Master of Science / Department of Animal Sciences and Industry / Jeffrey S. Stevenson / We hypothesized that administration of human chorionic gonadotropin (hCG) to recipients at embryo transfer (ET) would induce accessory corpora lutea (CL), increase circulating progesterone concentrations, and reduce early embryonic loss. At three locations, purebred and crossbred Angus, Simmental, and Hereford recipients (n = 719) were assigned alternately to receive i.m. 1,000 IU hCG or 1 ml saline (control) at ET. Fresh or frozen-thawed embryos were transferred on d 5.5 to 8.5 (median = d 7) of the estrous cycle to recipients having a palpable CL. Recipients received a body condition score (BCS) at ET. Pregnancy diagnoses occurred by transrectal ultrasonography 28 to 39 d (median = d 35) and reconfirmed 58 to 77 d (median = d 67) post-estrus. At one location (n = 108), ovaries were examined to count the number of CL at pregnancy diagnosis. More (P < 0.001) pregnant hCG-treated cows (69.0%) had multiple CL than pregnant controls (0%). Serum progesterone (ng/mL) determined at two locations (n=471) at both pregnancy diagnoses in pregnant cows was greater (P ≤ 0.05) after hCG treatment than in controls (first: 8.1 ± 0.9 vs. 6.1 ± 0.8; second: 8.8 ± 0.9 vs. 6.6 ± 0.7), respectively. Transfer pregnancy rates were analyzed using logistic regression. Unadjusted pregnancy rates at the first diagnosis was 61.8 vs. 53.9% for hCG vs. controls. At the second diagnosis, pregnancy rates were 59.0 vs. 51.4%, respectively. Factors affecting pregnancy rates were treatment (P = 0.03), embryo type (P = 0.02), and BCS (P = 0.08). Odds ratios indicated that greater pregnancy rates occurred in recipients receiving hCG treatment, receiving a fresh embryo (66.3 vs.55.5%), and when BCS >5 vs. ≤5 (62.3 vs. 55.3%). We concluded that hCG at ET increased incidence of accessory CL, increased progesterone in pregnant recipients, and increased transfer pregnancy rates.

Master of Science / Department of Animal Sciences and Industry / J. Ernest Minton / Mitchell Ricketts / Cattle and other livestock have been identified as leading sources of injuries to workers in agriculture. Cattle handling injuries can be serious and often appear to be under-reported [superscript]3,[superscript]4. Many of these injuries involve predictable patterns of interactions among victims, animals, and fixed farmstead structures or gates. There has been some progress toward developing safer facility designs and work procedures, but continuing reports of injuries suggest further efforts are still needed. The present study focused on worker injuries that involved the interaction of three elements: (a) cattle, (b) cattle handlers, and (c) farm structures or equipment—including swinging gates and stationary barriers. The goal of the study was to identify opportunities for injury prevention. The source of injury cases was the Consumer Product Safety Commission’s National Electronic Injury Surveillance System (NEISS)[superscript]29,[superscript]45. We believe this is the first report of cattle related injuries based on NEISS data. We selected the NEISS database for this investigation because it includes product codes for many farmstead barriers such as fences, walls, and doors. The database was also selected because it contains brief narratives that help to describe the circumstances of each incident. Predictable interactions between humans, animals, and farm structures led to many of the cattle handling injuries reported in the NEISS database. In almost 30% of cases, cattle pushed workers into structures such as fences, gates, posts, and walls. In another 16-19% of injuries, cattle struck gates and other objects, propelling them at the victims. These percentages are similar to findings reported in previous studies that drew on data from New York hospitals[superscript]10, news reports in the central United States[superscript]5, and workers compensation cases in Colorado[superscript]3,[superscript]4. In all, gates and other physical barriers contributed to about 45% of cattle handling injuries in the present study.

