Texas Beef Research Articles

Probabilistic Risk Assessment of Polioencephalomalacia from Texas Beef Consuming Rations Containing Multiple Sources of Dietary Sulfur.

The purpose of this probabilistic assessment was to estimate the risk of sulfur-induced polioencephalomalacia (S-PEM) for beef raised across Texas, from a dietary perspective. Ruminant nutritionists in Amarillo, TX, formulated two typical nutritional regimens based on cattle production stages, each containing six feed ingredients and well water. The Office of the Texas State Chemist (OTSC), National Research Council (NRC), and the published literature provided S data for feed ingredients. The Texas Water Development Board provided data for S content in Texas well water, categorized into twelve districts established by the Texas A&M AgriLife Research Extension Service. The S-PEM risk was estimated at five different eNDF levels ranging from 0% to 8% in 2% increments, using rumen degradable S (RDS) as an input value. Findings identified cattle raised in the South Plains district as the most susceptible population to S toxicity, with beef in the finishing production stage experiencing increased sensitivity. The most potential (MP) risk scenario suggested that the S-PEM risk could reach 28.5% for growers and 100% for finishers. Results further revealed that when S concentrations in well water exceeded 14.5 mg/L, water became the greatest contributor to RDS content for Texas beef, suggesting that high S content in well water is the most prominent concern for Texas beef.

Mexican consumers' perceptions and preferences for US and Texas beef

AbstractThe United States (US) is the world's largest beef producer and the third‐largest exporter. Beef production is also an important component of Texas history and economy. However, the US beef industry faces several challenges, including declining domestic consumption and competition for export markets. A potential strategy to overcome these challenges is promoting US beef products in international markets. Mexico is one of the markets of importance as it is the third‐largest export destination for US beef. In this study, we explored the use of “US” country of origin and “Texas” geographic indication information for consumer advertising of beef in Mexico. It was posited that Texas's international reputation as a cattle‐producing region could be used to promote Texas beef products. Data for this study were collected in 2019 and 2020 using an online survey of 1021 Mexican food shoppers. The survey included a choice experiment with 12 hypothetical choice scenarios of beef steak with different product attributes and prices. The product attributes considered were place of origin, food safety level, and production practices. Mexican consumers were found to have a strong preference for domestic beef products. Moreover, Mexican consumers are willing to pay $1.16 and $1.18/lb for enhanced food safety and natural production practices. Consumers are also willing to pay $0.19/lb more for US–Texas beef than that of US beef. The results of this project provide valuable information for developing marketing strategies and promotion campaigns aiming to improve the competitiveness of US and Texas beef products in foreign markets [EconLit Citations: D12, Q17, Q18].

4 Survey of Mycoplasma Wenyonii Infection in a Texas Beef Cattle Herd

Abstract Mycoplasma wenyonii is hemotrophic bacteria known to cause mild anemia, localized edema, and pyrexia in infected cattle. It has been previously detected in cattle herds across the world, including United States beef herd. Mode of transmission, prevalence, and a full profile of symptoms associated with this species of bacteria have not been established. This case study aimed to elucidate the percentage of infected cattle in a local Erath County beef herd and determine which groups of cattle may have the greatest infection rates. Groups were determined based on sex and age, bull, cow, or unsexed calf. Blood was collected from 4 bulls, 61 cows, and 55 calves from the same producer on the same day. A blood extraction kit that utilized spin column-based nucleic acid purification was used to extract DNA from blood samples. Primers were constructed to be highly specific to the m. wenyonii sequence to avoid confusion with other common mycoplasma species. Extracted m. weyonii DNA was quantified using qPCR. Melt curve analysis was performed to verify the amplicon product size. Standard deviation of the melting point was calculated and selection was made within 2 standard deviations of the control. Animals with any detectable amount of m. wenyonii DNA present in their blood were considered positive for infection for the purposes of this case study. This survey yielded positive results for 2 of the 4 bulls, 19 of the 61 cows, and 0 calves. The lack of positive samples in the calf population suggests that the placenta functions as a barrier to infection. This study provides perspective on the prevalence of this microorganism in Texas cattle populations and serves as a basis for future studies. More investigation is needed to better understand the impact of this bacterial infection on Texas beef cattle producers.

