

Breeding and Reproduction

Winter Grazing of Stockpiled Native Forages During Heifer Development Delays Body Weight Gain Without Influencing Final Pregnancy Rates
The objective of this study was to test the effects of protein supplementation strategy and different stockpiled forage species on growth, nutritional status, and reproductive performance of yearling beef heifers.

Circulating Beta-hydroxybutyrate Concentration may be a Predictive Measurement for Young Cows that have a Greater Probability to Conceive at a Fixed-time Artificial Insemination
Timing of conception, which has been indicated to be negatively influenced by metabolic dysfunctions, can influence lifetime productivity within the cow herd. Therefore, our objective was to analyze the association of milk production, serum metabolites as an indicator of nutrient status, cow BW and BW change, and calf BW with timing of pregnancy in 183 spring-calving beef cows.

Relationships Among Temperament, Acute and Chronic Cortisol and Testosterone Concentrations, and Breeding Soundness During Performance Testing of Angus Bulls
The aim of this study was to examine relationships among temperament, endocrinology, and reproductive parameters of bulls enrolled in an 84-day performance test. Bulls exhibited physiological evidence of acclimation during the test as indicated by a reduction in hair cortisol concentration. In addition, the ability of the bulls to acclimate while residing at the testing center may have contributed to little differences observed during the breeding soundness examination portion of the performance test.

Does Prepartum Supplemental Feed Impact Beef Cattle Profitability Through Finishing?
Little is known about the impact of a supplemental prepartum feed ration for cows on the profitability of their calves. Therefore, we investigated the impact of animal characteristics and a supplemental prepartum feed program for cows on net returns to finished steers and the probability of a steer grading Choice or higher. Data were collected for 160 Tennessee steers that were finished in a feedlot. The supplemental prepartum feeding program decreased net returns of finished steers. Several animal characteristics were found to influence net returns of finished steers and the probability of a steer grading Choice or higher.

High Milk Production Decreases Cow-Calf Productivity Within a Highly Available Feed Resource Environment
The beef cattle industry tends to focus on selecting production traits with the purpose of maximizing cow-calf performance. One such trait is milking ability, which is considered the primary influence on weaning weight of the calf. Therefore, the objective of this study was to determine the effect of actual milk yield on reproductive performance, circulating blood metabolites, and calf performance in beef cows in the Southeastern US.

Effects of Pre-weaning Feed Supplementation and Total Versus Fenceline Weaning on the Physiology and Performance of Beef Steers
The hypothesis of this experiment was that a 1-week supplementation of the cow-calf pair with the palatable diet would be sufficient time to familiarize the calf to subsequent offering following weaning, thus reducing the acute stress response experienced by the calf following two different methods of separation from its dam. However, the results of the present study suggest that providing a high fiber supplement beginning 7 days prior to weaning may reduce body weight loss and temper the steers' acute stress response when weaned using total separation from their dam

Rumen and Gut Health

Temporal Stability of the Ruminal Bacterial Communities in Beef Steers
Nutritional studies involving ruminants have traditionally relied on relatively short transition or wash-out periods between dietary treatments, typically two to four weeks. However, little is known about adequate adaptation periods required to reach stabilization of the rumen microbiome that could provide more accurate results from nutritional studies in ruminants. This study determined the rumen bacterial communities and rumen environment parameters over ten weeks following transition from a forage-based to concentrate-based diet.

Microbiomes in Ruminant Protein Production and Food Security
The global population is rapidly increasing and will surpass 10 billion people within the next 20 years. As diminishing resources continue to impact agriculture, and with the necessity to feed the world by 2050, the agricultural sector must be able to sustainably and efficiently produce high-quality sources of food that are both attainable to the global population and contribute to healthy, balanced nutrition.This review, therefore, examines the role of microbiomes in ruminants to efficiently and sustainably produce high-quality protein for human consumption to aid in efforts to achieve global food security.

Altering the Gut Microbiome of Cattle: Considerations of Host-Microbiome Interactions for Persistent Microbiome Manipulation
This manuscript reviews contributing factors to the rumen microbiome establishment or re-establishment following rumen microbiome perturbation, as well as host-microbiome interactions that may be responsible for possible host specificity of the rumen microbiome. Understanding and accounting for the variety of factors contributing to rumen microbiome establishment or re-establishment in cattle will ultimately lead to identification of biomarkers of feed efficiency that will result in improved selection criteria, as well as aid to determine methods for persistent microbiome manipulation to optimize production phenotypes.

