Oklahoma State Research Articles

Increasing Black Employees’ Social Identity Affirmation and Organizational Involvement: Reducing Social Uncertainty Through Organizational and Individual Strategies

Despite the psychological benefits of authenticity, Black employees within predominantly White organizations often face the dilemma of whether to downplay versus highlight their social identity. Our research introduces social uncertainty as a unifying lens to understand the reluctance of these employees to express their social identity. Highlighting the central role of social uncertainty also helps identify novel factors at both the organizational level (authenticity climates) and individual level (perspective-taking) that can encourage Black employees to engage in social identity affirmation—authentic expressions of the positive aspects of their social identity. To test our hypotheses, we conducted two survey studies, two experiments, qualitative interviews, as well as coded text responses to our experimental prompts. Across our studies, authenticity climates were associated with greater social identity affirmation by Black employees, and this relationship was strengthened when these employees engaged in perspective-taking. Consistent with our theorizing, social certainty mediated these direct and moderated effects. In addition, social identity affirmation increased Black employees’ organizational involvement. Our experimental studies offer causal evidence for the roles of both authenticity climates and Black employees’ perspective-taking, our qualitative interviews vividly illuminate our hypotheses, and our text response analyses provide insight into how authenticity climates operate. Overall, the current research highlights how organizations can help Black employees feel comfortable emphasizing and expressing their true selves by increasing their social certainty. These findings also have direct implications for organizational leaders, providing them with actionable strategies to create more inclusive environments. Funding: The research was supported by Northwestern University and Oklahoma State University. Supplemental Material: The online appendix is available at https://doi.org/10.1287/orsc.2020.14659 .

First Report of Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae) in Oklahoma.

The corn leafhopper, Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae), is an invasive insect that can cause damage to maize (Zea mays L.) in two ways: by direct feeding and the transmission of several plant pathogens. Dalbulus maidis is an invasive and serious economic pest of maize that has spread from its center of origin in Mexico to the southernmost parts of the United States. Prior to 2024, corn leafhoppers had not been documented in Oklahoma, and their spread northward toward the United States corn belt is of significant concern. Here, we provide the first reports of the insect in maize in several Oklahoma counties. Insect specimens were collected at various commercial and experimental field sites by Oklahoma State University research and extension personnel. The identity of the insect species was validated through morphological and molecular taxonomy. The presence records for the corn leafhopper presented here provide valuable information for future monitoring and management efforts of this economically important pest and disease.

Instructor Gender Influences Non-Major’s Drawings of an Entomologist

The Draw-a-Scientist Test (DAST) has been extensively researched as a projective test used to assess individuals’ perceptions of scientists. This study investigated student perceptions of entomologists and compared responses of students taught by a male instructor with responses of students who viewed video lectures recorded by the male instructor but interacted with a female instructor. Data were collected from two sections of an introductory entomology course at Oklahoma State University, with one section taught by a male instructor and the other by a female instructor using lecture recordings of the male instructor. Drawings were analyzed for characteristics including facial expression, clothing, equipment, presence of insects, race, and gender. The majority of drawings included smiling faces, glasses, and entomology equipment, while few students illustrated persons of color. Specific criteria to classify drawn entomologists as male, female, or non-gender figures were developed and used to assess drawings. The majority of students in both sections drew male entomologists, consistent with previous DAST studies where male scientists predominate. However, a higher proportion of female entomologists were depicted in the section who interacted with the female instructor. These findings emphasize the impact of instructor gender on students’ perceptions and stereotypes. Even when lectures are given by a male instructor, interaction with a female instructor can positively influence the gender representation in students’ drawings. Efforts should be made to promote diversity and inclusivity in instruction to increase underrepresented groups in science. This study contributes criteria to assess student depictions of gender and provides valuable insights into the gender representation and characteristics depicted in student drawings of entomologists. It highlights the influence of instructor gender on students’ perceptions and stereotypes in entomology and likely applies to other fields of biology.

