At The University of Tennessee Institute of Agriculture projects related to beef cattle with management practices, genetics, nutrition, breeding, economics, and reproduction are presented here to highlight the accomplishments of our researchers.
Publications and Reports
Rumen Biogeographical Regions and Their Impact on Microbial and Metabolome Variation
Authors: M. P. Soltis, M. T. Henniger, A. M. Egert-McLean, B. H. Voy, S. E. Moorey, L. G. Schnieder, E. A. Shepherd, C. Christopher, S. R. Campagna, J. S. Smith, and P. Y. Mulon
The rumen microbiome is a complex microbial network critical to the health and nutrition of its host, due to their inherent ability to convert low-quality feedstuffs into energy. In rumen microbiome studies, samples from the ventral sac are most often collected because of the ease of access and repeatability. However, anatomical musculature demarcates the rumen into five sacs (biogeographical regions), which may support distinct microbial communities. The distinction among the microbes may generate functional variation among the rumen microbiome, thus, specialized tasks within different sacs. The objective of this study was to determine the rumen liquid metabolome and epimural, planktonic, and fiber-adherent bacterial communities among each rumen biogeographical region.
Evaluation of Two Beef Cow Fixed-time AI Protocols that Utilize Presynchronization
Authors: Jaclyn N. Ketchum, Lacey K. Quail, Kaitlin M. Epperson, Chloey P. Guy, Jerica J.J. Rich, Saulo Menegatti Zoca, Adalaide C. Kline, and Taylor N. Andrews, Julie A. Walker, Pedro Levy Piza Fontes, Sandy K. Johnson, Megan P.T. Owen, Douglas Eborn, Kelsey M. Harvey, Adam F. Summers, and George A. Perry
Effectiveness of presynchronization method depends on a cow’s physiological status at the beginning of the synchronization protocol. Although the 7&7 protocol increased estrus response compared with the PG6d, there was no difference in pregnancy success, thus utilization of both forms of presynchronization resulted in acceptable pregnancy rates.
Importance of the Female Reproductive Tract Microbiome and its Relationship with the Uterine Environment for Health and Productivity in Cattle: A Review
Authors: T. B. Ault-Seay, S. E. Moorey, D. J. Mathew, F. N. Schrick, K. G. Pohler, K. J. McLean, and P. R. Myer
Although the presence of a reproductive tract microbiome has become widely accepted, the existence of a placental microbiome and in utero colonization of the fetus is still a popular debate due to conflicting study results. Currently, researchers are evaluating methods to manipulate the reproductive bacterial communities, such as diet changes and utilizing probiotics, to improve reproductive outcomes. The following review discusses the current understanding of the reproductive tract microbiome, how it differs between humans and cattle, and its relationship with the uterine environment.
Rumen Biogeographical Regions and Microbiome Variation. Microorganisms
Authors: M. P. Soltis, S. E. Moorey, A. M. Egert-McLean, B. H. Voy, E. A. Shepherd, and P. R. Myer
The rumen microbiome is a complex microbial network critical to the health and nutrition of its host, due to their inherent ability to convert low-quality feedstuffs into energy. In rumen microbiome studies, samples from the ventral sac are most often collected because of the ease of access and repeatability. However, anatomical musculature demarcates the rumen into five sacs biogeographical regions), which may support distinct microbial communities. The distinction among the microbes may generate functional variation among the rumen microbiome, thus, specialized tasks within different sacs. The objective of this study was to determine the rumen liquid metabolome and epimural, planktonic, and fiber-adherent bacterial communities among each rumen biogeographical region.
Blood Parameters Associated with Residual Feed Intake in Beef Heifers
Authors: B. A. Clemmons, T. B. Ault-Seay, M. T. Henniger, M. G. Martin, P. Y. Mulon, D. E. Anderson, B. H. Voy, K. J. McLean, and P. R. Myer
Blood chemistry may provide indicators to greater feed efficient cattle. As a side objective to previous research, 17 Angus heifers approximately two years old underwent a feed efficiency trial to determine residual feed intake (RFI) and identify variation in blood chemistry in beef cattle divergent in feed efficiency. The greater abundance of BUN in high-RFI heifers may indicate inefficient utilization of protein or mobilization of tissue protein for nonprotein use. Greater blood glucose concentrations in low-RFI heifers may indicate greater utilization of energy precursors, such as volatile fatty acids, or metabolites. These data suggest there are readily measurable indicators of physiological variation in nutrient utilization; however, this warrants additional studies to explore. The Impacts of Supplemental Protein during Development on Amino Acid Concentrations in the Uterus and Pregnancy Outcomes of Angus Heifers
Authors: Kiernan J. Brandt, Taylor B. Ault-Seay, Rebecca R. Payton, Liesel G. Schneider, J. Lannett Edwards, Phillip R. Myer, Justin D. Rhinehart, and Kyle J. McLean
Replacement heifer development is a critical component in beef production. The identification of the ideal uterine environment will greatly benefit reproductive efficiency. Additionally, the elucidation of how diet can influence this environment could alter management strategies. Supplemental protein did not greatly affect the uterine environment as it pertained to amino acid concentrations. However, uterine amino acid concentrations did change throughout development, and protein supplementation can influence uterine luminal fluid composition on d 14 post-insemination, which may affect conception rates.
Beta-Adrenergic Agonists, Dietary Protein, and Rumen Bacterial Community Interactions in Beef Cattle: A Review
Authors: Alison P. Pfau, Elizabeth A. Shepherd , M. Gabbi Martin, Sophia Ascolese, Katie M. Mason, Amanda M. Egert-McLean, Brynn H. Voy, and Phillip R. Myer
To address common feed and management practices and their impact on the rumen microbial community, this review addresses the interactions among beta-adrenergic agonists, protein level and source, and the ruminal microbiome. Advancing our understanding of feed and management practices and their association with the rumen microbiome will help to sustainably improve beef cattle performance.
Livestock Risk Protection Subsidies Changes on Producer Premiums
Authors: Christopher N. Boyer and Andrew P. Griffith
Livestock Risk Protection (LRP) insurance can reduce losses from price declines for cattle producers, but LRP adoptions has been limited. In 2019 and 2020, LRP subsidies were increased to lower the cost, but it is unclear how much these changes lowered the cost. The objective of this research was to estimate the impact of the subsidy increase on the cost of LRP for feeder and fed cattle by month and for various insurance period lengths and levels. Results show policy implications from the subsidy increases and will be informative to producers when exploring the cost of LRP. This study extends the literature by estimating the reduction in subsidy costs while considering total premiums changed.
