The juxtaposition of a forage-fed diet versus a high-energy grain-based diet for beef cattle has become a prevalent issue concerning consumers today. Because the influence of media, and modern culture’s general push for a return to natural and healthy living, people have developed an opposition to the way in which corporations produce the meat we as customers purchase and consume. There is reason to react, but it must be noted that much of the evidence and information made public is not conclusively proven through scientific research, and even still, experimental studies have yet to determine substantial evidence. The primary goal of this proposed experiment is to investigate the correlation between Escherichia coli O157:H7 growth and the diet of beef cattle, focusing on grass-based versus grain-based diets. I would like to investigate this phenomenon further and discover—with the majority of factors thought to foster E. coli O157:H7 growth eliminated (change in environment, feed and feeding method)—whether diet is actually the significant issue promoting the population growth of E. coli O157:H7. The secondary goal of this proposed experiment is to investigate the correlation between diet and the nutritional content of the beef produced. Grass-fed beef has been popularized and marketed as a healthier option to conventionally raised grain-finished beef. It has developed a reputation based on little scientific evidence, so I would like to examine this topic further by issuing nutritional profiles of the beef produced by steers from this study and contribute to the ongoing research. Sixty newborn Angus calves from Hearst Ranch will undergo a 1-2 year study. Groups of steers, differentiated by diet, will be organized using color-coded identification tags that attach to the ears of the steer. Group 1 will consist of 15 steers fed a 100% forage diet based off of the regimen. Group 2 will consist of 15 steers fed a forage diet that is 25% high grain concentrate. Group 3 will consist of 15 steers fed a forage diet that is 50% high grain concentrate. Group 4 will consist of 15 steers fed a forage diet that is 75% high grain concentrate. Monthly rectal swab fecal samples should be collected and assessed according to the procedures of Davis et al. 2005. I hypothesize that E. coli O157:H7 growth will not show statistically significant differences between diets. I do believe population growth will show an increase during summer months as opposed to winter months, however. After steers have reached their optimal weight of 1100-1200 pounds, they will be slaughtered. A USDA professional will grade the carcasses, and further nutritional profiling tests will be done at to University of Georgia Meat Science Technology Center. Proximate, cholesterol, and fatty acid compositions for each of the steers will be profiled according to the procedures of Duckett et al. 2009. I predict that the nutritional profile of the beef produced will show significant differences, where the grass-fed steers will have a much higher concentration of omega 3 fatty acids, vitamins, and minerals.

I conducted 6 years of field work to evaluate the habitat use and population dynamics of an experimental release of elk (Cervus elaphus) into Great Smoky Mountains National Park (Park). Elk exhibited relatively small home ranges (female: 10.4 km2 and males: 22.4 km2) and movement distances decreased over time. I calculated survival rates (x = 0.73–0.93) and litter production rates (x = 0.73) for the population. To assess the potential for a long-term elk population, I incorporated those vital rates into the population modeling software Riskman and tested its sensitivity to any given vital rate. The projected population growth was positive (1.03, SD = 0.001) and the probability of extinction in 100 years was minimal (1%, SD = 0.001). However, the model was sensitive to adult female survival, and the simulated annual deaths of only 4 adult females increased the probability of extinction to 45% (SD = 0.021). Compositional analysis detected a strong preference for grassland areas by elk in the Park. I used spatial data to identify potential habitat for elk on a multivariate level by calculating the Mahalanobis distance (D2) statistic based on the relationship between elk locations and 7 landscape variables. The D2 model indicated that the best elk habitat primarily occurred in areas of moderate landscape complexity and edge denisty and gentle slope, and was limited in the Park. At the current small population density, elk had minimal impact on vegetation inside the Park and their diet consisted primarily of graminoids. The elk population at Great Smoky Mountains National Park will likely remain small and vulnerable to extinction for some time due to low growth rates, high environmental stochasticity, and limited habitat. Active management (e.g. predator management, prescribed burning, and mowing) will be required to maintain this population until the population grows to more sustainable levels.