Palatability Assessments of Beef Top Loin Steaks Sourced from Three Quality Grade/Brand Categories from Texas and Non-Texas Processing Establishments

Beef top loin steaks from Top Choice (Modest and Moderate marbling), Choice (primarily Small marbling), and Select (Slight marbling) beef strip loins from Texas and Non-Texas (Kansas, Nebraska, and Colorado) beef processing establishments were obtained to determine the role of source and USDA grade/brand category on consumer sensory panel and Warner-Bratzler shear (WBS) evaluations. The number of strip loins obtained were 58 Texas Top Choice, 54 Texas Choice, and 56 Texas Select and 60 Non-Texas Top Choice, 52 Non-Texas Choice, and 58 Non-Texas Select. There were source × USDA grade/brand category interactions for overall liking (P = 0.012) and tenderness liking (P = 0.002) in which the Texas Top Choice steaks received ratings that did not differ (P > 0.05) from Texas Select steaks but did differ (P < 0.05) from the Non-Texas Top Choice steaks. There were no (P = 0.079) differences in WBS values for steaks from the 2 sources even though the P value approached significance. For USDA quality grade/brand category, there were differences (P < 0.001) in WBS values, but not in the direction one might expect: Choice steaks had the lowest (P < 0.05) WBS values compared with those from Top Choice and Select steaks, which did not differ (P > 0.05) from each other. Percentage dis- tribution of WBS values according to tenderness categories showed that all of the Top Choice and Choice steaks, regardless of source, had values that met the threshold values for Very Tender (WBS < 31.4 N) or Tender (31.4 N < WBS < 38.3 N). While geographic purchasing biases may remain, these data assist in supporting informed decisions regarding palatability and consumer acceptability as functions of beef sourcing.

97 Impact of Regionalized Forage Quality and Quantity and Feed Grain Water Use on the Daily Texas Beef Cattle Water Footprint and Supply Chain Efficiency

Abstract Livestock water use sustainability is a growing concern in the beef cattle sector. The Water Footprint Assessment (WFA) method has been used to quantify the water footprint (WF) of beef products but does not suggest any specific management strategies to decrease the WF of beef cattle (WFB) within and across the beef supply chain. The WFB is primarily influenced by forage and grain production water uses (m3/t), which are directly linked to dry matter (kg/d) and water intake (L/d) and cattle growth (kg/d). Therefore, the objective of this study was to assess the alteration of forage quality and above-ground biomass production (t/ha) of annual ryegrass (Lolium multiflorum) and bermudagrass (Cynodon dactylon), in addition to published WF estimates for corn (Zea mays) and soybean (Glycine max) production (m3/t) on the daily Texas WFB. A dynamic Texas Beef Water Footprint Model (TXWFB) was developed to predict WFB, using the System Dynamic methodology and equations from the Ruminant Nutrition System (RNS) and Beef Nutrient Requirements (NASEM) models. Results indicated that forage and crop biomass production is a high-leverage solution to offset the daily Texas WFB (%∆ = -55 to 130). The alteration of forage TDN had less of an impact on the Texas WFB (%∆ = -39 to 17). An ANOVA with a Tukey Posthoc test indicated that all WFB scenarios were significantly different (P < 0.05) except for the low versus base TDN under low water use conditions scenario. The variability in the use of green and blue waters for grains indicated that the final WFB, in the feedlot phase, may be lower than the WFB in the cow-calf or stocker stages under certain efficiency conditions. Identification of high and low-leverage solutions may help Texas cattle stakeholders implement systemic strategies that aid in the efforts for sustainable beef water use.

The characterization of the cow-calf, stocker and feedlot cattle industry water footprint to assess the impact of livestock water use sustainability

AbstractPerception of freshwater use varies between nations and has led to concerns of how to evaluate water use for sustainable food production. The water footprint of beef cattle (WFB) is an important metric to determine current levels of freshwater use and to set sustainability goals. However, current WFBpublications provide broad WF values with inconsistent units preventing direct comparison of WFBmodels. The water footprint assessment (WFA) methodologies use static physio-enviro-managerial equations, rather than dynamic, which limits their ability to estimate cattle water use. This study aimed to advance current WFA methods for WFBestimation by formulating the WFA into a system dynamics methodology to adequately characterize the major phases of the beef cattle industry and provide a tool to identify high-leverage solutions for complex water use systems. Texas is one of the largest cattle producing areas in the United States, a significant water user. This geolocation is an ideal template for WFBestimation in other regions due to its diverse geography, management-cultures, climate and natural resources. The Texas Beef Water Footprint model comprised seven submodels (cattle population, growth, nutrition, forage, WFB, supply chain and regional water use; 1432 state variables). Calibration of our model replicated initial WFBvalues from an independent study by Chapagain and Hoekstra in 2003 (CH2003). This CH2003v.Texas production scenarios evaluated model parameters and assumptions and estimated a 41–66% WFBvariability. The current model provides an insightful tool to improve complex, unsustainable and inefficient water use systems.