Beef and Pork Processing Plant Labor Costs
Authors: Christopher N. Boyer, Dayton M. Lambert, Charles C. Martinez, and Joshua G. Maples
Federal and state legislators recently enacted policies to fund new and renovated small and local meat processors expansion with the aim of increasing the meat‐processing sector’s resiliency. Wages must be competitive to attract employees for these new and renovated plants to be competitive. Thus, if smaller facilities increase the sector’s resiliency, then it will likely come at a cost in terms of higher wage bills.
Cow-Calf Producer Preferences for Bull Genomic Enhanced Expected Progeny Differences
Authors: K.V. Smith, Karen L. DeLong, Andrew P. Griffith, Christopher N. Boyer, Charley Martinez, and Kimberley L. Jensen
Genomic enhanced expected progeny differences (GE-EPDs) combine expected progeny differences (EPDs) with DNA information to improve EPD accuracy values. In 2020, Tennessee cattle producers completed a between-subjects choice experiment for bulls marketed with either EPDs or GE-EPDs. Panel Tobit regression results indicate that, on average across all considered EPDs, producers were not willing to pay significantly more for GE-EPDs than EPDs. However, producers were willing to pay more for the calving ease direct EPD if it was genomic enhanced. This is the first known study to evaluate producers’ value of improved accuracy scores associated with GE-EPDs.
Relationship of Field and in vitro Fertility of Dairy Bulls with Sperm Parameters, Including DAG1 and SERPINA5 Proteins
Authors: Saulo Menegatti Zoca, Julie A. Walker, Adalaide C. Kline, Taylor N. Andrews, Jerica J. J. Rich, Kaitlin M. Epperson, Jessica Nora Drum, M. Sofia Ortega, Robert A. Cushman, and George A. Perry
Sperm interacts with the female reproductive tract and oocyte through proteins, and these cell-to-cell interactions may play a role in sperm fertility. For consideration of a protein as a potential marker of fertility, there must be variability expressed among animals. The proteins dystroglycan (DAG1) and plasma serine protease inhibitor (SERPINA5) have been reported to play a role in cell-to-cell interactions, Thus, when evaluated by immunofluorescent microscopy, DAG1 and SERPINA5 concentrations are variable and are not good fertility markers for bull sperm.
Bull Field Fertility Differences can be Estimated with in vitro Sperm Capacitation and Flow Cytometry
Authors: Saulo Menegatti Zoca, Thomas W. Geary, Abigail L. Zezeski, Karl C. Kerns, Joseph C. Dalton, Bo R. Harstine, Matthew D. Utt, Robert A. Cushman, Julie A. Walke, and George A. Perry
This study evaluated whether post in vitro capacitation changes in sperm could be used to estimate field fertility differences between bulls. In summary, incubation of sperm in CM and flow cytometry analyses for viability, zinc signatures 2 and 1+2, and dead CD9+ seems promising to estimate in vivo fertility differences amongst bulls. The inclusion of viability, a zinc signature, or a CD9 protein assay in quality control measurements may have the potential to better predict bull fertility; however, a larger number of bulls with known fertility and different breeds need to be evaluated to validate these results.
Subsidy Rate Changes on Livestock Risk Protection for Feeder Cattle
Authors: Christopher N. Boyer and Andrew P. Griffith
We determine the impact the 2020 Livestock Risk Protection (LRP) subsidy rate structure has on the probability of LRP having a higher price than the actual cash price. Monthly logit models were estimated to determine these probabilities with the previous and new subsidy rate. The preferred coverage lengths and levels vary across months as does LRP’s effectiveness in managing price risk. The new subsidy structure increases LRP’s effectiveness as a risk management tool in some months. Results show the LRP contract that provides the best protection by sell month and the impact of the new subsidy rates.
Optimal Stocker Production Strategies for Spring and Fall Calving Cow Herd
Authors: Cora Key, Christopher N. Boyer, Charles C. Martinez, and Katie M. Mason
We determine optimal stocker strategies based on calving season, herd size, and the number of days of retention before marketing weaned calves. We estimate a hedonic pricing model for feeder cattle and incorporate this into a simulation model that considers the variability of cattle prices and feed costs. The profit and utility-maximizing decision for fall calving herd would be to retain weaned calves for 150-day postweaning. The producer marketing spring-born calves would prefer to sell these calves at weaning. The results are being utilized by extension to aid cattle producers in reducing their feed costs and increasing their profits.
Predicting Seedstock Bull Prices: Does Information Matter?
Authors: Seth Ingram, Charles C. Martinez, Christopher N. Boyer, Samir Huseynov, Troy N. Rowan, Mykel R. Taylor, and Elmin Alizada
We investigate the role of optimism bias in bull price expectations using incentivized lab-in-the-field experiments with Alabama and Tennessee cattle producers. We develop bull price prediction tasks and reward accurate predictions. We find that the EPD information provision prevents optimism bias from contaminating price expectations in the whole sample. However, we also document that, unlike buyers, sellers are prone to unrealistic optimistic expectations, and our results reveal that optimism bias can be moderated by the type of expected progeny difference information utilized, breed characteristics, and regional differences in cattle operations. We contribute to the literature by documenting the role of behavioral biases.
The Effects of Nutritional Level and Body Condition Score on Cytokines in Seminal Plasma of Beef Bulls
Authors: Taylor D. Harrison, Elizabeth M. Chaney, Kiernan J. Brandt, Taylor B. Ault-Seay, Rebecca R. Payton, Liesel G. Schneider, Lew G. Strickland, F. Neal Schrick, and Kyle J. McLean
High quality semen is essential for reproductive efficiency. Nutrition and environmental factors impact the ejaculate components, like cytokines, that are essential for pregnancy establishment. We hypothesized that differing nutritional periods and body condition scores would affect seminal plasma cytokine concentrations of bulls. In conclusion, cytokines and chemokines fluctuated between the nutritional periods, potentially in response to nutritional stress.
Effects of a Moderate or Aggressive Implant Strategy on the Rumen Microbiome and Metabolome in Steers
Authors: M. T. Henniger, J. E. Wells, K. E. Hales, A. K. Lindholm-Perry, H. C. Freetly, L. A. Kuehn, L. G. Schneider, K. J. McLean, S. R. Campagna, C. J. Christopher, and P. R. Myer
The effects of growth-promoting implants have been well-defined for their ability to impact growth performance in beef cattle. Production-relevant microbes and microbiomes in the rumen have also been associated with growth traits. However, the role of implants on the rumen microbiome has not been determined. The objective of this study was to determine if different doses of implant hormones cause gain-associated ruminal microbial community changes. Two metabolites, N-acetyllysine and N-acetylornithine, were found in greater abundance in the moderate implant strategy. Understanding associations between the rumen microbiome and implant strategies may allow improvement of growth efficiency in beef cattle.