Several properties within Tennessee were managed under a quality deer management (QDM) philosophy from 1998 to 2006. Harvest characteristics of three private properties and three Wildlife Management Areas (WMAs) were compared to determine effects on buck harvest rates and the age structure and sex ratio of the harvest. Average annual buck harvest decreased at most areas following antler restrictions and ranged from 55 to 68% of pre-QDM levels because younger bucks were protected. Although the raw numbers showed an increase in older-aged bucks harvested following antler restrictions, when calculated on a per hunter or per permit issued basis, statistical increases were not observed at all study areas. Regardless, hunters at each area felt QDM restrictions were working toward their goal and planned to apply to hunt that area the following season. Most hunters regarded themselves “somewhat knowledgeable” with QDM and considered it a sensible management philosophy. The majority of club hunters (55.5%) and plurality of sportsman license holders (36.9%) and WMA hunters (34.7%) favored a statewide limit of two bucks, and the majority of all hunters favored including does in the harvest and protecting young bucks from harvest. The production and nutritional quality of twenty forages used in food plots and the effects of prescribed burning and understory fertilization on browse production in closed-canopy hardwoods one growing season after treatment were also evaluated. Crimson clover and a cool-season grain (wheat or oats) are recommended to address the mid-late winter stress period, and can be planted with arrowleaf clover to further extend forage availability in the spring. Warm-season annual forages (cowpeas, lablab, and soybeans) supplied forage during the late summer stress period when natural forage quality is low. Ladino clover and chicory supplement production gaps of annual forages. Because of variable results among two sites and because the cost per pound of forage produced following fertilization exceeded $26 per pound, understory fertilization and prescribed fire in closed-canopy hardwood stands are not recommended for increased deer browse. Treatments providing increased sunlight through a reduction in percent canopy cover are much more effective and efficient in providing increased browse.

Metacommunity theory has been particularly useful in understanding the way spatially structured communities assemble. Both niche and neutral processes are known to influence metacommunity assembly, and the relative influence of each depends on the level of dispersal-limitation. Contemporary trait-based analyses of metacommunity assembly have enhanced our understanding of these processes. Of the traits investigated, individual personalities have received the least attention, but have been suggested to be drivers of metacommunity assembly model parameters, such as dispersal tendencies and patch density. I address this topic from three angles, three chapters, in this dissertation. First, I used a three-year field survey of fish metacommunity assembly in Everglades National Park to investigate the influence of dispersal-limitation on trait-based metacommunity assembly, asking which traits were important under different levels of dispersal-limitation. I found that the relative influence of traits and local environmental factors decreased, and the influence of regional factors increased with increasing dispersal-limitation. The Rocky Glades has recently been invaded by a micropiscivore with many novel traits, the African Jewelfish. In the second chapter I used my field data to ask what influence this invader has on metacommunity assembly. Overall, African Jewelfish abundance was the third most influential factor in driving assembly. I also used data, which were previously collected by collaborators, from three years prior and two years following the invasion to observe shifts in assembly rules. Assembly became significantly more aggregative immediately following the invasion, a condition which persisted more than a decade later. All previous studies asking the same question, found the same result: invasive introductions correspond with increased species aggregation. This may be a consistent, taxa-independent signal of truly invasive species that can be detected early in the invasion process, making it a potentially useful management tool after further empirical review. In the final chapter, I investigate the potential influence of individual personalities on a metapopulation’s structure. To do this, I used a behavioral individual-based model to explore the influence of sociability, an individual’s propensity to associate with conspecifics, on metapopulation structure at ecologically relevant spatiotemporal scales. I found that individual sociability can significant influence key metapopulation parameters such as dispersal distance and patch density but may not influence landscape occupation. Chapter three concludes with new hypothesis to be evaluated by future field studies. Overall, this dissertation demonstrates the relative roles of invasions, species traits, and individual personalities on metacommunity assembly processes.

ABSTRACT COMPLETION OF AN IN VIVO DIGESTIBILITY TRIAL IN HORSES AND IN VITRO DIGESTIBILITY ASSAY DEVELOPMENT Cassandra Renee Sweeney In vivo analysis of equine feed digestibility has been the gold standard since the late 1800's, although it can be time consuming, costly, and labor intensive. In vitro digestibility analysis may be more economical and beneficial to both feed manufacturers and consumers. The availability of accurate in vivo data is crucial for critical evaluation and validation of any potential in vitro method (Coles et al., 2005). Ten adult American quarter horse geldings were used in the in vivo digestibility evaluation of two complete pelleted feeds fed as 100% of intake. The ingredients of the two treatments were similar: wheat middlings, rice hulls, alfalfa and beet pulp. The treatments differed in added mineral sources, yeast, direct fed microbials, and Yucca schidigera extract, added to enhance dry matter digestibility of the test diet. The in vivo evaluation consisted of two phases in a randomized crossover design. Total daily dry matter intake (DMI) and daily dry matter excretion (DME) were measured. Apparent digestibility (aDig) of % DM, % NDF, % ADF, % ADLom, and % OM (DM) were also calculated. No differences were seen in aDig of NDF, ADF, ADLOM or OM between the two experimental diets (P > 0.05). There was also no difference in DMI or DME, as a percentage of body weight (BW), between the two experimental diets. The effect of phase was not significant for all tests run on aDig, DMI, and DME (P > 0.05). BW was not significantly different (P > 0.05) between diets, however there was a trend for v heavier BW during phase 2 (P = 0.073). In vitro digestibility assay development followed the in vivo evaluation. A three-stage batch system as briefly described by Boisen and Fernandez (1997) was utilized. Through literature review, trial and error, personal communication with other labs and product and chemical manufactures, careful documentation of the methods were detailed. Using the control feed from the in vivo evaluation, variation in the methods was significantly reduced, and estimations of DML began to approach those seen in vivo throughout method development. Although further method development may be needed for species-specific use, the methods described here can provide the foundation for future in vitro digestibility studies.