Master of Science / Department of Clinical Sciences / Bob L. Larson / The 2007 NAHMS (National Animal Health Monitoring System) survey indicated that early lactation health issues are major factors influencing reproduction and culling on U.S. dairy herds. The objective of this study was to evaluate fresh-cow health during the first 30 days in milk, and its association with days to pregnancy in the concurrent lactation. Data were collected on cattle that calved over a two month period (July and August 2009) on a dairy farm located in the Upper Midwest region of the U.S. Health and production data were collected daily for each cow from the beginning of lactation until the majority of the study population was confirmed pregnant. Both a competing risk analysis and a semi-parametric Cox regression model were used to test the association between specific health-related events and days to pregnancy and the outcomes of the two models were compared. These analyses showed metritis and dystocia in the first 30 days of lactation were associated with greater days to pregnancy. The only difference noted between parities was that lactation-five and greater cows were significantly associated with greater days to pregnancy. The two analyses showed conflicting significance of association between retained placenta, ketosis, twinning, lameness, and other non-specific illnesses with days to pregnancy. This study found that a competing risk analysis and a semi-parametric regression model were appropriate methods to analyze time sensitive data such as reproductive efficiency. This study supports the evidence that parity, metritis, retained placenta, ketosis, dystocia, twinning, lameness, and other non-specific illnesses can have an impact on reproductive efficiency.

Master of Science / Department of Grain Science and Industry / J.M. Faubion / The market for frozen goods is expanding and the frozen dough goods sector still has potential to expand its market. It is well known that deterioration in bread quality occurs during frozen dough/bread production. In addition, it is known that dough rheology influences bread quality. To prevent deterioration of bread quality, many additives have been used and researched. Combinations of oxidants (potassium bromate and ascorbic acid) are widely used worldwide. However, potassium bromate may be carcinogenic to humans, and it has been detected in bread after baking. Since it has been prohibited or strictly limited in many countries, many researchers have tried to find a replacement. Ascorbic acid is safe for human intake, and does not persist in bread. However, it is not as effective as potassium bromate. Possible replacements in frozen doughs include oxidant (ascorbic acid)-enzyme combinations. This study evaluated the effects of ascorbic acid-specific enzyme combinations as a replacement for the potassium bromate in frozen dough and related the effects to dough behavior (gluten network strength) as evaluated by dynamic oscillation rheometry. Bread quality was evaluated by test baking. Based on the results from fresh baking studies, potassium bromate can be replaced by an optimum level combination of ascorbic acid and hemicellulase/endo-xylanase. This combination clearly improved loaf volume, and crumb grain over both control and potassium bromate containing doughs. For frozen dough/bread production, the addition of all additives improved bread quality, but ascorbic acid and endo-xylanase containing dough resulted in higher volume, and better crumb structure than did dough containing potassium bromate. Dough rheology experiments show that rheology was affected by both the process and additives. Strain sweeps gave the information about dough stability. Both the additives and proofing improved dough stability. Dough behavior (gluten network strength) was assessed by frequency sweeps. Dough containing ascorbic acid and endoxylanase was most stable during frozen dough processing.

Doctor of Philosophy / Department of Grain Science / Bhadriraju Subramanyam / Mark E. Casada / In commercial grain elevators and feed mills, the boot and pit areas contribute to commingling of insects with grain that moves through the elevator leg. A pilot-scale bucket elevator leg with a modified removable boot, or slip-boot, was used to measure the magnitude of commingling as a function of stored-product insect density and boot holding time in tests with wheat and corn. Pilot-scale tests showed that clean grain transferred over infested boots was infested with about 1 insect/kg when transferred immediately after the boot was infested; this increased to 2 insects/kg after incubating the boot for 8 wk. Larger numbers of kernels with internal infestations were picked up by clean grain during transfer compared with externally infesting insects, because the mobility of the latter enabled them to move away from buckets during transfer. Monthly surveys over two years at elevators and feed mills revealed several stored-product insects in grain residues from the boot and pit areas and bulk load-out samples. Insect densities in the boot and pit areas were impacted by seasonal temperatures and facility sanitation practices. Recommended sanitation guidelines for the boot and pit areas include: (1) boot residual grain clean-out every 30 d, (2) removal of grain spillage and floor sweepings from the pit area, and (3) proper disposal of boot and pit residual grain. Facilities following these sanitation guidelines could avoid costly grain discounts, increase income of the business operation and minimize or prevent cross contamination of clean grain by infested grain in the boot and pit areas.

