Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in beef cattle. Common management practices in addition to BRD have been shown previously to cause inflammation. The objectives of this study were: (1) characterize the inflammatory profiles as indicated by interleukin-1 beta (IL-1β) and haptoglobin concentrations; (2) evaluate the impact of on-arrival metaphylactic antimicrobial therapy on inflammatory profiles in high risk cattle; and (3) examine the relationship between inflammatory profile and BRD morbidity and mortality. Eighty sale barn heifers were purchased over a two-year period (n=160). At arrival, heifers were randomly assigned to either receive tulathromycin (Draxxin, META, n=40) or not (NO META, n=40). Inflammatory profiles remained increased for all groups through d70 (P = 0.028). Metaphylaxis did not affect haptoglobin concentration (P > 0.10). There was a significant increase in BRD cases from day 0 to 20 (P = 0.002). Morbidity (BRD vs no BRD) did not impact haptoglobin concentrations.

The study objective was to evaluate the effects of vaccination (respiratory and clostridial vaccination or no vaccination) and deworming (fenbendazole and levamisole or no deworming) of high risk stocker calves on-arrival on health and growth performance. Eighty sale barn origin calves were purchased three separate years (n=240) from local order buyer. Steers (n=61) and bulls (n=179) were received over three days (d -3 to -1). On d 0 calves were stratified by arrival BW and FEC into 20 pens of 4 calves each, and treatment was applied to pens in 2 x 2 factorial. Vaccination increased the likelihood of BRD 1.7 times (P=0.07) versus calves not vaccinated. Vaccination did not affect gain, but calves receiving dewormer had greater ADG than those not receiving dewormer. Calves that arrived uncastrated or with high fever (≥40.0°C) gained less and were 1.7 and 4.3 times more likely (P<0.10) to be treated for disease, respectively.

Master of Science / Department of Agricultural Economics / Glynn Tonsor / Accessing new management information is crucial for the effective management of an operation in any industry. Beef producers are no exception to this as producers are exposed to numerous risks. The use and implementation of new management information by producers can assist in managing the operation to limit a producer’s risk exposure. The beef industry in the United States today is comprised of a large number of small producers, and operations can be categorized into three segments - cow-calf, stocker/backgrounder and feedlot. Identifying and understanding the characteristics of beef producers assists in the effective design, development, and delivery of educational materials and new information. In 2008, a National Stocker Survey was conducted to collect data from producers nationwide on operation characteristics and production practices as they related to the stocking and backgrounding of calves. The survey was comprised of 10 areas which focused on all aspects of production during the stocker phase. Included in the survey was a section on communication and education, where producers were asked to indicate their level of trust for the 14 sources and 11 methods where by management information might be accessed. The primary objective of this thesis is to identify specific producer and operation characteristics that are key drivers of producer trust for a number of sources and methods where producers may access management information. The factor analysis procedure was utilized to determine the underlying common factors which represented the sources and methods that are used to access management information. Multivariate tobit regression analysis was used to determine the influence producer, operation, and management characteristics had on trust for the underlying factors which represent the sources and methods of information. Summary statistics from this research provide relevant information and show the average level of trust survey respondents have in the sources and methods included. While the models were unable to identify key producer, operation, and management characteristics that are significant drivers of trust, the results of these models do provide insights that may be useful in guiding future research. Producer trust for a number of the sources and methods will likely continue to shift as new technology continues to be integrated into the beef operations and new information is discovered.

Master of Science / Department of Agricultural Economics / Glynn Tonsor / Stocker cattle economic research is very limited in scope. A focus of this research is to deepen our understanding of how cattle price and animal performance variability is viewed and approached by stocker cattle producers in the United States. Another part of this research focuses on what characteristics may be drivers of whether producers choose to practice different risk management strategies. To analyze how cattle price and animal performance variability is viewed and approached by stocker cattle producers, a stated preference valuation method was used to find willingness-to-pay (WTP) estimates. Two different approaches were used to provide outcome probability information where one approach had probabilities for expected ADG change across scenarios and ADG ranges were held constant (Treatment Group A) and the second approach had ADG ranges change across scenarios and the probabilities were held constant (Treatment B). The results of our study suggest that survey respondents process scenarios differently when presented in formats Treatment Group A versus Treatment Group B. The underlying reason for this is beyond identification in this study as respondent certainty and comfort as assessed in follow-up questions was similar across the treatments. Results indicate that producers value buying cattle versus opting out of purchasing cattle and they value higher performing cattle; however, each additional pound is not valued the same. To determine the characteristics of producers and their operations that use different risk management practices, we estimated multiple probit models with the dependent variables being use of the different risk management practices. Results from the probit models suggest how producers source cattle for their operation, whether it is the region or the different markets they source from, are key determinants on whether producers practice different management strategies for market and price risk. The results suggest the model were not a good fit. Of the 30 explanatory variables included in the model, on average five explanatory variables were significant throughout the seven different dependent variables. This could be attributed to factors our study does not explicitly observe; therefore it remains a knowledge gap for the industry.