<p>Developing bat pups produce distinct vocalizations called isolation calls (I‐calls) that serve to attract the bat’s mother. How individual pups shift their vocalizations from I‐calls to downward frequency modulated (FM) sweeps during development remains unclear. By recording individual bat pups from the day of birth to twenty‐five days postnatal we observed behavioural and bioacoustic (temporal and spectral) changes in pup calls. Temporal characteristics examined were call duration and call rate; spectral characteristics were minimum frequency, maximum frequency, peak spectral frequency, total signal bandwidth, maximum frequency of the fundamental acoustic element and bandwidth of the fundamental. I‐calls were produced only until a certain point in development, after which pups change from emitting long‐duration, tonal I‐calls to downward FM signals and eventually short‐duration biosonar vocalizations. We discovered additional spectral changes in the harmonic structure of pup calls, with the number of harmonic elements decreasing with age. We also recorded pup vocalizations during prolonged separation from their mothers to determine if extended isolation alters the type, number or acoustic structure of emitted vocalizations. Rate of calling was influenced by prolonged separation; younger pups had higher calling rates and called longer than older pups. We also compared temporal and spectral characteristics of spontaneous and provoked calls. We found that provoked calls were more similar to vocalizations produced by younger pups. By documenting the vocal behaviour and acoustic structure of pups calling in different situations, this research provides groundwork for further studies on the ontogeny and development of FM vocalizations in bats and other mammals.</p> / Master of Science (MSc)

Sarcopenia is a condition that is most common in aged animals, and is characterized by the loss of skeletal muscle mass and integrity, and can lead to physical disability and poor quality of life. Since skeletal muscle protein synthesis can be limited by the availability of amino acids, supplementation of limiting amino acids to ameliorate the progression of sarcopenia has become a topic of interest in companion animal research. Although there is some data to support the idea that amino acid supplementation improves maintenance of muscle mass in aged horses, the cellular mechanisms behind that improvement have yet to be elucidated. Therefore, the objective of this study was to examine the effect of amino acid supplementation in aged horses on markers of whole body and muscle protein metabolism. In a cross-over design, six old horses were studied while receiving each of three treatments in a replicated Latin square design. For all three treatments, horses received 1.8% BW/d of timothy hay cubes and 0.5% BW/d of experimental concentrate. The three treatments included a control (CON) treatment concentrate that was designed to meet all requirements of mature horses when fed in combination with the timothy hay cubes, and two supplemented concentrates, LYS/THR with additional lysine and threonine (40 mg/kg BW/d and 31 mg/kg BW/d, respectively), and LYS/THR/MET with additional lysine, threonine, and methionine (40 mg/kg BW/d, 31 mg/kg BW/d and 11mg/kg BW/d respectively). In each 15 d period, following a 9-day adaptation, horses were fitted with a collection harness, and total urine and feces were collected for 72 hours for assessment of nitrogen balance and creatinine output. Blood samples were taken directly before feeding and 30, 60, 90, 120, 150, 180, 210, and 240 minutes post-feeding for analysis of plasma urea nitrogen (PUN), glucose, insulin, and plasma amino acid concentrations. Muscle biopsy samples were taken for analysis of proteins in the mTOR pathway. Additionally, horses underwent stable isotope infusion procedures, and comparisons of phenylalanine kinetics were used to determine whole-body rates of protein synthesis and degradation. There was no significant effect of treatment on creatinine output (P=0.58), relative abundance of proteins in the mTOR pathway (P>0.05), nitrogen retention (P=0.70), or phenylalanine kinetics (P>0.05). PUN concentrations were significantly (P=0.0058) higher for LYS/THR and LYS/THR/MET than for CON. Atrogin-1 activation was significantly higher for the pre-feeding CON sample compared to the post-feeding CON sample. Lack of significant difference in creatinine output suggests that there were not significant differences in muscle mass between treatments. Lack of significant differences in mTOR protein activation suggests that amino acid supplementation did not result in improvements in protein synthesis. Lack of significant differences in nitrogen retention and phenylalanine kinetics suggests that whole-body protein metabolism was not improved. Additionally, higher PUN concentrations in the supplemented diets suggests that the supplemented amino acids being provided were catabolized. However, increased activation of Atrogin-1 in the pre-feeding CON samples, but not the pre-feeding samples of supplemented treatments, suggests amino acid supplementation may have reduced protein degradation in the post-absorptive state. Data from the present study suggests that amino acid availability may not have been limiting protein synthesis in the sedentary aged horses in the present study.