Master of Science / Department of Agricultural Economics / Timothy Dalton / Previous research on small-scale farmers in KwaZulu-Natal, South Africa indicates that certain genetically modified maize seed types improve production efficiencies and increase net returns (Regier 2012). Yet despite the substantiated advantages, not all farmers have adopted genetically modified maize. The purpose of this research is to identify the determinants of adopting certain types of genetically modified maize over traditional or conventional hybrid maize for 184 small-holders in two villages in KwaZulu-Natal, South Africa. Previous adoption studies use socioeconomic characteristics of the farmer as well as farm-level production characteristics to determine the probability that a farmer will implement an improved agricultural technology. While many studies employ a binomial approach to adoption, this study tests the probability of adopting three different GM varieties—the insect resistant Bt maize, the herbicide tolerant Roundup Ready® maize, and the stacked trait BR maize. Furthermore, the model is enhanced by farmers’ open-ended explanations of their perceptions on genetically modified maize and of the major production constraints they face. Following results from previous adoption studies, this research tests three hypotheses in a three different model structures. The first hypothesis tests whether farmers are more likely to adopt if they have greater financial means to cover higher expected production costs. This is tested by variables measuring off-farm employment and expected production costs. The second hypothesis tests whether farmers with less labor availability are more likely to choose maize with the herbicide tolerant technology, either the Roundup Ready® or stacked BR maize, which reduce the need for weeding. The final hypothesis is whether there are differences in the determinants of adoption that differentiate GM adopters into three distinct categories. These hypotheses are tested in three model structures that test the binary probability of adopting GM maize over non-GM, the probabilities of adopting each maize variety separately, and the intensity of adoption. The first finding is that many non-adopters have greater access to income and are more likely to sell a portion of their yield than are many farmers who adopted, especially in comparison to those who plant RR maize. Also, BR farmers are more likely to report input expenses as a major constraint in their adoption decision. Results for the second hypothesis show that those who planted either RR or BR maize did in fact have less family labor available, used less total labor, and used a greater proportion of family to hired labor. Finally, there are differences in the determinants for geographic site, education, self-sufficiency in maize supply, number of family members working off-farm, and whether households planned to sell any of their maize yields. This indicates that adoption should be considered according to each genetically modified trait.

Master of Science / Department of Agricultural Economics / Kevin Dhuyvetter / Land accounts for more than 75% of a farm operation’s total assets and thus knowledge of land values are very important to landowners. However, many other parties, including lenders, appraisers, investors, and researchers also have significant interest in land markets. Over the past few decades, land prices in Kansas have increased significantly for many different reasons. The main objective of this research is to estimate the impact of various factors on Kansas land values using a hedonic regression model. In cooperation with the Property Valuation Department (PVD) of the Kansas Department of Revenue, farmland market transactions from 1986 to 2009 were obtained for this study. Hedonic models were estimated using Ordinary Least Squares to determine the impact of interest rates, urban areas, location, parcel size, and income on nominal and real Kansas land values. The estimated nominal and real models explained 24.1% and 17.2% of the variation in land prices, respectively, and the results from this study are generally consistent with previous research. This research went further into investigating the relationship between PVD data and United States Department of Agriculture (USDA) surveyed data. Results from this study indicate that USDA surveys significantly underestimate the true market for land prices across Kansas.

Master of Science / Department of Agricultural Economics / Hikaru Hanawa Peterson / Over the past few decades, the prevalence of obesity and diet-related diseases has steadily increased and become a major public health concern. Part of the problem has been attributed to the large quantity of unhealthy (energy-dense) foods U.S. consumers include in their diets. Statistics on food environment suggest that some areas and households have easier access to fast food restaurants and convenience stores but limited access to supermarkets. Limited access to nutritious food and relatively easier access to less nutritious food have been shown to lead to poor diets and, ultimately, to obesity and diet-related diseases. These issues may more negatively affect some communities than others, particularly rural communities as they tend to be further away from food outlets compared to urban areas. Counties are classified as food deserts based upon the percentage of residents living below the federal poverty line and the percentage of residents residing more than one mile from a supermarket. This definition excludes many viable food outlet options, including smaller independently-owned groceries. With rural residents being at a greater disadvantage, it becomes important to consider smaller groceries as an alternative for these communities. The level of social capital may be an indicator of an area’s willingness to support its community. The social environment of rural communities can be characterized as having a high degree of interconnectedness within the community, so that “everybody knows everybody else” (Beggs, Haines, & Hurlbert, 1996). This unique social network in rural communities facilitates the buildup of social capital, which incorporates reciprocity and the willingness to do things for members within the network. This study finds a negative relationship between obesity and social capital in nonmetropolitan counties, as well as a negative relationship between obesity rates and rural grocery stores. These conclusions lend insight into ways to decrease the level of obesity in rural areas.