Ruminal Bacterial Communities and Metabolome Variation in Beef Heifers Divergent in Feed Efficiency
Authors: B. A. Clemmons, P. Y. Mulon, D. E. Anderson, T. B. Ault-Seay, M. T. Henniger, L. G. Schneider, M. Staton, B. H. Voy, D. R. Donohoe, S. R. Campagna, and K. J. McLean
This study determined potential microbial and metabolic biomarkers of feed efficiency in Angus heifers. Seventeen ruminal cannulated Angus heifers underwent a 70-day feed efficiency trial. Residual feed intake was used to determine high and low feed efficient heifers. These data suggest variation in the availability of nutrients, primarily amino acids, as well as a relationship among microbiota, metabolome, and host feed efficiency phenotypes in heifers.
Feeding an Acetate-based Oral Electrolyte Reduces the ex vivo Escherichia coli Growth Potential in the Abomasum of Calves Fed Oral Electrolytes Alone or 30 Minutes Following a Milk Feeding Compared with Feeding a Bicarbonate-based Oral Electrolyte
Authors: B. A. Kasl, V. S. Machado, M. T. Henniger, P. R. Myer, and M. A. Ballou
Oral electrolyte solutions (OES) are a common, on farm therapy to reestablish hydration and electrolyte balances in scouring and stressed calves. The objectives were to determine the effects of OES alkalinizing agent and the presence of a milk replacer feeding before OES administration on the abomasal environment in healthy Holstein calves. Preweaning calves are highly susceptible to dehydration given their susceptibility to scouring gastrointestinal diseases. Oral electrolyte solutions represent an effective, economical on-farm therapy to maintain or restore hydration and correct metabolic acidemia.
Invited Review: Genetic Decision Tools for Increasing Cow Efficiency and Sustainability in Forage-based Beef Systems
Author: Troy N. Rowan
The beef industry is experiencing pressure to increase the efficiency and sustainability of forage-based cow-calf production. Dozens of traits affect a cow’s ability to be biologically, economically, and environmentally efficient. Furthermore, in an increasingly volatile climate, an animal’s genetic merit must be considered in the context of its environment. This review discusses the complex problem of cow efficiency and how the industry can leverage genetic selection tools to improve these traits.
University Demonstration Program for Developing Beef Replacement Heifers on Cool-Season Forages in Alabama
Authors: M. Marks, M. Stanford, L. Kriese-Anderson, M. Mullenix, and J. Rhinehart
Beef replacement heifer development programs offer a tool to Extension educators to demonstrate best management practices associated with nutrition and reproductive management of beef females. Using high-quality, regionally adapted forage species may help support animal growth and performance during the development phase and model an economical method of providing the nutritional base for heifers when these practices are adopted on-farm. Utilizing a custom heifer development program can demonstrate best management practices related to nutrition, reproduction, and health management, while reducing the need for producers to maintain multiple herd sires, facilities and/or paddocks to develop heifers separate from the main herd.
Bacterial Communities of the Uterus and Rumen During Heifer Development With Protein Supplementation
Authors: Taylor B. Ault-Seay, Kiernan J. Brandt, Madison T. Henniger, Rebecca R. Payton, Daniel J. Mathew, Sarah E. Moorey, F. Neal Schrick, Ky G. Pohler, Timothy P. L. Smith, Justin D. Rhinehart, Liesel G. Schneider, Kyle J. McLean, and Phillip R. Myer
Bacterial communities play major roles in rumen and uterine function toward optimal animal performance and may be affected by changes occurring during heifer development such as nutritional supplementation for optimal growth and the attainment of puberty. The effect of different levels of protein supplementation on ruminal and uterine bacterial communities following weaning was examined through first breeding of heifers. Protein supplementation did not impact microbial diversity measures but did affect the abundance of individual bacterial phyla and genera that may provide future opportunities to manipulate bacterial community composition and maximize productivity.
The Effects of Differing Nutritional Levels and Body Condition Score on Scrotal Circumference, Motility, and Morphology of Bovine Sperm
Authors: Taylor D. Harrison, Elizabeth M. Chaney, Kiernan J. Brandt, Taylor B. Ault-Seay, Liesel G. Schneider, Lew G. Strickland, F. Neal Schrick, and Kyle J. McLean
Bulls often experience various levels of nutrient availability throughout the year. Nutritional management is a critical factor on overall ejaculate composition and the ability to get females pregnant. We hypothesized that differing nutritional levels and body condition score (BCS) affect reproductive fertility parameters in bulls. Overall, nutritional treatments influenced semen quality at different adiposity and BCS levels that bulls undergo in normal production scenarios.
Valuation of Genomic-Enhanced Expected Progeny Differences in Bull Purchasing
Authors: Taylor Thompson, Christopher N. Boyer, Charles C. Martinez, Troy N. Rowan, and Justin Rhinehart
We estimate a hedonic pricing model to determine producers’ value for bull expected progeny differences (EPDs), genomic-enhanced EPDs, and phenotypic traits. Birth weight EPD, ribeye area EPD, sale weight, age, frame score, and other factors had a statistically significant impact on bull prices. GE-EPDs were not associated with a change in the bull sales prices expect for weaned calf value and birth weight EPDs. Including weaned calf value and GE-EPDs in a bull hedonic pricing model provides a unique contribution. The results from this work will inform educational programming for bull purchasers on using new economic selection indices and GE-EPDs.
Endometrial Gene Expression in Response to Lipopolysaccharide Between Estrous Cycle Phases and Uterine Horns in Cattle
Authors: Taylor B. Ault-Seay, Rebecca R. Payton, Sarah E. Moorey, Ky G. Pohler, F. Neal Schrick, Elizabeth A. Shepherd, Brynn H. Voy, Kurt H. Lamour, Daniel J. Mathew, Phillip R. Myer, and Kyle J. McLean
Uterine bacterial community abundances shift throughout the estrous cycle, potentially altering the immunological environment of the uterus and impacting subsequent fertility. The objective of the current study was to evaluate the immunological impact of lipopolysaccharide, as a model for potentially pathogenic bacteria, throughout the uterine endometrium between the luteal and follicular phase of the estrous cycle. Therefore, altered immunological environment of the uterus in response to bacteria at different estrous cycle stages may lead to differences in reproductive success.