High-Altitude Inflatable Kites and Their Role in Atmospheric Boundary Layer Research

AbstractKites have been used as weather sensing solutions for over 250 years. The fact that they are simpler to operate and train on than alternative aerial systems, their ability to keep station at a fixed point for a long term, simplified altitude control, and the ease of retrieving their payload attribute to their growing appeal in atmospheric research. NASA, Toyota, and the School of Mechanical and Aerospace Engineering Oklahoma State University are active in developing and deploying high-altitude inflatable kite systems for atmospheric boundary layer (ABL) research—crucial to advancing the accuracy of weather forecasting. Improvements in kite design, as well as instrumentation and supporting infrastructure, are key to further accelerating the use of kites in atmospheric research. The work underway by these researchers is intended to be a deliberate step in the evolutionary development of these beneficial systems.

Judge rules in favor of former graduate assistant

Case name: Swank v. State of Oklahoma, No. CIV‐24‐102 (E.D. Okla. 07/12/24).

Judge rules in favor of former graduate assistant

Case name: Swank v. State of Oklahoma, No. CIV‐24‐102 (E.D. Okla. 07/12/24).

Exploring the social acceptability of hybrid sweetgum plantations in the south-central United States

Hybrid sweetgum has potential as a dual-purpose plantation in the southern United States due to its rapid growth and suitability for planting on a wide range of sites. To understand its social acceptability, a survey instrument was administered among 3,000 private landowners in the states of Texas, Oklahoma, Louisiana, and Arkansas. The survey results showed that a considerable percentage of landowners (41 %) were uncertain and would probably benefit from more information available to them on the topic. A multinomial logit analysis found that landowners who had timber management objectives were more interested in growing hybrid sweetgum if it was profitable and practically feasible. Similarly, female landowners and those having higher education were found to be more interested in growing hybrid sweetgum. Study findings suggest a need for outreach on economic feasibility, management, start-up costs, and tax implications concerning hybrid sweetgum plantations.

Max-convolution processes with random shape indicator kernels

In this paper, we introduce a new class of models for spatial data obtained from max-convolution processes based on indicator kernels with random shape. We show that these models have appealing dependence properties including tail dependence at short distances and independence at long distances. We further consider max-convolutions between such processes and processes with tail independence, in order to separately control the bulk and tail dependence behaviors, and to increase flexibility of the model at longer distances, in particular, to capture intermediate tail dependence. We show how parameters can be estimated using a weighted pairwise likelihood approach, and we conduct an extensive simulation study to show that the proposed inference approach is feasible in relatively high dimensions and it yields accurate parameter estimates in most cases. We apply the proposed methodology to analyze daily temperature maxima measured at 100 monitoring stations in the state of Oklahoma, US. Our results indicate that our proposed model provides a good fit to the data, and that it captures both the bulk and the tail dependence structures accurately.

Hydro‐modeling the ecosystem impact of wastewater reuse under climate change: A case study in upper Red River basin, Oklahoma

AbstractWater reuse, as a viable option for water supply, must be implemented to minimize the adverse impacts on stream ecosystems that previously received this wastewater effluent. In the State of Oklahoma (OK), USA, local communities have implemented wastewater reuse, and many seek to expand the reuse programs. This study presents a hydro‐modeling analysis based on the Coupled Routing and Excess STorage with VECtor routing (CREST‐VEC) model focusing on the potential ecosystem impacts and societal benefits of wastewater reuse under climate change in the OK portion of the Red River basin. First, a CREST‐VEC model is established for the upper Red River basin and validated against observed streamflow for a 30‐year historical period (1990–2020). Based on the established model, we then assess the sensitivity of ecosystem impact to various climate change scenarios and hypothetical wastewater reuse scenarios. Results show that dominant effects of climate change cause the annual time below environmental flow to increase in the next 30 years, which constrains the room to implement wastewater reuse. However, at sub‐catchment scale, the analyses identify viable locations for allocating wastewater reuse while maintaining ecosystem health. The results also reveal that wastewater reuse brings about the most societal water benefits at minimal cost of ecosystem health under representative concentration pathway (RCP) 2.6 followed by RCP 4.5 and then RCP 8.5. Overall, the study demonstrates capabilities of the hydro‐modeling framework in developing water management plans facing the changing climate.