Toward Modeling of Nitrous Oxide Emissions Following Precipitation, Urine, and Feces Deposition on Beef Cattle Feedyard Surfaces

HighlightsNitrous oxide is a greenhouse gas emitted from feedyard pen surfaces.Experiments were conducted to quantify nitrous oxide emissions from precipitation, urine, and feces.Nitrous oxide emissions from urine were about 30% of those from equal amounts of precipitation.Regression equations were developed for empirical modeling of emissions.Abstract. The amount of moisture deposited annually as urine (~320 mm) and feces (~95 mm) on typical semi-arid Texas beef cattle feedyard pens is considerable compared to the regional 470 mm mean annual precipitation. Precipitation is a primary factor affecting nitrous oxide (N2O) emissions from manure, but specific effects of urine and feces deposition are unknown. The objectives of this research were to (1) quantify N2O emissions following precipitation, urine, and feces deposition on a dry feedyard manure surface, and (2) develop equations for future empirical modeling of these emissions. Four experiments (Exp.) were conducted using recirculating flux chambers to quantify N2O emissions. Exp. 1 had treatments (TRT) of water (W), artificial urine (AU), and two urines collected from beef cattle fed high-quality forage (FU) or corn-based concentrate (CU). Exp. 2 had TRT of W, AU, and two feces levels (Fx1 and Fx2). In Exp. 3, N2O emissions were quantified from fresh feces pats. In Exp. 4, the effect of rainfall pH on N2O emissions was evaluated. Results from Exp. 1 showed that the W TRT had the highest mean cumulative N2O emission, while AU, FU, and CU ranged from 31.0% to 70.0% of W on an equal volume-applied basis. There was little correlation between N2O emissions and urine or water nitrogen (N) content. In Exp. 2, W again had the highest cumulative N2O. Cumulative N2O emissions expressed per unit of water added were 29.0, 3.8, 4.5, and 5.1 mg N kg-1 water added for W, AU, Fx1, and Fx2, respectively. In Exp. 3, fresh feces pats emitted no direct N2O, but N2O originated from the dry manure beneath the feces pat due to wetting. In Exp. 4, the highest N2O emissions occurred at pH 5 and pH 8, with lower emissions at pH 6 and pH 7. This research has shown that the addition of moisture to the pen surface from urine and feces contributes considerably to N2O emissions as compared to precipitation alone. The following recommendations were developed for future empirical modeling purposes: (1) N2O emissions from urine should be calculated as 32.7% of those emissions from the equivalent mass deposition of water, and (2) N2O emissions resulting from the mass of water in feces should be calculated as 15.6% of those emissions from the equivalent mass deposition of water. Keywords: Beef cattle, Greenhouse gas, Manure, Nitrous oxide, Urine, Precipitation.

144 A modeling framework to assess the impact of the texas beef cattle water footprint on livestock sustainability

Abstract Anticipated growth in the demand for beef products driven by increased protein consumption, brings into question the efficiency, sustainability, profitability, and social dimensions of water use for U.S. beef production. Current assessment of U.S. beef production provides a wide range (695 to 14,191 L H2O/kg) of water footprint (WF) measurements of green (rainfed), blue (ground or surface), and grey (waste treatment) water use, but lacks defined region-specific estimates. The objective of this ongoing study is to develop a dynamic mathematical model for Texas beef cattle WF (TXWFB) that allows users to estimate a Texas WF, evaluate assumptions and parameters of current WF methodologies, identify water-use inefficiencies, and provide policy recommendations for a sustainable WF. The TXWFB was developed using Vensim DSS™ and evaluated with the Model Evaluation System™. The TXWFB model correctly replicated the previously published Chapagain and Hoekstra (2003; CH2003) water footprint results for beef cattle with a 36-month lifespan in both grazing [11,915 m3/t (0.4 t)] and industrial beef cattle [9636 m3/t (0.545 t)] systems. Then, parameters (diet composition and water footprints) from the CH2003 model were used as inputs into the TXWFB model to develop baseline scenarios for Texas, using ten climate regions (36-month lifespan; baseline grazing µ = 26,389 m3/t and industrial µ = 24,615 m3/t). The baseline results were then compared to grazing and industrial scenarios with regionalized Texas parameters for pasture, forage, and crop production (evapotranspiration, drought), diet/phase/region (cow-calf, stocker, and feedlot; 24 months). The TXWFB predictions for regional grazing (µ = 7,591 m3/t) and industrial (µ = 5,948 m3/t) results were 71 to 75% less than the baseline scenarios (P < 0.05). We concluded that the TXWFB estimates were considerably smaller than those previously published, suggesting that current WF methodologies can be refined to more adequately assess beef cattle WF in the US.