Master of Science / Department of Animal Sciences and Industry / Dale A. Blasi / Four pen studies and one digestibility trial were conducted to evaluate the effects of energy level and intake of corn by-product based diets on newly received growing cattle. In Exp.1 there were four diets where one was offered for ad libitum intake and formulated to supply 0.99 Mcal NEg/kg DM (0.99/100) and the other three treatments were fed at 95, 90, and 85% of the ad libitum treatment and to supply 1.10 (1.10/95), 1.21 (1.21/90), and 1.32 Mcal NEg/kg DM (1.32/85), respectively. ADG was unaffected by treatment (P = 0.32). However, G:F increased linearly with increasing energy and decreasing intake level (P < 0.01). In Exp. 2, a digestibility trial was conducted to study diets from Exp. 1. Ruminal propionate linearly increased with increasing dietary energy and decreasing intake (P < 0.01). Total tract DM digestibility increased linearly with increasing energy and decreasing intake (P < 0.01), whereas passage rate decreased (P < 0.01). Experiment 3 validated results from Exp. 1 feeding the 1.10/95 treatment at 2.40% of BW daily and the 1.32/85 treatment at 2.2% of BW daily and studied a DNA-immunostimulant (Zelnate, Bayer Animal Health, Shawnee Mission, KS). Zelnate had no effect on parameters measured. ADG was not different between energy treatments (P = 0.75), but efficiency was greater for the 1.32/85 treatment (P = 0.03). Experiment 4 was designed to observe effects of the 1.32 Mcal NEg/kg DM diet fed at four intake levels of 1.9, 2.2, 2.5, and 2.8 % of BW daily. ADG increased linearly with increasing intake (P < 0.01), however G:F was not affected (P = 0.98). In Exp. 5 a factorial design was employed to evaluate the effects of two by-products; wet corn gluten feed and wet distiller’s grains plus solubles, and two levels of corn processing; whole corn or dry-rolled corn. Final ADG and G:F were not affected by by-product, corn processing, or their interaction (P > 0.30). Additionally, animals and diets from Exp. 1 were used to study effects on antibody production, acute phase protein response, stress, and immunocompetency of healthy and morbid cattle. Diet had no effect on the parameters measured (P > 0.10). A quadratic response to time (P < 0.01) was detected for haptoglobin, titers for bovine viral diarrhea type 1 (BVD-1), and infectious bovine rhinotracheitis (IBR). Haptoglobin was highest on d 14, and close to baseline levels by d 27. Titer levels for BVD-1 and IBR were higher on d 14, and significantly higher on d 27. Titers for bovine viral diarrhea type 2 (BVD- II) responded linearly (P < 0.05) to time with the highest levels on d 27. Haptoglobin was elevated in morbid animals compared to healthy pen mates (P < 0.05). Titer levels for BVD-I and IBR were higher in healthy animals (P < 0.01). Fecal cortisol was higher on arrival than on d 14 (P < 0.05). In summary, high-energy limit-fed diets based on corn by-products do not affect health and are more efficient than when roughage-based growing diets are fed.

Master of Science / Department of Agricultural Economics / Glynn Tonsor / The purpose of our analysis was to examine production strategies in the backgrounder and stocker segments of the beef industry within the Flint Hills region of Kansas. The time period analyzed encompassed 1996-2015. September and November placements of steers in the backgrounding sector of the industry were analyzed with an intended March sale date. Placements considered included 425, 500, and 575 pound steers. April and May placements of steers were analyzed for the industry’s stocking sector with an intended July sale date. Placements considered included 450, 600, and 750 pound steers. Within our analysis historical ex-post net incomes were analyzed, prediction errors were calculated (net income, revenue, and cost of gain), and market incentives/signals were analyzed. While for our historical ex-post net income analysis we did not identify one of the four placement strategies as superior in all 20 years of our analysis, we did find scenarios that were typically superior to others. In terms of backgrounding, November placements were typically superior to September placements, in terms of stocking April placements were typically superior to May placements, and when comparing backgrounding and stocking scenarios stocking scenarios were typically superior. In terms of prediction errors, we found that revenue errors are the main drivers of net income error. In general, within the backgrounding scenarios typical producers who are representative of our model assumptions generally overestimate net incomes which is detrimental to them (make lower profits than they anticipate making), while in stocking scenarios producers underestimate net incomes which is generally beneficial to them (make larger profits than they anticipate making). Market signal/incentive and ex-post net income analysis both indicated that steer weight at time of sale was a large factor influencing backgrounder profitability and decision making, and that pasture rents were a large factor influencing stocker profitability and decision making. In all four scenarios it proved economically beneficial to place lighter steer rather than heavy steers. Further research may include, but is not limited to; adding bulls and heifers to our model, analyzing different placement weights within our model, and allowing for animal performance variability within our model.

The objectives of this study were to evaluate the effect of number of stocker cattle in receiving pens (large: n=150 cattle; small: n=50 cattle) on 1) BRD morbidity/mortality, and performance, 2) antimicrobial use and prevalence of antimicrobial resistance in Mannheimia haemolytica, and 3) profitability of stocker operations. No differences were found for morbidity (p=0.5041). Mortality tended (p=0.0744) to be higher in large groups. BW increased (p LESS THAN 0.0001) over time. A treatment*day interaction (p=0.00592) was found for ADG, with largest gains for both groups from day 14-28. M. haemolytica recovery decreased (p=0.0002) over time. Antimicrobial resistance (p=0.0179) and MDR (p=0.0405) were higher in the small group. Treatment costs were higher in the small group ($1,093.53/hd) compared to large ($1,037.04/hd). Because of the nature of a pilot study, further research are needed to determine the effectiveness of reducing animals in a pen on health, growth, AMR, and profitability associated with stocker cattle.