Phenology of five tick species in the central Great Plains

The states of Kansas and Oklahoma, in the central Great Plains, lie at the western periphery of the geographic distributions of several tick species. As the focus of most research on ticks and tick-borne diseases has been on Lyme disease which commonly occurs in areas to the north and east, the ticks of this region have seen little research attention. Here, we report on the phenology and activity patterns shown by tick species observed at 10 sites across the two states and explore factors associated with abundance of all and life specific individuals of the dominant species. Ticks were collected in 2020–2022 using dragging, flagging and carbon-dioxide trapping techniques, designed to detect questing ticks. The dominant species was A. americanum (24098, 97%) followed by Dermacentor variabilis (370, 2%), D. albipictus (271, 1%), Ixodes scapularis (91, <1%) and A. maculatum (38, <1%). Amblyomma americanum, A. maculatum and D. variabilis were active in Spring and Summer, while D. albipictus and I. scapularis were active in Fall and Winter. Factors associated with numbers of individuals of A. americanum included day of year, habitat, and latitude. Similar associations were observed when abundance was examined by life-stage. Overall, the picture is one of broadly distributed tick species that shows seasonal limitations in the timing of their questing activity.

PSIV-A-13 The relationship between breed-wide expected progeny differences, genomic predictors, and phenotypic values in mature Angus cows

Abstract For many years, selection for improved beef production centered on heavier weaning weights and more rapid post-weaning gain. More recently, measurement of post-weaning feed intake has facilitated direct improvement in feed efficiency in the feedlot. However, intake on a high concentrate diet is controlled by different biological mechanisms than intake on a high roughage diet. For this reason, the question remains whether an animal that efficiently converts calories from a high-quality concentrate-based ration similar to that of a feedlot diet where the expected progeny differences (EPDs) and genomic predictors (GPs) are developed would also be an efficient forage utilizer as a mature cow. To evaluate this relationship, we compared breed-wide EPDs and predictors to performance on a roughage diet and on a concentrate diet in mature cows. The objective of this study was to determine if EPDs and GPs developed and used in feedlots are applicable to commercial cow/calf producers utilizing forages and other roughages as the main diet ingredient. Data for this study were collected at Oklahoma State University from the fall of 2018 to the spring of 2021. Tissue samples from 64 mature Angus cows were submitted to Neogen for profiling according to genetic potential for 16 different traits. In each trial, retained energy (RE), dry matter intake (DMI), milk production (MILK), mature weight (MW), and average daily gain (ADG) were recorded and compared with the corresponding EPD and GP. Pearson correlations were determined between phenotypic values, GPs, and EPDs for both diets on each trial. No EPD or GP was significantly correlated to any measured trait on the forage diet. The DMI EPD was strongly correlated with DMI on a concentrate-based diet, however, did not predict DMI on a forage diet in mature cows. Based on the evaluations performed in this study, selecting for animals that perform well in the feedlot may be inadvertently selecting for mature cows that perform poorly on a typical mature cow diet of medium to low-quality forages.

First report of the Horse nettle virus infecting tomato (Solanum lycopersicum L.) in the United States.