66 Future-proofing the feedyard workforce: Survey of Texas beef cattle stockpeople indicates positive attitudes towards animals and the workplace while highlighting opportunities for improvement

Abstract A survey was administered to Texas cattle feedyard employees (n = 111) from 31 different operations measuring stockperson perception, job satisfaction, and socioeconomic status using Likert statements and multiple-choice questions. Differences among employment roles (manager, pen rider, processor, doctor) were evaluated using a Kruskal-Wallis test followed by a Multiple Comparison procedure. Managers more strongly agreed that “beef cattle are not dirty” than doctors (P = 0.03) and that “cattle behavior is affected by the way we treat them” than pen riders (P = 0.002) or processors (P = 0.01). Managers were less likely than doctors, pen riders and processors to believe they have too many cattle to look after (P = 0.05, P = 0.006 and P = 0.01, respectively). Pen riders reported less confidence in performing euthanasia than doctors (P = 0.02) and managers (P = 0.02), and, along with processors, agreed that cattle were not always euthanized in a timely manner (P = 0.02 and P = 0.02, respectively). While all roles viewed Holstein cattle unfavorably (P < 0.001), processors viewed them more positively than pen riders (P = 0.05) and managers (P = 0.001). Socioeconomic results showed that Texas feedyards have a dedicated, passionate workforce, with 43% of participants having worked in the industry for 9+ years and 49% of participants working at cattle feedyards because they enjoy working with animals. Unfortunately, it was evident that stockpeople are underpaid (57% of participants making between $10–15/hr) and overworked (76% of participants working 50+ hrs/wk). Survey responses identified critical role-dependent knowledge gaps and biases. A disconnect was observed among compensation, workload, and the duration of time stockpeople spend interacting with cattle. Increasing industry investment in feedyard employees and providing breed-specific and employee role-specific education may promote an encouraging workplace that ensures cattle experience good welfare.

15 Future-proofing the feedyard workforce: Survey of Texas beef cattle stockpeople indicates positive attitudes towards animals and the workplace while highlighting opportunities for improvement

Abstract A survey was administered to Texas cattle feedyard employees (n = 111) from 31 different operations measuring stockperson perception, job satisfaction and socioeconomic status using Likert statements and multiple-choice questions. Differences among employment roles (manager, pen rider, processor, doctor) were evaluated using a Kruskal-Wallis test followed by a Multiple Comparison procedure. Managers more strongly agreed that “beef cattle are not dirty” than doctors (P = 0.03) and that “cattle behavior is affected by the way we treat them” than pen riders (P = 0.002) or processors (P = 0.01). Managers were less likely than doctors, pen riders, and processors to believe they have too many cattle to look after (P = 0.05, P = 0.006 and P = 0.01, respectively). Pen riders reported less confidence in performing euthanasia than doctors (P = 0.02) and managers (P = 0.02), and, along with processors, agreed that cattle were not always euthanized in a timely manner (P = 0.02 and P = 0.02, respectively). While all roles viewed Holstein cattle unfavorably (P < 0.001), processors viewed them more positively than pen riders (P = 0.05) and managers (P = 0.001). Socioeconomic results showed that Texas feedyards have a dedicated, passionate work force, with 43% of participants having worked in the industry for 9+ years and 49% of participants working at cattle feedyards because they enjoy working with animals. Unfortunately, it was evident that stockpeople are underpaid (57% of participants making between $10–15/hr) and overworked (76% of participants working 50+ hrs/wk). Survey responses identified critical role-dependent knowledge gaps and biases. A disconnect was observed among compensation, workload, and the duration of time stockpeople spend interacting with cattle. Increasing industry investment in feedyard employees and providing breed-specific and employee role-specific education may promote an encouraging workplace that ensures cattle experience good welfare.