A Call for the Development of a Sustainable Pest Management Program for the Economically Important Pest Flies of Livestock: a Beef Cattle Perspective
Authors: K. V. Smith, K. L. DeLong,1 C. N. Boyer, J. M. Thompson, S. M. Lenhart, W. C. Strickland, E. R. Burgess, Y. Tian, J. Talley, E. T. Machtinger, and R. T. Trout Fryxell
Filth fly pests have a substantial impact on livestock production; annual losses from filth flies were estimated at over US$1.5 billion in 1981. Knowing filth fly management and animal production have changed significantly over the past 40 yr, our objective is to lay the foundation for the development of a transdisciplinary integrated pest management (IPM) approach that considers the economics of controlling flies in animal production, with most of the examples provided towards beef cattle production systems. By performing an in-depth literature review, it is our goal to highlight losses and expenditures associated with the damages caused by these flies, discuss current management strategies for the system, and propose industry needs in terms of research gaps and producer education to enhance sustainable livestock production.
Endometrial Gene Expression in Response to Lipopolysaccharide Between Estrous Cycle Phases and Uterine Horns in Cattle
Authors: Taylor B. Ault-Seay, Rebecca R. Payton, Sarah E. Moorey, Ky G. Pohler, F. Neal Schrick, Elizabeth A. Shepherd, Brynn H. Voy, Kurt H. Lamour, Daniel J. Mathew, Phillip R. Myer, and Kyle J. McLean
Uterine bacterial community abundances shift throughout the estrous cycle, potentially altering the immunological environment of the uterus and impacting subsequent fertility. The objective of the current study was to evaluate the immunological impact of lipopolysaccharide, as a model for potentially pathogenic bacteria, throughout the uterine endometrium between the luteal and follicular phase of the estrous cycle. Therefore, altered immunological environment of the uterus in response to bacteria at different estrous cycle stages may lead to differences in reproductive success.
Factors Influencing Use and Frequency of Rotational Grazing for Beef Cattle in Tennessee
Authors: Christopher N. Boyer, Dayton M. Lambert, Andrew P. Griffith, and Christopher D. Clark
This study determines which factors are associated with the use of rotational grazing and the frequency with which Tennessee producers rotate cattle during the summer months. Survey data were used to estimate an ordered response model with sample selection. Most respondents used rotational grazing, and the most frequent rotational schedule was rotating cattle one to two times per month. Factors including labor, capital, knowledge, and water availability influenced the use of rotational grazing and the frequency of rotating cattle. The insights from this study can inform the development of incentives to promote more intensive use of rotational grazing.
The Effects of Differing Nutritional Levels and Body Condition Score on Scrotal Circumference, Motility, and Morphology of Bovine Sperm
Authors: Taylor D. Harrison, Elizabeth M. Chaney, Kiernan J. Brandt, Taylor B. Ault-Seay, Liesel G. Schneider, Lew G. Strickland, F. Neal Schrick, and Kyle J. McLean
Bulls often experience various levels of nutrient availability throughout the year. Nutritional management is a critical factor on overall ejaculate composition and the ability to get females pregnant. Sperm morphology fluctuated throughout nutritional periods, whereas motility was not affected. Nutritionally preparing bulls for the breeding season is vital to ensure optimal fertility by increasing or maintaining slightly elevated BCS. Within the current study, the treatments resembled the nutritional levels and potentially the morphological and motility effects that could occur during the breeding season. Overall, nutritional treatments influenced semen quality at different adiposity and BCS levels that bulls undergo in normal production scenarios. Further studies are needed to fully understand the long-term impacts on the ejaculate due to sire diet and reproductive efficiency.
Costs of Horn Fly Control for Cow-calf Producers in Tennessee and Texas
Authors: K. V. Smith, K. L. DeLong, A. P. Griffith, C. N. Boyer, C. C. Martinez, S. M. Schexnayder, and R. T. Trout-Fryxell
Having Angus cattle and larger herd sizes were associated with lower costs per head spent on horn fly management. Producers who did not consider horn flies to be a problem until greater quantities of flies were present on the animal spent 15% less per head on managing horn flies. In terms of horn fly control methods, feed through insecticides increased horn fly costs the most, followed by using ear tags. This is the first known research to estimate horn fly management costs among cattle producers.
The Effects of Protein Level on Cytokines and Chemokines in the Uterine Environment of Beef Heifers During Development
Authors: Taylor B. Ault-Seay, Taylor D. Harrison, Kiernan J. Brandt, Rebecca R. Payton, Liesel G. Schneider, Phillip R. Myer, Justin D. Rhinehart, Louisa A. Rispoli, and Kyle J. McLean
The development of replacement heifers is crucial for breeding success and herd efficiency. Nutritional management can affect not only reproductive development but also the inflammatory status of the uterine environment, which may impact reproductive functions such as pregnancy establishment and development. Cytokines and chemokines fluctuated due to physiological changes occurring during development. Further research is needed to determine the influence of nutrition on uterine inflammation and long-term impacts on reproductive function.
Correlation between Pre-Ovulatory Follicle Diameter and Follicular Fluid Metabolome Profiles in Lactating Beef Cows
Authors: Casey C. Read, Lannett Edwards, Neal Schrick, Justin D. Rhinehart, Rebecca R. Payton, Shawn R. Campagna, Hector F. Castro, Jessica L. Klabnik, Emma J. Horn and Sarah E. Moorey
Induced ovulation of small pre-ovulatory follicles reduced pregnancy rates, embryo survival, day seven embryo quality, and successful embryo cleavage in beef cows undergoing fixed time artificial insemination. Individual and pathway enrichment analysis of significantly correlated metabolites suggest that altered glucose and amino acid metabolism likely contribute to reduced developmental competence of oocytes when small pre-ovulatory follicles undergo induced ovulation.
Replacing Late-Calving Beef Cows to Shorten Calving Season
Authors: Christopher N. Boyer, Kenny Burdine, Justin Rhinehart, and Charley Martinez
We simulated beef cattle producers’ returns to shortening a 120-day calving season to 45 and 60 days by replacing late-calving cows for two herd sizes. We developed dynamic simulation models to consider production and price risk. We explored outcomes from annually replacing 10% or 20% of the late-calving cows to reach the desired calving-season length. The optimal scenario depends on herd size and whether the producer wants to maximize profits or certainty equivalent. The smaller herd benefited more from shortening calving season relative to the large herd.