Tomato (Solanum lycopersicum L.), a member of the Solanaceae family, represents one of the most extensively cultivated vegetable species worldwide and traces its origin to western South America (Caruso et al. 2022). In a field survey conducted in 2023 in Bixby, Tulsa County, Oklahoma, distinct symptoms were noted in two plants: one exhibited mottling and cupping of leaves and brown discoloration on leaves, petioles, and stems, while the other displayed a downward curling of leaves. Leaf samples from both symptomatic tomato plants (labelled as K4 and K5) were collected, and total RNA was extracted individually via the TRI Reagent® method (Molecular Research Center Inc., Cincinnati, OH, USA). Subsequently, the RNA samples were pooled and subjected to high-throughput sequencing (HTS) on the NextSeq 500/550 high-output kit v2.5 (Illumina, U.S.A.) at the genomic facility, Oklahoma State University (Stillwater, OK). Total read count of 8,227,020 (average length =150.5 bp) was obtained, trimmed, and de novo assembled using CLC Genomics Workbench v22.0.1 (QIAGEN) and used for BLASTn and BLASTx analysis. Two contigs: 6,375 bp (average coverage 2,915.92, read count 142,538) and 3,564 bp (average coverage 3,035.91, read count 82,370) from the pooled sample showed 88.6% and 96.7% nucleotide identities with RNA 1 (OP292294) and RNA 2 (OP292295) of Horse nettle virus A (HNA-A) isolate MD-1, respectively. Sequences of both partial contigs (RNA 1, accession no. PP063196) and RNA 2, accession no. PP063197) were submitted to GenBank. The HTS data did not reveal any other viral or viroid sequences in these two tomato samples. To further confirm the presence of HNV-A, total RNA from K4 and K5 samples was tested individually by RT-PCR using HNV specific primers (Supplementary Table 1) based on the two partial contig sequences. The expected PCR products (491 bp and 451 bp) were obtained only from the K4 sample and none from the K5 sample. PCR products were extracted from an agarose gel, cloned into the pGEM®-T Easy vector (Promega), and transformed into Escherichia coli DH5α cells (New England Bio Labs). Two clones for each PCR product were sequenced by Sanger sequencing. Nucleotide sequence comparisons and BLASTn analysis of 491 bp and 451 bp showed 86% and 97% nucleotide identity with RNA 1 and RNA 2 of HNV-A isolate MD-1 (OP292294 and OP292295), respectively. Additionally, eight more leaf samples from eight different symptomatic tomato plants were collected in the same field and tested by RT-PCR as described above. All eight samples were positive by RT-PCR, but no PCR band was obtained in the total RNA from a healthy tomato leaf used as a control. Sequences from the PCR products were identical to the obtained HTS sequences. Our results confirmed for the first time that HNV-A can infect tomatoes. Currently, HNV-A has been reported to only infect a single weed (Horse nettle, Solanum carolinense) (Zhou et al. 2023). The identification of HNV-A in tomatoes in Oklahoma suggests a potential host shift is of concern for local growers as well as tomato growers worldwide. This shift underscores the urgency for an in-depth investigation into the transmission and host specificity of HNV-A. This is the first report in the United States and the world that HNV-A could infect tomatoes naturally in a grower field.

Characterization of genetic diversity of greens‐type hybrid bermudagrass selections through SSR markers and morphological analysis

AbstractThe development of Tifgreen bermudagrass, and the subsequent mutations of this cultivar, has revolutionized the game of golf in the southern United States as superintendents have access to high‐quality putting surface capable of withstanding hot summers. However, the lack of genetic diversity may make them vulnerable to various pests and the low tolerance to freeze temperatures may make them susceptible to winterkill. In recent years, Oklahoma State University and other universities have begun to create new interspecific F1 hybrids between common (Cynodon dactylon) and African bermudagrasses (C. transvaalensis) for putting greens. The objectives of this study were to investigate the genetic diversity and variation among 14 experimental genotypes and two standard cultivars (TifEagle and Tifdwarf). Simple sequence repeat (SSR) markers and morphological characteristics were used to evaluate the genetic relationships and variation among the 16 genotypes. Results showed significant variation for 11 vegetative traits and two reproductive traits. The phenotypic coefficient of variation was greatest for the third internode length and the least for the first leaf angle for both the field and greenhouse trials. The morphological cluster analysis also showed variation between the two trial environments. The SSR marker cluster analysis showed the 16 genotypes were grouped into four major groups, with a similarity coefficient ranging from 0.44 to 1. The highest similarity was found among the two commercial standards and an experimental ultradwarf from Florida. Several new genotypes (OKC3920, 5 × 23, 11 × 2, 19 × 19, and 34 × 20) were also grouped with the ultradwarf genotypes in the morphological cluster analysis, showing the possibility of achieving similar morphological traits with new genetics. Further field evaluations are needed to determine the performance of these genotypes under low mowing heights.

Directional Breeding Generates Distinct Genetic Diversity in Hybrid Turf Bermudagrass as Probed with Simple Sequence Repeat Markers

Bermudagrass (Cynodon spp.) is a drought-resistant warm-season turfgrass adapted to the southern and transitional zones in the United States. Multiple hybrid cultivars have been developed and released for use as turfgrass, and others are still undergoing development. Increasing genetic diversity of commercial cultivars is vital to stress tolerance. A DNA profiling study of 21 experimental selections from the Oklahoma State University turfgrass breeding program and 11 cultivars was conducted using 51 simple sequence repeat primer pairs across the bermudagrass genome. A pairwise genetic relationship analysis of the genotypes using 352 polymorphic bands showed genetic similarity coefficients ranging from 0.59 to 0.89. The average pairwise population differentiation values were 0.012 for the 11 cultivars and 0.169 for the 21 selections. A cluster analysis using the unweighted paired group with the arithmetic average method grouped the entries into six clusters. A correlation analysis identified different levels of pairwise genetic relationships among the entries that largely reflected parental relationship. Directional breeding and selection for cold hardiness or drought resistance created progeny that had distinct genetic diversity in the tested bermudagrasses. It is evident that an increase in genetic diversity of the existing cultivar pool with the release of one or more experimental selections for commercial use will strengthen and improve bermudagrass systems.