Effects of Endophyte-infected Tall Fescue Seed and Red Clover Isoflavones on Rumen Microbial Populations and Physiological Parameters of Beef Cattle
In this experiment, feeding isoflavones to Angus cattle did not completely mitigate all symptoms of fescue toxicosis. However, dose–response trials may aid future research to determine if dietary supplementation with isoflavones alleviates fescue toxicosis symptoms and promotes livestock growth and performance.

Effects of Red Clover Isoflavones on Tall Fescue Seed Fermentation and Microbial Populations in vitro
Clovers contain phytoestrogenic compounds known as isoflavones that may be beneficial in reducing physiological limitations with consumption of endophyte-infected tall fescue. This review highlights concerns with endophyte-infected tall fescue as a primary forage base in the southeastern United States and discusses specific physiological and ruminal effects caused by consumption of ergot alkaloids.

Fescue Toxicosis and Its Influence on The Rumen Microbiome: Mitigation of Production Losses Through Clover Isoflavones
Clovers contain phytoestrogenic compounds known as isoflavones that may be beneficial in reducing physiological limitations with consumption of endophyte-infected tall fescue. This review highlights concerns with endophyte-infected tall fescue as a primary forage base in the southeastern United States and discusses specific physiological and ruminal effects caused by consumption of ergot alkaloids.

Effect of Forage Species and Supplement Type on Rumen Kinetics and Serum Metabolites in Growing Beef Heifers Grazing Winter Forage
The objective of this study was to determine the effect of stockpiled forage type and protein supplementation on VFA production, serum metabolites, and BW in yearling beef heifers.These results suggest that a compensatory gain period prior to breeding would be needed for these native warm-season species to be a viable opportunity for growing and developing replacement heifers in the southeastern United States.

Serum Metabolites Associated with Feed Efficiency in Black Angus Steers
Improving feed utilization in cattle is required to reduce input costs, increase production, and ultimately improve sustainability of the beef cattle industry. Characterizing metabolic differences between efficient and nonefficient animals will allow stakeholders to identify more efficient cattle during backgrounding. Four metabolites that differed between low and high residual feed intake have important functions related to nutrient utilization, among other functions, in cattle. This information will allow identification of more efficient steers during backgrounding.

Analysis of the Gut Bacterial Communities in Beef Cattle and Their Association with Feed Intake, Growth, and Efficiency
This review addresses recent research regarding the bacterial communities along the gastrointestinal tract of beef cattle; their association with ADG, ADFI, and feed efficiency; and the potential implications for beef production.

Rumen-protected Arginine Alters Blood Flow Parameters and Luteinizing Hormone Concentration in Cyclic Beef Cows Consuming Toxic Endophyte-infected Tall Fescue Seed
The objective of this study was to determine the effect of rumen-protected arginine on median caudal artery blood flow and LH dynamics in cows fed toxic endophyte-infected tall fescue seed. Supplementing rumen-protected Arg to cows consuming toxic endophyte- infected fescue seed has the potential to increase reproductive performance and peripheral blood flow.

Microbial Community Profiles of the Colon from Steers Differing in Feed Efficiency
Ruminal microbial fermentation plays an essential role in host nutrition, and as a result, the rumen microbiota have been a major focus of research examining bovine feed efficiency. Microbial communities within other sections of the gastrointestinal tract may also be important with regard to feed efficiency, since it is critical to the health and nutrition of the host.

Cecum Microbial Communities From Steers Differing in Feed Efficiency
Apart from the rumen, limited knowledge exists regarding the structure and function of bacterial communities within the gastrointestinal tract
and their association with beef cattle feed efficiency. The study identified cecal microbial associations with feed efficiency, ADG, and ADFI. This study suggests an association of the cecum microbial community with bovine feed efficiency at the 16S level.

Microbial Community Profiles of the Jejunum from Steers Differing in Feed Efficiency
Research regarding the association between the microbial community and host feed efficiency in cattle has primarily focused on the rumen. However, the various microbial populations within the gastrointestinal tract as a whole are critical to the overall well-being of the host and need to be examined when determining the interplay between host and nonhost factors affecting feed efficiency.

Economics and Marketing

Estimating Restaurant Willingness to Pay for Local Beef
This study contributes to understanding local food supply chains and provides a framework for future studies of restaurant willingness to pay for local foods.

