A 19.3-km section of U.S. Highway 64 in Washington County, North Carolina was rerouted to a 4-lane, divided highway with 3 wildlife underpasses during 2001–2005. I determined the short-term population and genetic impacts of the new highway on American black bears (Ursus americanus). I used DNA from hair samples collected during 7 weekly sampling periods within the project area of the new highway and a nearby control area during 2000 (pre-construction phase) and 2006 (post-construction phase; n = 70 sites for each study area). DNA from the hair samples was used to obtain genotypes of sampled bears using 10 microsatellite markers. I created capture histories of all identified individuals and used closed mark-recapture models in Program MARK to estimate abundance. Population abundance decreased on the treatment area from 68 (CI = 53–82) before construction to 20 (CI = 14–26) after completion of the highway. On the control area, population abundance decreased from 144 to 101. Using permutation procedures, I determined that the decrease in population abundance on the treatment area was greater compared with the control area (P = 0.0012). Additionally, I used bear visits to the sampling sites with multi-season occupancy models in Program MARK to determine if site occupancy decreased following the construction of the highway and if any decrease was a function of distance from the highway. Following highway construction, site occupancy decreased more on the treatment area than the control area but was not a function of distance from the highway. Finally, I used the microsatellite data to compare gene flow, isolation by distance, heterozygosity, allelic diversity, population assignment, and genetic structure (Fst) before and after completion of the highway. I did not observe any treatment effects for these genetic measures. I speculate that displacement during the construction of the highway and mortality due to bear-vehicle collisions contributed to the population decline and decrease in site occupancy. Although the wildlife underpasses facilitated genetic and demographic connectivity, my study indicates that the potential impact of new highways on black bear population abundance is an important consideration for transportation infrastructure planning.

Global decline of amphibian populations has been linked to various anthropogenic stressors. Recent studies have quantified the influences of cropland agriculture and deforestation; however, few have examined the impacts of allowing cattle access in wetlands on resident amphibians. I compared four wetlands exposed to cattle grazing for >10 years against four wetlands that had not been grazed for >10 years, at the University of Tennessee Plateau Research and Education Center. At each wetland I measured species richness, diversity, and species-specific relative abundance of postmetamorphic amphibians captured in pitfall traps and during breeding call surveys, amphibian egg mass abundance, shoreline vegetation structure, and soil compaction from March – August 2005 and 2006. Pathogen prevalence and histopathological changes were measured from a subsample of opportunistically collected amphibians. Landscape characteristics were quantified and related to amphibian community structure. Relative abundance of green frog metamorphs was 9.8X greater in 2006 and 2.3X greater in 2005 at non-access wetlands. Relative abundance of American toads was 68X and 76X greater at cattle-access wetlands in 2005 and 2006, respectively. Breeding call abundance of American toad, Fowler’s toad, and Cope’s gray treefrog was 4 – 25X greater at cattleaccess wetlands in 2006. There were 2X more spring peepers and pickerel frogs calling at non-access wetlands in 2005 and 2006, respectively. Species richness, diversity, and egg mass abundance were not significantly different between land-use types each year. In general, body size followed a density-dependent relationship across species. Height and percent horizontal and vertical cover of shoreline vegetation were 74%, 25% and 84% greater, respectively, in non-access wetlands in 2005; trends were similar in 2006. Soil compaction was 55% greater at cattle-access wetlands. Pathogen prevalence and histopathological changes did not differ between land uses. Landscape analyses revealed species-specific associations related to wetland isolation and geometric complexity of the landscape between wetlands. My results suggest that cattle influence community composition and postmetamorphic body size of amphibians, but effects are speciesspecific. Differences in postmetamorphic abundance may be related to less vegetation structure and lower water quality at cattle-access wetlands. Fencing cattle from wetlands may be a prudent conservation strategy for some amphibian species.

Prior research in our lab has demonstrated a significant association between the incidence of subclinical mastitis and neutrophil functions with polymorphisms of the CXCR1 gene in Holstein dairy cattle. The objective of this study was to evaluate the specificity of the response relative to CXCR1 and potential involvement of intracellular signaling pathways. Migration was evaluated in cows of both homozygous genotypes (n=7 each) in response to high and low doses of interleukin-8 (IL -8; specific for CXCR1 and CXCR2), epithelial neutrophil activating peptide (ENA-78; specific for CXCR2) or zymosan activated sera (ZAS; complement receptors). Cows with a GG genotype had significantly more migration in response to both 12.5 and 50 nM doses of IL -8 (p<0.05) compared to cows with a CC genotype. Although a similar trend was observed for 50 nMENA-78 (p<0.07), this was not evident with the 12.5 nM dose. This result was comparable to ZAS, where the 5%dose caused significantly more neutrophil migration in cows with a GG genotype than those with a CC genotype (p<0.03), while the response to the 1% dose of ZAS was similar between genotypes. p38 MAPK and PKB phosphorylation were evaluated prior to and following stimulation with the high doses of each ligand. Relative increases in p38 MAPK phosphorylation were greater in neutrophils from cows with a GG genotype when compared to those with a CC genotype regardless of treatment with rhu-IL-8, rhu-ENA-78, and ZAS or not (p<0.001), But CC cows had higher baseline levels of p38-MAPK phosphorylation than GG cows. Therefore, the lower increase in phosphorylation in neutrophils from CC cows may have been due to higher starting levels. Increases in PKB phosphorylation also were greater in neutrophils from cows with a GG genotype when compared to a CC genotype when treated with ZAS, but not other ligands. Because no differences between genotypes were observed at time zero this may be tied to the altered p38 MAPK pathway. Future research will be aimed at further elucidating the signaling pathways causing functional differences in neutrophils from cows with different CXCR1 genotypes.