Sensitivity of Standardized Precipitation and Evapotranspiration Index (SPEI) to the choice of SPEI probability distribution and evapotranspiration method

Study regionThe state of Oklahoma located in the Southern Plains region of the United States. Study focusThe standardized precipitation evapotranspiration index (SPEI) is a widely used meteorological drought index that incorporates potential evapotranspiration (PET) into a precipitation-based index. However, the understanding of the appropriate PET method for SPEI across different temporal scales in non-arid climate conditions remains limited. We compared Thornthwaite (TW), Hargreaves (HG), and Penman-Monteith (PM) equations for SPEI at various accumulations, considering three temporal scales: 1) long-term (25 years), 2) event-based, and 3) monthly. Also, we examined the log-logistic and generalized extreme value distributions to test the normality of SPEI computed from the three PET methods. To do this, we utilized high-quality climate datasets measured at 107 stations across the state of Oklahoma, United States, which has a diverse climate ranging from semi-arid to humid subtropical. New hydrological insights for the regionThe log-logistic distribution was found to be suitable for SPEI. The SPEI-HG showed better agreement with SPEI-PM than SPEI-TW in this region for the analyses of three temporal scales. However, for accumulations of SPEI longer than one year, both TW and HG equations showed no significant differences with SPEI-PM. The findings provide practical guidance for selecting an appropriate PET equation in the Southern Plains region depending on the purpose of study without resorting to data-intensive methods for PET estimation.

34 A survey of the Oklahoma State University Cowculator user preferences

Abstract The Oklahoma State University Cowculator is a free, easy to use model designed to assist cattle producers in making informed decisions regarding the nutrition of their herd. The Cowculator operates as a spreadsheet-based model, which collects information from the 2016 National Academy of Science, Engineering, and Medicine’s Nutrient Requirements for Beef Cattle, previous editions of the book, and previous research data. Producers have the option to adjust animal characteristics, feed and forage values, and diet composition to fit certain production objectives. In 2022, a Qualtrics survey was developed to determine perception of users of the program and their likes and dislikes. When users download the program, they are required to enter their name, email address, and zip code. A link to the survey was emailed to each address registered within the Cowculator database, with an email reminder sent out 30 days later. The survey yielded 233 responses. According to user download data, in 2022 the Cowculator was downloaded 2,090 times from 41 states and 53 countries. Based on email addresses ending in “.edu” the program was downloaded by faculty or students from 135 different universities, colleges, or other technical institutions. Of the respondents, 60% identified as beef cattle producers, 16% as industry professionals (e.g., consultants, veterinarians), 11% as extension personnel, 7% as research or teaching faculty, and 6% as students. Regarding the type of enterprise which the program was used for, 52% responded with cow/calf, 33% growing or stocker cattle, and 15% finishing cattle. The survey indicated that 88% of respondents were able to utilize the program effectively to evaluate or modify their nutrition program, while 16% indicated they were not successful in using the program. The survey asked respondents to give their opinion on the accuracy of the program. 69% indicated that it yielded “mostly accurate” projections, 23% responded with “very accurate”, and 5% perceived the program to be inaccurate or marginally accurate. Users of the program estimated the average annual benefit of the program to be $1,500. The respondents were asked to select what they liked about the program and what they felt needed improvement. It was indicated that the most liked features were that the program was free and that it was easy to use. The features that were indicated as needing improvement where the limited pre-added list of feedstuffs and the lack of availability of a simplified app version of the program. The results of this survey provide valuable insights regarding user demographics, as well as what can further be adjusted within the Cowculator to best fit the needs of the users.