Process-Based Modeling of Ammonia and Nitrous Oxide Emissions from Open-Lot Beef and Dairy Facilities

Abstract. Airborne emissions, such as ammonia (NH3) and nitrous oxide (N2O), vary considerably among open-lot beef and dairy operations as influenced by climate and manure pack conditions. Because of the challenges with direct measurement, process-based modeling is a recommended approach for estimating airborne emissions from animal feeding operations, such as open lots. The Integrated Farm System Model (IFSM), a whole-farm simulation model for crop, dairy, and beef operations, was previously used (ver. 4.0) to simulate NH3 emissions from open lots and performed well in representing emissions for two beef cattle feedyards in Texas. However, the previous model was found to perform poorly in predicting NH3 emissions measured at two open-lot dairies in Idaho, so further work was done to better represent the effects of climate on lot and manure pack conditions and to integrate better models for nitrification and denitrification processes. The revised model (ver. 4.1) appropriately predicted NH3 emissions for the two Texas beef cattle feedyards, with model predictions having 59% and 81% agreement with measured daily emissions at each lot. Compared to the previous version, the revised model performed better in simulating NH3 emissions for the Idaho open-lot dairies, with 56% to 74% agreement between predicted and measured daily NH3 emissions. For an Idaho dairy with a freestall barn and open lot, the revised model simulated NH3 emissions with 92% agreement between predicted and measured values. Based on measurements obtained at two of the Idaho dairies, IFSM also predicted daily N2O emissions with good agreement (64% to 80%) to measured values. Hence, IFSM can be used to estimate open-lot emissions of NH3 and N2O along with other aspects of performance, environmental impact, and economics of cattle feeding operations in different climatic regions. The model provides a tool for evaluating management strategies to mitigate emissions and improve the sustainability of beef and dairy production systems.

Factors Influencing the Adoption of Water Quality Best Management Practices by Texas Beef Cattle Producers

Factors Influencing the Adoption of Water Quality Best Management Practices by Texas Beef Cattle Producers

Familial and herd-level associations with paratuberculosis enzyme-linked immunosorbent assay status in beef cattle1

A cross-sectional study was performed to determine the odds of having a positive paratuberculosis ELISA result if the dam was ELISA positive in Texas beef cattle, adjusted for individual and herd-level risk factors for seropositivity. Texas beef cattle (n = 2,621) were tested for paratuberculosis by using a commercial ELISA and microbiologic culture of feces for Mycobacterium avium subsp. paratuberculosis (MAP). Pedigree data were collected to identify dam-and sire-offspring pairs. Bayesian mixed-effects logistic regression was used to estimate the odds of seropositivity associated with age, dam ELISA status, sire ELISA status, herd size, herd history of clinical paratuberculosis, within-herd seroprevalence, within-herd fecal MAP prevalence, and within-herd fecal non-MAP Mycobacterium spp. prevalence. Herd of residence was included as a random effect to account for the correlation of observations within the same herd. Statistically probable associations were observed between ELISA status and herd fecal MAP prevalence [OR (odds ratio) 1.28 per 1% increase; P < 0.001] and herd seroprevalence (OR 1.21 per 1% increase; P < 0.001). The association with dam ELISA status was small (OR 1.35) and not highly probable (P = 0.69). Results indicate that use of dam ELISA status to make culling decisions in beef cattle may not improve the success of paratuberculosis control programs. Alternative strategies may be more effective for reducing the odds of seropositivity.

Assessing familial aggregation of paratuberculosis in beef cattle of unknown pedigree

The objective of this study was to assess genetic similarity of beef cattle using microsatellite markers and to use this information to describe familial aggregation of paratuberculosis test results in Texas beef cattle. Paratuberculosis testing was performed on 2622 adult beef cattle using two commercially available serum ELISAs and radiometric fecal culture. Pedigree records were collected for registered purebred herds and herds with sufficiently detailed production records to identify parent-offspring pairs. Cases were defined as cattle with at least one positive paratuberculosis test result. Three controls were matched by herd of residence for each case. All parent-offspring pairs, cases, and controls were genotyped for 12 microsatellites. Bayesian analysis of allele frequency data was used to describe population substructure and assign individual cattle into groups of genetically similar cattle. The proportion of known parent-offspring pairs assigned to the same cluster was used to assess the validity of the approach to identify familial structure. Conditional logistic regression was used to describe the association between cluster assignment and paratuberculosis test-status matched by herd. Nine clusters of genetically similar individuals were identified and were supported by the proportion of parent-offspring pairs assigned to the same clusters. Increased odds of having at least one positive paratuberculosis test result were identified for two clusters compared to the cluster with the lowest proportion of positive paratuberculosis test results after conditioning on herd. The results of this study demonstrate that population substructure can be used to describe familial aggregation of paratuberculosis test results in beef cattle of unknown pedigree.