Evaluation of Grazing or Reduced Feeding Frequency Supplementation Systems for Wintering Cow-Calf Pairs
Authors: K. M. Mason, M. K. Mullenix, K. Kelley, J. Elmore, and J. L. Jacobs
Reducing labor or feed costs are priorities for profitable beef cow-calf systems in the Southeast. Nutritional management strategies such as extending the grazing season, reducing feeding frequency, or feeding in bulk can accomplish this goal during the winter management season. This study indicates that rotational grazing of winter annuals, feeding fiber-based supplements that are low in non-structural carbohydrates every other day as opposed to daily, or bulk feeding whole cottonseed with access to hay are all viable options in terms of nutritive value and cattle performance. Producers should consider available feed sources, land area, and labor availability to determine which winter nutritional management system would fit best into their operation.
Horn Fly- Biology, Management, and Future Research Directions
Authors: Gary J. Brewer, Dave J. Boxler, Luísa N. Domingues, Rebecca T. Trout-Fryxell, Chris Holderman, Kelly M. Loftin, Erika Machtinger, Brandon Smythe, Justin L. Talley, and Wes Watson
The horn fly is one of the most important external parasites of cattle in North America and elsewhere. Horn fly adults have an intimate association with cattle, their primary host. With their often-high numbers and by feeding up to 38 times per day per fly, horn flies stress cattle. The resulting productivity loss is valued at more than 2.3 billion USD in the United States.
Face Fly- Biology, Pest Status, Current Management Prospects, and Research Needs
Authors: R. T. Trout-Fryxell, R. D. Moon, D. J. Boxler, and D. W. Watson
Face flies are native to Europe and Central Asia were unintentionally introduced into North America and became pests of pastured beef cattle, dairy cattle, and horses. Female and male flies use their sponging proboscis with prestomal teeth to feed around moist, mucus membranes of an animal’s face and other body parts.
Development and Validation of a Neural Network for the Automated Detection of Horn Flies on Cattle
Authors: E. T. Psota, E. K. Luc, G. M. Pighetti, L. G. Schneider, R. T. Trout-Fryxell, J. W. Keele, and L. A. Kuehn
When the number of horn flies that blood feed on cattle exceeds the economic threshold, they can adversely affect the health and wellbeing of their hosts. Excessive horn fly burdens also lead to reduced weight gain and, consequently, diminished profits for livestock producers. Effective management and treatment require reliable surveillance methods for estimating the degree of horn fly burden (i.e., counting the number of flies on cattle). An examination of individual images where the method was closest to and farthest from the human counts provides valuable insights regarding photographic processes that lead to success and failure.
Differential Transcript Profiles in Cumulus-Oocyte Complexes Originating from Pre-Ovulatory Follicles of Varied Physiological Maturity in Beef Cows
Authors: Sarah E. Moorey, Jenna M. Monnig, Michael F. Smith, M. Sofia Ortega, Jonathan A. Green, Ky G. Pohler, G. Alan Bridges, Susanta K. Behura, and Thomas W. Geary
Small dominant follicle diameter at induced ovulation, but not at spontaneous ovulation, decreased pregnancy rate, fertilization rate, and day seven embryo quality in beef cows. We hypothesized that the physiological status of the follicle at GnRH-induced ovulation has a direct effect on the transcriptome of the Cumulus-Oocyte complex, thereby affecting oocyte competence and subsequent embryo development. The objective of this study was to determine if the transcriptome of oocytes and associated cumulus cells (CC) differed among small (11.7 mm) and large follicles (12.7 mm) exposed to a GnRH-induced gonadotropin surge and follicles (11.7–14.0 mm) exposed to an endogenous gonadotropin surge (spontaneous follicles).
The Effects of Protein Level on Cytokines and Chemokines in the Uterine Environment of Beef Heifers During Development
Authors: Taylor B. Ault-Seay, Taylor D. Harrison, Kiernan J. Brandt, Rebecca R. Payton, Liesel G. Schneider, Phillip R. Myer, Justin D. Rhinehart, Louisa A. Rispoli, and Kyle J. McLean
The development of replacement heifers is crucial for breeding success and herd efficiency. Nutritional management can affect not only reproductive development but also the inflammatory status of the uterine environment, which may impact reproductive functions such as pregnancy establishment and development. The study herein evaluated the concentration of cytokines and chemokines in the uterus of heifers supplemented with different levels of protein.
Replacing Late-Calving Beef Cows to Shorten Calving Season
Authors: Christopher N. Boyer, Kenny Burdine, Justin D. Rhinehart, and Charley Martinez
We simulated beef cattle producers’ returns to shortening a 120-day calving season to 45 and 60 days by replacing late-calving cows for two herd sizes. We developed dynamic simulation models to consider production and price risk. We explored outcomes from annually replacing 10% or 20% of the late-calving cows to reach the desired calving-season length. The optimal scenario depends on herd size and whether the producer wants to maximize profits or certainty equivalent. The smaller herd benefited more from shortening calving season relative to the large herd.
Rapid Discovery and Detection of Haemaphysalis longicornis through the Use of Passive Surveillance and Collaboration: Building a State Tick-Surveillance Network
Authors: Rebecca T. Trout Fryxell, Dene N. Vann, Rebecca A. Butler, Dave J. Paulsen, Jennifer G. Chandler, Micah P. Willis, Heidi M. Myrosdick, John J. Schaefer, Richard W. Gerhold, Daniel M. Grove, Jennie Z. Ivey, Kevin W. Thompson, Roger D. Applegate, Joy Sweaney, Sterling Daniels, Samantha Beaty, Douglas Balthaser, James D. Freye II, James W. Mertins, Daniel L. Bonilla, and Kevin Lahmers
Between March 2019 and February 2020, Asian long-horned ticks were discovered and collected for the first time in one middle and seven eastern Tennessee counties, facilitated by a newly developed passive and collaborative tick-surveillance network. Network collaborators included federal, state, county, university, and private resource personnel working with companion animals, livestock, and wildlife.
Evaluation of Reproductive Tract Cytokines in Post-partum Beef Cows Relating to Reproductive Microbiota and Fertility Outcomes
Authors: Rebecca K. Poole, Taylor B. Ault-Seay, Rebecca R. Payton, Phillip R. Myer, Andrea S. Lear, and Ky G. Pohler
The activity of the immune system in the reproductive tract has been proven to be crucial in the response to uterine diseases, normal reproductive functions, and tolerance to the allogeneic fetus during pregnancy. The objectives of the current study were to (1) evaluate uterine and vaginal cytokine concentrations in postpartum cows undergoing estrus synchronization followed by timed artificial insemination, and (2) correlate bacterial communities with cytokine concentrations.
