Theses and Dissertations at Montana State University (MSU)
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Item The use of nuclear magnetic resonance spectroscopy and measures of cattle temperament to predict feedlot perfromance of commercial beef cattle(Montana State University - Bozeman, College of Agriculture, 2021) Bouffiou, Jesse James; Chairperson, Graduate Committee: Jennifer ThomsonThe objective of this study was to identify small molecule metabolites in a serum sample taken at entry into the feedlot that can predict performance, and animal health. One-hundred and thirty-one Angus x Simmental steers from a single ranch were sampled at a commercial feedlot. Blood samples for metabolite analysis, chute score, exit velocity, and blood lactate concentration for temperament classification were collected in addition to feedlot performance data and carcass quality measurements. The GLM and LSM procedures of SAS were used to evaluate differences between temperament classifications. Steers were divided into three exit velocity classifications with fast animals having exit velocity greater than one standard deviation from the mean and slow animals having exit velocities lower than one standard deviation from the mean. Forty metabolites were quantified using 1H NMR Spectroscopy from serum. Metaboanalyst was used to analyze serum metabolites and phenotypic values using one way- ANOVA, PCA, PLS-DA, and a permutation test to cross validate. Data was normalized and scaled. No metabolites were predictive of any of the animal health metrics collected. Five metabolites were different in exit velocity class at p < 0.01 (methanol, isopropanol, lactate, isobutyrate, and pyruvate). Similarly, 7 metabolites were different between chute score classes at p < 0.01 (methanol, isobutyrate, creatinine, dimethyl sulfone, hippurate, isopropanol, and succinate). Furthermore, several metabolites in serum at entry in the feedlot were related to carcass quality metrics: back fat (urea and 2-hydroxyisobutyrate at p < 0.01), a trend for prediction of quality grade at p = 0.068, carcass value p = 0.085. The relationship between serum metabolites, feedlot performance traits, and eventual carcass quality warrants further research to elucidate the roles these metabolites play during the feedlot period and in predicting carcass merit.Item Surgency: a holistic model(Montana State University - Bozeman, College of Letters & Science, 2017) Canen, Mara June; Chairperson, Graduate Committee: Rebecca BrookerPrevious examinations of the temperamental trait surgency have largely focused on single facets of the global construct rather than attempting to identify how- or if- individual facets truly converge to comprise a global trait. The current project tested a holistic model of surgency based on temperament theory (Rothbart & Derryberry, 1981) that used a multi-trait multimethod approach to integrate multiple domains of regulation and reacitivity. Four models were tested that included measures of physiological regulation, behavioral regulation, emotion regulation, and parent-reported temperament. A single model emerged that accounted for biological, behavioral, affective, and parent-reported, domains of surgency in 3.5 year old children. This model comprised high levels of positive affect, fidgeting, impulsivity, and RSA suppression loading onto a single latent factor of high surgency. This work contributes to the temperament literature by providing initial evidence for a holistic composite of surgency during early childhood that is consistent with classic temperament definitions of surgency.Item The evocative effect of children's physiologocial stress reactivity on intrusive parenting(Montana State University - Bozeman, College of Letters & Science, 2017) Najjar, Reema; Chairperson, Graduate Committee: Rebecca BrookerSelf-regulatory processes, such as effortful control, are important facets of development for children's long term adjustment. Effortful control is known to be influenced by biological processes that enable regulatory function. Specifically, better biological regulation is associated with better effortful control. The direction of environmental effects, however, is less clear. Although theoretical perspectives support the possibility that parent-child influences are bidirectional, studies of self-regulation -- both physiological regulation and effortful control -- have almost exclusively focused on a parent-to-child direction of effects. Almost no research has investigated the influence of children's physiological and behavioral regulation on parenting behaviors. My thesis explored one process by which physiological regulation, indexed through measures of neuroendocrine reactivity, and behavioral regulation, indexed as effortful control, may evoke intrusive behaviors in parents. I hypothesized that greater cortisol reactivity would predict lower levels of effortful control, which would subsequently predict greater intrusive parenting. I tested my hypothesis in a sample of preschool-aged children and their parents, capitalizing on a critical period for the development of self-regulation. Results indicate that cortisol reactivity did not work through effortful control to predict parent intrusiveness. However, effortful control did moderate the association between child cortisol reactivity and parent intrusiveness. Specifically, when children were high in effortful control, greater cortisol reactivity predicted greater intrusive parenting. This work sheds light the importance of considering bidirectional effects in the development of self-regulation in early childhood.Item Relationship between current temperament measures and physiological responses to handling of feedlot cattle(Montana State University - Bozeman, College of Agriculture, 2015) Williams, Andrew Fillmore; Chairperson, Graduate Committee: Jane A. BolesTemperament in beef cattle has become a research focus due to increasing consumer awareness of animal welfare. Researchers have defined temperament as behavioral responses to a perceived stressful event. "Fight-or-Flight" response is influenced by environmental and genetic factors