Master of Science / Department of Plant Pathology / Megan Kennelly / Dollar spot disease of turfgrass, caused by the fungus Sclerotinia homoeocarpa, is the most economically important disease of intensively managed turfgrass such as creeping bentgrass (Agrostis stolonifera) in golf course fairways and putting greens. While several cultural management practices can lessen the severity of the disease, fungicide applications are necessary to manage the disease to acceptable levels. Host resistance is another avenue of improving the quality of turfgrass in response to dollar spot disease, but more information on cultivar susceptibility levels is necessary. Many fungicides are available to control dollar spot, but S. homoeocarpa has shown resistance to both demethylation inhibitor (DMI) and benzimidazole class fungicides. The objectives of this thesis were: (1) to evaluate 15 cultivars of creeping bentgrass under putting green and fairway management for both overall quality and disease severity of dollar spot in the presence and absence of fungicide applications; (2) to determine the sensitivity of Kansas S. homoeocarpa isolates to the DMI fungicides propiconazole, metconazole, tebuconazole, and triticonazole using in vitro mycelia growth assays; (3 to determine a best discriminatory dose concentration for each DMI fungicide that will provide for rapid testing of relative sensitivity, and (4) to sequence the entire β-tubulin gene of several resistant and sensitive isolates to determine mutations associated with resistance. There were differences in turfgrass quality among the 15 cultivars at putting green height but not fairway height. There were no significant differences in disease. In the fungicide resistance assays, the mean EC50 values were 0.0163, 0.038, 0.0612, and 0.0994 µg/ml for metconazole, propiconazole, tebuconazole, and triticonazole, respectively. Correlations were significant and positive for all pairwise comparisons of log10EC50 values. Regressions using discriminatory concentrations tested were significant. The most predictive concentrations were 0.01, 0.05, 0.05, and 0.10 µg/ml a.i, for metconazole, propiconazole, tebuconazole, and triticonazole, respectively. The entire β-tubulin gene was sequenced for four resistant and four sensitive isolates. The resistant isolates all harbored a substitution of alanine for glutamic acid at codon 198 (E198A).

Master of Science / Department of Agricultural Economics / Kevin Dhuyvetter / This research analyzes how crop farms can achieve a higher net income per acre than other operations by farming fundamentally differently than others. There are many factors that are important to the long-term viability of today’s crop operations, one of which is how farms profitability compares with other operations. This determines farms’ ability to compete for land, outlast other operations through periods of unprofitability, and produce crops at long run equilibrium prices. These factors are relevant in today’s crop production industry where farms sit on a segment of the agribusiness supply chain. Therefore, in the interest of providing farms relevant information to manage their operations, this research analyzes how farms can distinguish their performance from other operations by accessing land and equipment resources, production practices for growing crops, and focusing their management efforts differently than other operations. There are three parts to this analysis. First, farms are broken down by characteristics, practices, and management performances. Then an econometric analysis quantifies the integrated correlation between farms’ distinguished characteristics, practices, and management performances and their distinguished net incomes per acre. Next a standard deviation analysis measures the degree to which farms are capable of distinguishing particular characteristics, practices, and management performances from other operations. Lastly, the performance of farms over the 2001 to 2010 time period is used to quantify how feasible it is for farms to maintain particular differences from other operations. Data used in this analysis were provided by the Kansas Farm Management Association, Kansas State University’s Department of Agricultural Economics, and Kansas’s National Agricultural Statistics Service office. The results suggest the way farms distinguish their characteristics, practices, and management performances from other operations impacts how their net income compares to other operations. The econometric analysis found that relative farm size, share of rented acres, the value of overhead and equipment investment per acre, government payments, planting intensity, risk, and cost, yield, and price management performances were all significantly related to farms’ relative net income. In regards to farms’ comparative profitability, this suggests farms should be aware of how their characteristics, practices, and management performances compare to other operations. The results also suggest the degree to which and the consistency with which farms can distinguish particular characteristics, practices, and management performances are different from one another. Over the 2001 to 2010 period, Kansas farms distinguished their characteristics from other operations to a larger degree than they distinguished their practices and management performances. Farms also maintained differences in their characteristics more consistently than they maintained differences in their practices and management performances. This suggests farms that are actively seeking to distinguish their net income per acre from other operations should be aware of the degree and consistency with which they can maintain particular differences from other operations.