Data of Bacterial Community Dynamics Resulting from Total Rumen Content Exchange in Beef Cattle
Authors: Brooke A. Clemmons, Madison T. Henniger, and Phillip R. Myer
Extensive efforts have been made to characterize the rumen microbiome under various conditions. However, few studies have addressed the long-term impacts of ruminal microbiome dysbiosis and the extent of host control over microbiome stability. These data can also inform host-microbial symbioses. The objective was to develop preliminary data to measure the changes that occur in the rumen bacterial communities following a rumen content exchange to understand the effects major perturbations may impart upon the rumen microbiome, which may be host-driven.
Ruminal Protozoal Populations of Angus Steers Differing in Feed Efficiency
Authors: Brooke A. Clemmons, Sung B Shin, timothy P. L. Smith, Mallory M. Embree, Brynn H. Voy, Liesel G. Schneider, Dallas R. Donohoe, Kyle J. McLean, and Phillip R. Myer
The rumen protozoa have been demonstrated to enhance methanogenesis and impact intraruminal recycling of microbial protein. However, they are also known to contribute to fiber degradation and the stabilization of ruminal pH changes. The apparent metabolic impact of ciliated protozoa in the rumen may contribute to the variation in feed efficiency.
Spray and Pour-On Acaricides Killed Tennessee (United States) Field-Collected Haemaphysalis longicornis Nymphs (Acari: Ixodidae) in Laboratory Bioassays
Authors: R. A. Butler, J. G. Chandler, K.M. Vail, C.J. Holderman, and R.T. Trout Fryxell
The Asian longhorned tick (ALT) is an exotic and invasive tick species presenting a health and economic threat to the United States cattle industry due to its ability to transmit pathogens and infest hosts in large numbers. The objective of this study was to evaluate available products at causing ALT mortality in a laboratory bioassay. The efficacy of products was evaluated at label rates using ALT nymphs collected from a cattle farm in eastern Tennessee in two different bioassays (spray or dip) against untreated controls.
A Unique Academic–Government Collaboration Yields First Report of Detailed Habitat Description for Haemaphysalis longicornis (Ixodida: Ixodidae) in Madison County, KY
Authors: J. T. Vogt, B. D. Allen, D. Paulsen, and R. T. Trout Fryxell
Asian longhorned tick, was collected in Madison County, Kentucky, United States as part of an ongoing collaborative-tick surveillance project. This is the first collection of this invasive tick that includes ancillary data on habitat and landscape features derived from the USDA Forest Service, Forest Inventory and Analysis program.
Bred Heifer Price Determinants in the Southeast
Authors: Christopher Boyer, Andrew P. Griffith, Jada M. Thompson, Justin Rhinehart, Kenneth H. Burdine, and Kevin Laurent
Price determinants for bulls, cows, and feeder cattle are well established in the literature but there has been little research on bred heifer price determinants and specifically the impact of feeder cattle prices on the purchase price of bred heifers. Pregnancies resulting from artificial insemination did increase the value of fall-calving heifers but did not impact spring-calving heifer prices. Heifer feeder cattle prices the day of the sale positively influenced the price of spring-and fall-calving bred heifers.
Effects of Management System on Beef Heifer Growth and Reproductive Performance
Authors: Parker A. Henley, Frank A. Ireland, Igor F. Canisso, J. Lannett Edwards, and Daniel W. Shike
The objectives of this experiment were to compare the growth and reproductive performance of replacement fall-calving beef heifers developed in two common Midwest systems (dry lot developed and grazing E+ with daily supplementation) with two alternative strategies (grazing E+ with daily supplementation from the midpoint of treatment period until breeding, or grazing NE+). This study evaluated the effect of heifer development system on body weight, body condition score, fescue toxicosis symptoms, reproductive performance, and subsequent calf growth of fall-calving beef heifers.
Form of Supplemental Selenium in Vitamin-Mineral Premixes Differentially Affects Early Luteal and Gestational Concentrations of Progesterone, and Postpartum Concentrations of Prolactin in Beef Cows
Authors: Sarah Carr, Yang Jia, Benjamin Crites, Charles Hamilton, Walter Burris, J. Lannett Edwards, James Matthews, Phillips J. Bridges
Soils with marginal to deficient levels of selenium (Se) are widespread in the northwest, northeast, and southeast US. Supplementation to the diet of forage-grazing beef cattle with a vitamin-mineral mix containing additional Se is recommended in these geographic regions. We have reported that the form of supplemental Se provided to Angus-cross beef cows can affect circulating levels of progesterone (P4) on day 6 of the estrous cycle, a time when increased P4 is known to promote fertility. The objectives of this study were to (1) confirm and expand upon our initial report that the form of Se provided to cows affects early luteal-phase concentrations of systemic P4, (2) determine the effects of the form of Se on concentrations of P4 during gestation, and (3) determine the effects of the form of Se on concentrations of prolactin (PRL) during lactation.
Does the Tennessee Master Beef Producer Program Impact Technical Efficiency?
Authors: Christopher N. Boyer, Edward Yu, Justin D. Rhinehart, Amelia Ahles, and Mackenzie Gill
The impacts of the Tennessee Master Beef Producer (MBP) program on the technical efficiency (TE) of Tennessee beef production was estimated using county-level data in 2007, 2012, and 2017. A two-stage, double bootstrap method was used to measure TE by county and year, and identify any statistical relationship between MBP and TE. TE of beef production changed statewide during this time period. We found a positive relationship in MBP participation and county-level TE of beef production. Results are helpful in targeting locations for future education and provide evidence on the effectiveness of MBP.
Evaluating Optimal Purchasing and Selling Decisions of Beef Cattle Replacement Females
Authors: Christopher N. Boyer, Andrew P. Griffith, and Karen L. DeLong
The objective of this research was to determine the optimal age and pregnancy status for buying and selling replacement of beef females for risk-neutral and risk-averse producers. This research offers unique insight into how pregnancy status and age at sale impacts the animal’s NPV while considering risk. These results have implications for educating producers on purchasing and selling decisions of heifers and cows as well as for lenders who finance these purchases.
Reproductive Failure and Long-Term Profitability of Spring- and Fall-Calving Beef Cows
Authors: Christopher N. Boyer, Andrew P. Griffith, and Karen L. DeLong
We determined how reproductive failure impacts the long-term profitability of beef cows in spring and fall-calving herds. Simulation models were established to generate distributions of net present value, payback periods, and breakeven prices of calves when a dam fails to wean zero, one, or two calves over her life. Results indicate that giving a dam another calving opportunity after failing to wean a calf would likely result in her being unprofitable. A producer would be better off selling the open dam than giving her another chance to breed. This illustrates the value in selecting replacement heifers based on fertility.