85 Evaluation of a Saccharomyces cerevisiae fermentation product on performance, plasma metabolites, rumen parameters, and fecal pathogen shedding in feedlot steers

Abstract The objective of the experiment was to evaluate a commercial Saccharomyces cerevisiae fermentation product (SCFP; NaturSafe, Dimond V, Cedar Rapids, IA) on performance, plasma metabolites, rumen parameters, and fecal pathogen shedding in feedlot steers. Crossbred steers (n = 61; 271 ± 48.1 kg) were sourced from 3 different research units at Oklahoma State University and assigned to 1 of 3 experimental treatments in a randomized complete block design. Steers were group housed in pens equipped with an automated individual feed intake system. Treatments consisted of a negative control (CON), CON with tylosin phosphate (TYL; 9.9 mg · kg-1 of diet DM), or CON with SCFP (1.63 g · kg-1 of diet DM). Body weight and feed efficiency did not differ among treatments (P ≥ 0.12). However, steers fed SCFP tended to have greater ADG from d 35 to 56 (P = 0.10). In addition, steers fed SCFP exhibited increased DMI from d 56 to 112 (P = 0.03), a tendency for increased DMI from d 112 to final (P = 0.07), and increased DMI overall (P = 0.05). There was no treatment × time interaction for pH, pH change, or lactate concentrations in rumen fluid (P ≥ 0.11), but all were impacted by time (P < 0.01). A treatment × time interaction (P < 0.01) was detected for fecal pH and fecal pH change, with the pH being greater in TYL fed steers on d 56 and in CON fed steers on the final day. Steers that consumed CON had a reduced fecal pH (P < 0.01) and steers consuming SCFP tended to have a reduced fecal pH (P = 0.08) from d 35 to 56 compared with TYL fed steers, while both CON and SCFP fed steers experienced an increase in fecal pH from d 56 to 112 (P < 0.01). A time effect was detected (P ≤ 0.04) for plasma glucose, lactate, urea nitrogen, and non-esterified fatty acid concentrations among treatment groups. A treatment × time interaction was observed (P < 0.02) for stx2 genes of Shiga toxin producing Escherichia coli (STEC) in individual fecal samples where SCFP and TYL fed steers tended to exhibit an increased concentration compared with CON fed steers on d 14, while on d 190 CON and SCFP fed steers exhibited an increased concentration compared with TYL fed steers. Overall, STEC, E. coli O157:H7, and Salmonella concentrations were all impacted by time (P < 0.001). This experiment suggests that SCFP could be utilized as a potential alternative to TYL in feedlot cattle without adversely affecting cattle performance. However, SCFP did not impact pathogen shedding. In addition, CON fed steers performed similarly to both SCFP and TYL fed steers.

150 Effects of diet type on performance and methane yield in replacement beef heifers

Abstract The objective of this experiment was to determine the relationships among enteric gas production, body weight (BW) gain, and feed intake for growing heifers consuming two energy divergent diets. Fifty-five fall born yearling Angus and Angus cross heifers were used in a 157-d experiment. Heifers were fed two consecutive diets at the Oklahoma State University Range Cow Research Center. Heifers were sorted into one of two drylot pens based on BW. Each drylot pen was equipped with individual intake monitoring system (C-Lock Inc., Rapid City, SD) with a stocking rate of 3.3 heifers per feeder. The first intake segment (HAY) was initiated with a 21 d of adaptation followed by 70 d of data collection. Heifers were offered ad libitum access to long stem unprocessed bermudagrass hay and a salt/mineral/vitamin supplement. After the HAY period, heifers were adapted to a 50% forage, 50% concentrate diet (TMR) during a 14-d adaptation period, followed by 52-d of data collection. Means and standard deviations for phenotypic traits of DMI, ADG, RFI, and CH4 were 6.7 ± 0.7 kg, 0.44 ± 0.13kg, and 194.6 ± 17.56 g/d respectively for HAY and 14.3 ± 1.34 kg, 1.72 ± 0.20 kg, and 280 ± 24.69 g/d respectively for TMR. Pearson correlations between diets for DMI, ADG, and CH4 were 0.32, -0.16, and 0.29, respectively. Coefficient of variation for DMI was 10.8% for HAY and 9.4% for TMR. Coefficient of variation for ADG was 29.9% for HAY and 11.6% for TMR. Methane intensity was calculated as CH4, g/day divided by DMI, kg/d resulting in 29.6 ± 3.5 and 19.9 ± 2.2 g CH4/kg DMI for HAY and TMR, respectively. In summary, HAY DMI was moderately and positively correlated with TMR DMI while ADG was not correlated among the two diet types. The HAY diet generated less total daily CH4, although more CH4 per unit of feed intake.