Price Determinants of Performance-Tested Bulls over Time
We estimate the values of bull phenotypic traits, performance measurements, and expected progeny differences (EPDs) over time using bull sale data from an auction in Tennessee from 2006 to 2016. Moreover, we determine how a state partial-cost reimbursement program for bulls with certain EPDs affects bull sale price. Purebred seed stock producers in this region should focus on selling large, fastgrowing, mature bulls that produce lighter calves for reduced calving stress. The state cost-share payment did not significantly increase bull prices in most years, meaning this payment was retained by cow-calf producers in most years.

Cow-Calf Producers’ Willingness to Pay for Bulls Resistant to Horn Flies
Horn fly management strategies are labor intensive and can become ineffective due to the horn fly’s ability to develop insecticide resistance. Research indicates that for some cattle herds, genetically similar animals consistently have fewer flies suggesting those animals are horn fly resistant (HFR) and that the trait is heritable; however, it is currently unknown if cattle producers value this trait. Tennessee and Texas cow-calf producers were surveyed to estimate their willingness to pay for HFR bulls and to identify the factors affecting their decision to adopt a HFR bull in their herds.

Is the Natural Label Misleading? Examining Consumer Preferences for Natural Beef
A petition to the USDA claims that natural labeling misleads consumers. We investigate this claim using an online choice experiment to determine consumer willingness to pay for steak labeled as natural. Half of the sample was provided with the definition of natural, while half was not. The absence of the definition resulted in consumers placing a premium on “natural” steak, while those provided with the definition were not willing to pay a premium. Similarly, participants who consider themselves familiar with the natural definition did not place a premium on “natural” steak. Results indicate that consumers may misinterpret the natural label.

Beef Cattle Farmers’ Marketing Preferences For Selling Local Beef
To meet the growing consumer demand for local foods, there has been increased interest by farmers to produce local foods. One facet of meeting this demand is how farmers may prefer to market their locally produced products. In this study, we examine beef cattle farmers’ marketing preferences for selling a Tennessee Certified Beef product.

Consumer Willingness to Pay For Tennessee Certified Beef
A choice experiment was administered to Tennessee consumers to determine their willingness to pay for Tennessee Certified Beef (TCB) and other attributes such as labels indicating producer participation in AMBP and BQA. This research found that producers would gain premiums for their beef by conveying to consumers that they are BQA and AMBP certified.

Tennessee Beef Producers' Willingness to Participate in a State Branded Beef Program
Tennessee cattle producer willingness to participate in a hypothetical Tennessee Branded Beef Program (TBBP) was examined using 2016 survey data. This research found that 67% of the Tennessee cattle producers surveyed were willing to participate in a TBBP given it was profitable, and, on average, among those willing to participate, each producer was willing to supply nearly 33,000 pounds of beef on average to a TBBP annually.

Replacement Beef Cow Valuation under Data Availability Constraints
Economists are often tasked with estimating the benefits or costs associated with livestock production losses; however, lack of available data or absence of consistent reporting can reduce the accuracy of these valuations.

Beef Cattle Retained Ownership and Profitability in Tennessee
The effect of animal characteristics and placement decisions on retained ownership profitability of Tennessee cattle from 2005 to 2015 was determined using a mixed model regression. Regression results indicate that placement weight, placement season, days on feed, animal health, and animal sex affect retained ownership profitability. Simulation results indicate that winter placement of cattle in feedlots had the highest expected retained ownership profits. Results provide risk-averse producers information regarding the profitability of retained ownership.

Probability of Receiving an Indemnity Payment from Feeder Cattle Livestock Risk Protection Insurance
Livestock risk protection (LRP) insurance is a price risk management tool available to cattle producers; however, producers have been hesitant to adopt LRP. The objective of the study was to determine the monthly feeder cattle LRP contract coverage level and length maximizing the probability of the LRP net price being greater than the CME Feeder Cattle Index (CME FCI) price. The CME FCI prices were higher than the LRP net price for the majority of the contract lengths and coverage levels. Several coverage lengths and levels provided similar price protection, and there was no consistent preferred coverage length and level.

Profitability of Beef and Biomass Production from Native Warm-Season Grasses in Tennessee
Native warm-season grasses (NWSGs) have demonstrated potential to reduce summer forage variability, and furthermore, there has been growing interest in the use of NWSGs as lignocellulosic biomass crops. The objective of this research was to determine if there was a difference in net returns for full-season summer grazing beef steers on three NWSGs.

Bull and Steer Management

Relationships Among Temperament Behavior, and Growth During Performance Testing of Bulls
Excitable cattle are dangerous to personnel and have reduced individual performance. The aim of this study was to 1) identify objective criteria for evaluating bull temperament and 2) examine relationships among temperament, behavior, and performance of bulls during an 84-d performance test.