Rumen and Serum Metabolomes in Response to Endophyte-Infected Tall Fescue Seed and Isoflavone Supplementation in Beef Steers
Authors: Taylor B. Ault-Seay, Emily A. Melchior-Tiffany, Brooke A. Clemmons, Juan F. Cordero, Gary E. Bates, Michael D. Flythe, James L. Klotz, Huihua Ji, Jack P. Goodman, Kyle J. McLean, and Phillip R. Myer
Fescue toxicosis impacts beef cattle production via reductions in weight gain and muscle development. Isoflavone supplementation has displayed potential for mitigating these effects. The objective of the current study was to evaluate isoflavone supplementation with fescue seed consumption on rumen and serum metabolomes.
Rumen Fluid Metabolomics of Beef Steers Differing in Feed Efficiency
Authors: Brooke A. Clemmons, Cameron Martino, Joshua B. Powers, Shawn R. Campagna, Brynn H. Voy, Dallas R. Donohoe, James Gaffney, Mallory M. Embree, and Phillip R. Myer
Beef is the most consumed red meat in the United States, and the US is the largest producer and consumer of beef cattle globally. Feed is one of the largest input costs for the beef cattle industry, accounting for 40–60% of the total input costs. Identifying methods for improving feed efficiency in beef cattle herds could result in decreased cost to both producers and consumers, as well as increased animal protein available for global consumption.
Uterine and Vaginal Bacterial Community Diversity Prior to Artificial Insemination between Pregnant and Nonpregnant Postpartum Cows
Authors: Taylor B. Ault, Brooke A. Clemmons, Sydney T. Reese, Felipe G. Dantas, Gessica A. Franco, Tim P. L. Smith, J. Lannett Edwards, Phillip R. Myer, and Ky G. Pohler
The present study evaluated the bovine vaginal and uterine bacterial community diversity and its relationship to fertility. Postpartum beef cows (n = 68) were synchronized beginning on day −21 and ending with timed artificial insemination (TAI) on day 0. Pregnancy was diagnosed 30 d after TAI. Uterine and vaginal flushes were collected on day −21, −9, and −2 for bacterial DNA extraction to sequence the V1 to V3 hypervariable regions of the 16S rRNA gene.
Using Pregnancy Associated Glycoproteins (PAG) for Pregnancy Detection at Day 24 of Gestation in Beef Cattle
Authors: R. V. Oliveira Filho, G. A. Franco, S. T. Reese, F. G. Dantas, P. L. P. Fontes, R. F. Cooke, Justin D. Rhinehart, Kevin W. Thompson, and Ky G. Pohler
The objective of this experiment was to determine if circulating concentrations of pregnancy associated glycoproteins (PAG) on day 24 of gestation can be utilized to diagnose pregnancy and embryo viability in beef cattle. Postpartum beef cows (n ¼ 677) and heifers (n ¼ 127) were exposed to a 7-day COSynch þ CIDR estrus synchronization protocol followed by fixed-time AI (FTAI) on day 0.
Risk and Returns from Grazing Beef Cattle on Warm-Season Grasses in Tennessee
Authors: Christopher N. Boyer, Katelynn Zechiel, Patrick D. Keyser, Justin D. Rhinehart, and Gary E. Bates
A possible way to extend grazing in this region is to use warm-season grasses (WSGs) during summer to complement tall fescue. Therefore, the objective of this study is to compare the profitability and risk associated with grazing beef stocker cattle on five WSGs: a combination of big bluestem and indiangrass, switchgrass, eastern gamagrass, bermudagrass, and crabgrass. Data comes from a 3-yr (2014–2016) grazing experiment at two locations in Tennessee.
Price Determinants of Performance-Tested Bulls over Time
Authors: Christopher N. Boyer, Kelsey Campbell, Andrew P. Griffith, Karen L. DeLong, Justin D. Rhinehart, and David Kirkpatrick
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.
Rumen Bacteria and Serum Metabolites Predictive of Feed Efficiency Phenotypes in Beef Cattle
Authors: Brooke A. Clemmons, Cameron Martino, Joshua B. Powers, Shawn R. Campagna, Brynn H. Voy, Dallas R. Donohoe, James Gaffney, Mallory M. Embree, and Phillip R. Myer
The rumen microbiome is critical to nutrient utilization and feed efficiency in cattle. Consequently, the objective of this study was to identify microbial and biochemical factors in Angus steers affecting divergences in feed efficiency using 16S amplicon sequencing and untargeted metabolomics.
Temporal Stability of the Ruminal Bacterial Communities in Beef Steers
Authors: Brooke A. Clemmons, Cameron Martino, Liesel G. Schneider, Josh Lefler, Mallory M. Embree, and Phillip R. Myer
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.
Winter Grazing of Stockpiled Native Forages During Heifer Development Delays Body Weight Gain Without Influencing Final Pregnancy Rates
Authors: Zachary D. McFarlane, Emily R. Cope, Jeremy D. Hobbs, Renta N. Oakes, Ky G. Pohler, and J. Travis Mulliniks
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.
Estimating Restaurant Willingness to Pay for Local Beef
Authors: Lettie C. McKay, Karen L. DeLong, Kimberly L. Jensen, Andrew P. Griffith, Christopher N. Boyer, and Dayton M. Lambert
This study contributes to understanding local food supply chains and provides a framework for future studies of restaurant willingness to pay for local foods.
Cow-Calf Producers’ Willingness to Pay for Bulls Resistant to Horn Flies
Authors: Lettie McKay, Karen L. DeLong, Susan Schexnayder, Andrew P. Griffith, David B. Taylor, Pia Olafson, and R. T. Trout-Fryxell
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.
Beef Cattle Farmers’ Marketing Preferences For Selling Local Beef
Authors: Karen L. DeLong, Kimberly L. Jensen, Andrew P. Griffith, and Elizabeth McLeod
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
Authors: Meagan G. Merritt, Karen L. DeLong, Andrew P. Griffith, and Kimberly L. Jensen
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
Authors: Elizabeth McLeod, Kimberly Jensen, Andrew P. Griffith, and Karen L. DeLong
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.
Microbiomes in Ruminant Protein Production and Food Security
Authors: Phillip R. Myer, Brooke A. Clemmons, Liesel G. Schneider, and Taylor B. Ault
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.