including age, sex, and breed. Subjective chute scoring systems have been used by many researchers. Due to the subjectivity and associated variability among observers, chute scores have been questioned for repeatability and consistency. An alternative measurement currently used, is exit velocity or speed at which an animal exits a chute, and is recognized as the most practical objective measure for assessing temperament. Physiological markers used to evaluate temperament are increased blood cortisol and lactate concentrations. The first objective of this study was to compare temperament differences between feedlot steers and heifers. The second objective was to evaluate physiological measures taken chute side as potential markers for defining an animal's temperament and potential predictor. Pulse, oxygen saturation, rectal temperature, blood lactate, blood glucose and lactate concentrations, salivary cortisol, and serum cortisol were measured on mixed breed and sex feedlot cattle (n = 197), significant difference alpha = P< 0.05 . Exit velocities were used to classify animals as fast, medium, and slow, plasma lactate was significantly different between all classes. Exit velocity and physiological measures differed between sex. Heifers had higher exit velocities (P = 0.003), plasma lactate concentrations (p = 0.03), and cortisol concentrations (P = 0.001). Simple correlations among these variables showed rectal temperature (heifers r = 0.44, P <0.0001; steers 0.45 P < .0001), plasma lactate (heifers r = 0.52 P < 0.0001; steers r = 0.63 P < 0.0001), serum lactate (heifers r = 0.53 P < 0.001; steers r = 0.59 P < 0.001) and glucose (heifers r = 0.54 P < 0.001; steers r = 0.32 P <0.003) were all correlated to exit velocity in both sexes. Cortisol measures were not correlated to exit velocity in steers but were in heifers. Linear models were constructed and evaluated using Akaike information criterion, the top candidate model was plasma lactate in combination with body temperature to predict exit velocity.Item The relationship between temperament type and motivations of Gallatin County 4-H volunteers for recruitment and retention efforts(Montana State University - Bozeman, College of Agriculture, 2015) McRae-Holland, Christina Maree; Chairperson, Graduate Committee: Carl IgoThe researcher examined 4-H adult volunteers using both the Real Colors TM temperament instrument and an instrument based on McClelland's trichotomy of needs. Volunteer personality temperaments and motivations had been observed in previous studies as defining factors for both recruitment and retention. However, no studies pertaining to 4-H volunteers had been conducted to determine if temperament type was a predictor for motivations. The researcher collected data from 16 current Gallatin County 4-H volunteers with at least one year of volunteer experience. Results revealed that the blue (idealist) temperament type was the dominant temperament type among the participants and orange (artisan) as the least dominant. Volunteers with blue (idealist) temperament types identified affiliation as their preferred motivation type, and orange (artisan) temperament identified achievement. Motivational statements identified as most and least important were included. No statistically significant correlation existed between temperament types and motivation subgroups (affiliation, achievement, and power). The study outlined motivation statements of importance for the different color temperament types and made recommendations for broader recruitment and retention strategies for a more adaptive volunteer program.Item Effect of temperament and growth rate on tenderness of beef steaks from Simmental cross steers(Montana State University - Bozeman, College of Agriculture, 2013) Kohlbeck, Katelyn Storey; Chairperson, Graduate Committee: Jane A. BolesTenderness has been identified as one of the most important traits consumers think about when choosing a steak. Unfortunately, the variation and lack of tenderness in steaks has created a negative eating experience for consumers. Recent research has raised the question if temperament as measured by exit velocity and docility scores could be a factor influencing variation in tenderness. However, docility scores are applied subjectively and exit velocity measurements require timers that can be expensive. An objective score that could be used would be helpful. Animals under stress often revert to anaerobic metabolism, especially in the muscle. Anaerobic metabolism results in elevated blood lactate suggesting the use of the small blood lactate meters as objective measures in identifying an animal's response to stress. The objective of this study is to determine if temperament effects growth rate and overall tenderness of beef steaks, and can blood lactate be used as an objective measurement of temperament. One hundred and fifty four steers were evaluated for exit velocity, blood lactate and docility score. Steers were humanely harvested and carcass data obtained. Loins from 30 steers were obtained and cut into steaks. The steaks were aged 3,7,14, and 21 days postmortem and used for shear force, and myofibrillar fragmentation index analysis. All temperament measurements were significantly correlated meaning if average lactate measurement went up the exit speed was high along with the docility score being higher. Temperament and growth classification significantly affected carcass weight. The animals that left the chute more slowly had lower carcass weights than did the steers that left the chute at a fast or medium rate. Additionally, blood lactate significantly affected shear values. Shear was significantly correlated to growth rate, along with blood lactate level. In conclusion temperament did not affect growth rate but did have an impact on tenderness. Our results suggest that growth rate, exit velocity and blood lactate contribute to variation in tenderness. Finally, if an animal is temperamental based on exit scores and lactate concentrations before harvest this could set the stage for postmortem processes that contribute to the high variance in tenderness in the marketplace.