The amino acid requirements of growing horses are currently unknown, and studies suggest that threonine is a limiting amino acid in common horse diets. Thus, the objective of this study was to determine the threonine requirement of growing horses fed two different forage to concentrate ratios using the indicator amino acid oxidation method. The study consisted of a high concentrate phase (HC; 60% concentrate and 40% forage) and a high forage phase (HF; 25% concentrate and 75% forage). Within each phase, 6 female yearling Thoroughbred horses were randomly assigned each of 6 dietary treatments in a 6 x 6 Latin square design. All 6 treatments were identical, apart from varying equimolar ratios of threonine to glutamate. After 6 days of adaptation, blood samples were collected before and after the morning meal for plasma urea nitrogen (PUN) and amino acid analysis. On day 7, horses underwent the IAAO protocol, during which regular breath and blood samples were collected. Phenylalanine flux, oxidation, non-oxidative disposal, and release from body protein, as well as total carbon dioxide production were calculated using plateau enrichment of samples. There was a significant linear effect of threonine intake on plasma threonine concentrations, and PUN had a significant linear response during the HC phase. There was no significant effect of treatment on phenylalanine oxidation during either phase (P ≥ 0.05). It is unlikely that threonine was limiting in the experimental diets.

Estradiol (Compudose®, COM) implants are extensively used in beef cattle production systems to alter body composition and feed efficiency. Little information exists about the physiological mechanisms affected by COM treatment in growing, mature, and senescent female cattle. Moreover, no reports describe the level of blood estradiol resulting from COM treatment. The effect of COM on levels of plasma estradiol and blood metabolites and proteins, and relative content of glutamine synthetase (GS) and other amino acid nitrogen-metabolizing enzymes in liver tissue, was studied using three experimental models relevant to cow-calf production regimens: senescent cows (Trial 1), young mature (young) versus senescent (old) cows (Trial 2), and growing heifers (Trial 3). In Trial 1, plasma estradiol concentrations were 222 % more after 14 and 28 d in COM-implanted than sham implanted (Control) cows. COM treatment did not affect measured blood metabolites and enzymes, but increased hepatic GS protein expression by 350% after 14 d and 200% after 28 d of implantation. In contrast, protein expression of alanine transaminase, aspartate transaminase, glutamate dehydrogenase, and two glutamate transporters was not affected by COM. In Trial 2, plasma estradiol concentrations of COM implanted young and old cows were 48% higher than Control groups, whereas blood metabolites were not affected. COM implantation did not affect GS protein expression in young cows, but tended to increase GS expression in the old cows by 283% after 14 d and 41% after 28 d. GS mRNA content was increased about 38% in both young and old COM-treated cows. Hepatic content of beta-catenin and G protein-coupled receptor 30 (GPR30) content was not affected by COM treatment, indicating that estradiol-mediated GS expression was not regulated by beta-catenin- or GPR30-controlled pathways. In Trial 3, plasma estradiol levels in COM-treated heifers were 70% higher in COM heifers, concomitant with increased levels of total bilirubin and creatine kinase, and decreased creatinine. Correlation analysis of plasma estradiol levels and blood constituents only identified a positive correlation between plasma estradiol and potassium. Collectively, these data describe positive estradiol-mediated effects on hepatic metabolism and blood parameters in female cattle.

A contingency analysis of the sequence of actions associated with agonistic behavior of resident and introduced male Sceloporus undulatus nya irthirus was carried out to determine the degree of stereotypy. During the time period April to June 1984 and 1985, caged pairs of adult male and juvenile female lizards were filmed on three occasions in order to gather data on resident males not involved in aggressive interactions. During the same threemonth time period, a different nonresident male was introduced singly into a given resident's cage on three occasions and the interactions filmed. The films were analyzed to determine which actions were agonistic, the sequence of actions and the transition frequencies from one action to another. The sequence of actions was determined to be probabilistic, that is, the occurrence of one action influenced the probability that a specific action would follow. The most probable behavioral sequence for resident males during male-male interactions was head turn-crawl-jaw snap-lateral compression-bobbing-attack. The latter three actions were unique to agonistic encounters. The introduced males expressed a similar behavioral sequence except that they very rarely attacked. The behavioral sequence of resident females during male-male interactions consisted of head turn-crawl-jaw snap-bobbing. Bobbing generally preceded jaw snapping in females when such male-male interactions were not taking place. The probabilistic nature of the display action pattern during agonistic behavior is similar to that observed in other iguanid lizards studied. Three levels of arousal were evident in resident males during aggressive interactions. These were 1) heightened awareness, 2) display and 3) attack. Again, this observation is consistent with those in studies carried out in other iguanid lizards.