Effects of Endophyte-infected Tall Fescue Seed and Red Clover Isoflavones on Rumen Microbial Populations and Physiological Parameters of Beef Cattle
Authors: Emily A. Melchior, Jason K. Smith, Liesel G. Schneider, J. Travis Mulliniks, Gary E. Bates, Michael D. Flythe, James L. Klotz, Huihua Ji, Jack P. Goodman, Amanda R. Lee, J. Marc Caldwell, and Phillip R. Myer
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
Authors: Emily A. Melchior, Jason K. Smith, Liesel G. Schneider, J. Travis Mulliniks, Gary E. Bates, Zachary D. McFarlane, Michael D. Flythe, James L. Klotz, Jack P. Goodman, Huihua Ji, and Phillip R. Myer
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
Authors: Emily A. Melchior and Phillip R. Myer
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.
Factors Associated with Seroprevalence of Anaplasma Marginale in Kentucky Cattle
Authors: Chika C. Okafor, Samantha L. Collins, Joseph A. Daniel, Benton Harvey, Xiaocun Sun, Johann F. Coetzee, and Brian K. Whitlock
Bovine anaplasmosis (BA) is tick-borne disease of cattle caused by Anaplasma marginale and it remains an economically important disease in the United States. We have anecdotal information that Veterinary Feed Directive prescriptions in Kentucky 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
Authors: Bradley A. Mullens, Nancy C. Hinkle, Rebecca Trout-Fryxell, and Kateryn Rochon
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
Authors: D. P. Theuret and R. T. Trout-Fryxell
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.
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
Authors: Jeremy D. Hobbs, S. R. Edwards, Emily R. Cope, Zachary D. McFarlane, Ky G. Pohler, and J. Travis Mulliniks
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 body weight (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
Authors: S. A. Lockwood, H. G. Kattesh, J. D. Rhinehart, L. G. Strickland, P. D. Krawczel, J. B. Wilkerson, F. D. Kirkpatrick, and A. M. Saxton
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.
High Milk Production Decreases Cow-Calf Productivity Within a Highly Available Feed Resource Environment
Authors: S. R. Edwards, J. D. Hobbs, and J. T. Mulliniks
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.
Is the Natural Label Misleading? Examining Consumer Preferences for Natural Beef
Authors: Konstantinos G. Syrengelas, Karen L. DeLong, Carola Grebitus, and Rodolfo M. Nayga Jr.
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.
Replacement Beef Cow Valuation under Data Availability Constraints
Authors: Amy D. Hagerman, Jada M. Thompson, Charlotte Ham, and Kamina K. Johnson
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
Authors: Minfeng Tang, Karen E. Lewis, Dayton M. Lambert, Andrew P. Griffith, and Christopher N. Boyer
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
Authors: Meagan G. Merritt, Andrew P. Griffith, Christopher N. Boyer, and Karen E. Lewis
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.
Altering the Gut Microbiome of Cattle: Considerations of Host-Microbiome Interactions for Persistent Microbiome Manipulation
Authors: Brooke A. Clemmons, Brynn H. Voy, and Phillip R. Myer
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.
Effect of Forage Species and Supplement Type on Rumen Kinetics and Serum Metabolites in Growing Beef Heifers Grazing Winter Forage
Authors: Zachary D. McFarlane, R. P. Barbero, R. L. G. Nave, E. B. Maheiros, R. A. Reis, and J. Travis Mulliniks
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
Authors: Brooke A. Clemmons, Robert L. Mihelic, Ronique C. Beckford, Joshua B. Powers, Emily B. Powers, Emily A. Melchoir, Zachary D. McFarlane, Emily R. Cope, Mallory M. Embree, J. Travis Mulliniks, Shawn R. Campagna, Brynn H. Voy, and Phillip R. Myer
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
Authors: Phillip R. Myer, H. C. Freetly, J. E. Wells, T. P. L. Smith, and L. A. Kuehn
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
Authors: M. A. Green, B. K. Whitlock, J. L. Edwards, E. J. Scholljegerdes, and J. T. Mulliniks
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.
Prevalence of Tritrichomonas foetus in Tennessee Bulls
Authors: Chika C. Okafor, Lew G. Strickland, Brittni M. Jones, Stephen Kania, David E. Anderson, and Brian K. Whitlock
The prevalence of bovine trichomonosis (BT) in Tennessee 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.
Does Prepartum Supplemental Feed Impact Beef Cattle Profitability Through Finishing?
Authors: Karen E. Lewis, Andrew P. Griffith, Christopher N. Boyer, and Justin D. Rhinehart
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.
Effects of Pre-weaning Feed Supplementation and Total Versus Fenceline Weaning on the Physiology and Performance of Beef Steers
Authors: C. Campistol, H. G. Kattesh, J. C. Waller, E. L. Rawis, J. D. Arthington, J. A. Carroll, G. M. Pighetti, and A. M. Saxton
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.
Bred Heifer Price Determinants in the Southeast
Authors: Christopher N. Boyer, Andrew P. Griffith, Jada M. Thompson, Justin D. Rhinehart, and Kenneth H. Burdine
Price determinants for bulls, cows, and feeder cattle are well established in the literature but there has been little research on bred heifer price determinants and specifically the impact of feeder cattle prices on the purchase price of bred heifers. We estimated the impact of reproductive characteristics and feeder cattle prices on bred heifer prices for beef production.
Profitability of Beef and Biomass Production from Native Warm-Season Grasses in Tennessee
Authors: Joe K. Lowe II, Christopher N. Boyer, Andrew P. Griffith, Gary E. Bates, Patrick D. Keyser, John C. Waller, James A. Larson, and William M. Backus
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.
Microbial Community Profiles of the Colon from Steers Differing in Feed Efficiency
Authors: Phillip R. Myer, James E. Wells, Timothy P. L. Smith, Larry A. Kuehn, and Harvey C. Freetly
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
Authors: Phillip R. Myer, James E. Wells, Timothy P. L. Smith, Larry A. Kuehn, and Harvey C. Freetly
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
Authors: S. A. Lockwood, H. G. Kattesh, P. D. Krawczel, F. D. Kirkpatrick, A. M. Saxton, J. D. Rhinehart, and J. B. Wilkerson
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.
Relationships Among Temperament Behavior, and Growth During Performance Testing of Bulls
Authors: S. A. Lockwood, H. G. Kattesh, P. D. Krawczel, F. D. Kirkpatrick, A. M. Saxton, J. D. Rhinehart, and J. B. Wilkerson
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.