110 Effects of sire selection on puberty and reproduction of offspring selected as replacement heifers

Abstract Sire selection is important to maintain the desired genetic capability of any cattle herd; therefore, selection of economic production traits affect profitability by increasing pre- and post-weaning gain and carcass quality potential. Using heifers developed from sires selected for growth and milk traits may have long-term impact on sustainability of the cowherd by influencing mature cow size and milk production. Our objective was to determine the impacts of sires selected for high and moderate growth and high and low milk traits on growth and reproductive performance of replacement heifers. Therefore, we selected replacement heifers sired by bulls within the upper 5th and 50th percentiles of the Angus breed for yearling weight (YW) EPD as high growth (HG) moderate growth (MG), the upper 15th percentile of the Angus breed for milk EPD as high milk (HM), and the lower 15th percentile for low milk (LM) in a 2×2 factorial design resulting in 4 treatments: HG/HM, HG/LM, MG/HM, and MG/LM. Heifers (n = 46) from appropriate AI sires that were born and developed at Oklahoma State University – Range Cow Research Center – South Range Unit were selected as replacements. They were raised on a base diet of dry, dormant tall grass prairie and moderate quality grass hay following weaning and 2 kg/d of 16% crude protein concentrate supplement. Body weights and biometrics were recorded at weaning and approximately at 1-yr of age, and blood was collected at 11 and 0 d before synchronization for progesterone analysis to determine pubertal status pre-breeding. Estrus was synchronized using the 14-d CIDR-PG with timed AI method followed by a 45-d natural service breeding period. Pregnancy checks were conducted by serum collection 35-d following AI and via rectal palpation by an experienced veterinarian 112 d after removal of the bulls. Statistical analyses were performed using the mixed procedure of SAS (SAS 9.4, SAS INC., Carey, NC). Heifers from high growth sires were 28 kg heavier at weaning (P < 0.01) and 26 kg heavier as yearlings (P < 0.01) than those sired by moderate growth sires, while sire milk EPD affected neither (P ≥ 0.55). High growth and high milk sired heifers had greater hip heights, frame scores and thus greater (P ≤ 0.05) estimated mature body weight (EMBW). Despite this, sire selection had no impact on percentage of heifers pubertal before breeding, AI pregnancy, or the total pregnancy rates (P > 0.24) Based on these data, selection of sires for HG and HM leads to increased productivity of the offspring but gives rise to larger mature cows, which may pressure grazing resources in limited resource environments impacting the long-term sustainability of the cow-calf enterprise.

Perceived Obstacles in Land Use Change for Hybrid Sweetgum Plantations: Landowner Opinions from the South Central United States

Abstract Hybrid sweetgum (Liquidambar styraciflua × L. formosana) has received considerable attention as a potential feedstock for traditional and nontraditional forest-based enterprises due to its fast growth and large specific gravity. However, the perceptions of landowners are important to understand the degree of acceptance concerning land use change to consider this opportunity in the United States. We administered a survey instrument to three thousand landowners representing the states of Texas, Oklahoma, Louisiana, and Arkansas where hybrid sweetgum plantations would be feasible. A seemingly unrelated regression analysis was used to explore the attributes that may influence the environmental and economic obstacles in land use change for hybrid sweetgum plantations. Study results suggest that landowners who perceived higher importance of marketing aspects of hybrid sweetgum expressed greater economic concerns for land use change. In contrast, those having higher planted pine acres had higher environmental concerns about land use change. Female landowners were more concerned than their male counterparts. Landowners need access to accurate information from their trusted sources to make informed management decisions, especially when making decisions to adopt new opportunities such as hybrid sweetgum. Study Implications: Study results reveal the need for outreach to landowners in the south central United States, as many were not aware of fast-growing hardwood species such as hybrid sweetgum. Information on growth potential, economics, and management techniques can help facilitate the adoption of hybrid sweetgum. Field visits and peer-to-peer learning facilitated by early adopters can be effective strategies for outreach.