Improving Profitability in East Texas Beef Herds

Texas Beef Partnership in Extension Program utilized a team approach to recommend sound production and financial practices to improve the profitability of an East Texas beef ranch. The team gathered production and financial information annually, evaluated this data in a standardized information system, set production and financial goals, and developed plans to attain these goals. This systematic process identified management practices that lead to improving profitability in beef herds.

Veterinary Consulting Opportunities Utilizing the Beef PEP Approach

Veterinary/county extension agent teams of the Texas Beef Partnership in Extension Program supported by faculty members from Texas A&amp;M University provide consultation services to six beef cow/calf study herds that subsequently improved their profitability by reducing the cost of producing a hundred-weight of calf. There were six steps to the process: 1) select a herd with a high potential to improve profits, 2) identify opportunities for changes in ranch management practices that will result in improved profitability, 3) develop a ranch management plan, 4) implement the ranch management plan, 5) monitor production and economic outcomes and 6) revise and update the herd plan. Standardized Performance Analysis (SPA) of the study herds’ production levels and economic outcomes was involved in nearly every step and was the foundation of the project. The knowledge base of veterinary practitioners on beef herd health and production coupled with their ongoing contact and high rapport with producers make them the best choice for leadership of successful consultation teams for beef cow/calf operations.

Ranch-management factors associated with antibody seropositivity for Neospora caninum in consignments of beef calves in Texas, USA

A study was conducted with a 1998 retained-ownership population of Texas (USA) beef calves to determine the ranch-management practices associated with calf seroprevalence to Neospora caninum. Management practices of 76 Texas ranches that consigned 760 calves to a retained-ownership feedlot program were reviewed from a mailed questionnaire. Ninety-nine of 760 (13%; 95% CI, 9.4%, 17.7%) calves were positive to N. caninum and 59% of the ranches consigned at least one positive calf. In the logistic multiple-regression model which controlled for overdispersion, increased odds of calf-level seropositivity was associated with seasonal calving patterns, with stocking>1 cow/ calf unit /2.2 ha , using a round-bale feeder, allowing wildlife access to the weaning supplement, and self-reared replacement heifers. However, decreased odds of seropositivity was associated with using a cattle-working dog and with using a self-contained cattle feeder. There was substantial overdispersion due to ranch.

Ranch Management Factors Associated with Seroprevalence of Neospora caninum Beef Calves

A study was conducted with a retained-ownership population of Texas beef calves to determine ranch management practices associated with calf seroprevalence to Neospora caninum.

Estimated production and economic losses from Neospora caninum infection in Texas beef herds

A computerized spreadsheet was used to model economic losses attributed to changes in production parameters for a typical 42 head Texas beef herd following a simulated N. caninum infection. Texas beef herds that completed Standardized Performance Analysis (SPA) records between 1991-1997 supplied the representative production information for economic analysis. SPA production parameters that were used included pregnancy percentage, calving percentage (live calves born), calf death loss between birth and weaning (%), weaned calf crop (%), pounds of calf weaned per female exposed to bulls at start of breeding season, and replacement percentage. The prevalence of N. caninum across and within herds, the risk of increased abortions and stillbirths in infected cows, and the percentage of aborting cows that were culled were collectively superimposed onto the production information in the model either as static estimates (deterministic model) or changing estimates (stochastic model) to cause change in production parameters. Using a deterministic approach and compared to a non-infected herd, a herd with a 20% prevalence of infection experienced an estimated 2.4% lower calving percentage and an overall estimated 2.3% lower weaned calf crop. Estimated weaned calf weight per exposed female was 12.3 lb (5.6 kg) less in an infected herd. Predicted economic loss was $13.75 per head ($577.50 herd loss). Using software that facilitated stochastic modelling, average predicted loss was between $23.29 per head ($978.18 herd loss) and $35.21 per head ($1478.82 herd loss). The total predicted economic loss to the Texas beef industry from this disease was estimated to be $7.6 million using the deterministic economic model. When prevalence figures were allowed to vary, the most likely financial losses to the Texas beef industry were predicted to be between $15 million and $24 million.

Review: Women of the Range: Women's Roles in the Texas Beef Cattle Industry, by Elizabeth Maret

Review: <i>Women of the Range: Women's Roles in the Texas Beef Cattle Industry</i>, by Elizabeth Maret