An 84 d randomized block design using 96 beef calves (238.8 + 20.1 kg) in each of two years was used to assess the efficacy of energy supplementation and glucomannan (MTB) to alleviate tall fescue toxicosis. Groups of four calves were randomly assigned to 24 endophyte-infected tall fescue pastures (1.23 + 0.06 ha). Pastures of calves were randomly assigned to treatments: unsupplemented (CON), supplemented with soybean hulls (SH) at 0.33% BW (DM basis; LO), supplemented with SH at 0.66% BW (DM basis; HI), LO plus 20 g·hd-1·d-1 MTB-100® (LO-MTB), HI plus 20 g·hd-1·d-1 MTB-100® (HI-MTB). Calves were weighed and serum collected every 21 days. Fecal grab samples were taken from d 55 to d 59 and analyzed for dry matter chromium and ergot alkaloid concentrations. Tympanic temperatures were taken from one calf for 3 days each week from d 59 to d 84. Data were analyzed using the MIXED procedure in SAS with contrasts of effects of MTB, level of SH supplementation (LEVEL), MTB x LEVEL interaction, and CON vs. supplemented (SUPP). Treatments differed in ADG (P < 0.01) with LEVEL affecting weight gains (P < 0.01). Supplemented calves had increased weight gains compared to CON (P < 0.01). Supplementation increased gain per hectare (P < 0.01) and was influenced by LEVEL (P < 0.01). Control calves excreted higher concentrations of ergot alkaloids than SUPP (P < 0.01). Forage and total DMI increased as a result of supplementation (P < 0.01). Prolactin levels differed among the treatments on d 63 and 84 (P < 0.01) with increases attributed to LEVEL (P < 0.05). There were differences between CON and SUPP (P < 0.01) on d 63 and 84, where SUPP increased prolactin concentrations to twice that of CON. Tympanic temperatures were similar among treatments (P > 0.05); daily maximum temperatures and diurnal range differed among the treatments (P < 0.01). SUPP animals had lower maximum temperatures and decreased diurnal range compared to CON (P < 0.01). These findings indicate that SH supplementation can lessen the severity of fescue toxicosis; however, glucomannan fed at the current level only affected tympanic temperature.

Two 84-day grazing trials were conducted (Aug 24 – Nov 17, 2006; Jun 14 - Sept 7, 2007) near Spring Hill, TN to determine the efficacy of Endo-Fighter (R), an ADM Alliance Nutrition, Inc. product designed to be fed to cattle grazing or fed endophyte-infected fescue or hay and Prototype, an improved version of Endo-Fighter (R). Tall fescue pastures with >90% of pasture exhibiting infestation (E+), thus producing high concentration of ergot alkaloids in the grass, were grazed. In 2006 sixty weaned crossbred heifers (325 ± 17 kg) (2007, steers, 267 ± 18 kg) were used in a randomized block design (2007, CRD), blocked by previous treatment and randomly allotted to pastures with four animals per 1.2-ha paddocks and five replications per treatment. Treatments were ADM Alliance Nutrition, Inc. mineral products: 1) Mastergain (R) mineral = Control; 2) Endo-Fighter (R) mineral; 3) Prototype mineral. Animals had free choice access to E+ grass, water and shade.Heifers were weighed on d 0, 1, 28, 56, 83, and 84 (2006) and on d 0, 1, 22, 43, 64, and 85 (2007). In 2006 data collected were initial, d 28, d 56, and final weights, and ADG. In 2007 data collected were initial, d 22, d 43, d 64, and final weights, and ADG for each period. Blood serum was collected at each weigh date for prolactin analysis. Mineral consumption and animal grazing behavior were determined at 14-d intervals. Data were analyzed using the MIXED procedure of SAS. For all variables, contrasts were performed to compare Control to mineral supplements containing Endo-Fighter (R) or Prototype.In 2006 total ADG (kg) and average daily mineral consumption (g) were: 0.61, 170*; 0.56, 122*; 0.50, 146; for Control, Endo-Fighter (R) and Prototype, respectively (*P < .09). In 2007 data were 0.61, 134; 0.57, 147; 0.56, 116; for Control, Endo-Fighter (R), and Prototype, respectively. For both years, serum prolactin was not different (P > 0.05) among treatments. Animal performance and prolactin levels were not significantly affected by the feeding of Endo-Fighter (R) or Prototype in these trials. However, lack of response to Endo-Fighter (R) and Prototype in 2006 may have been attributed to mild weather conditions. In 2007 lack of response may have been a result of extreme heat and drought conditions.

No description available.

Thesis (M.S.)--Ohio State University, 1972. / Includes bibliographical references (leaves 94-96). Available online via OhioLINK's ETD Center

Thesis (M.S.)--University of Kentucky, 2004. / Title from document title page (viewed June 21, 2004). Document formatted into pages; contains vii, 112 p. : ill. Includes abstract and vita. Includes bibliographical references (p. 104-110).

Published also as Thesis (Ph. D.)--Columbia University, 1928. / Bibliography: p. 33.

Thesis (M. Sc.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 84-93).