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Lyme disease (LD), caused by the bacterium Borrelia burgdorferi and transmitted by blacklegged ticks (Ixodes scapularis), is the most commonly reported vector-borne disease in the United States. Lyme disease is endemic in northeastern states, whereas southern states report far fewer cases. This research evaluated the potential LD health risk to humans associated with blacklegged ticks in Tennessee. I surveyed 1,018 hunter-harvested deer from 71 counties in fall 2007 and fall 2008. Of these, 160 (15.7%) from 35 counties were infested with I. scapularis — 30 of the counties were new distributional records for this species. I also evaluated the seasonal phenology of I. scapularis at Henry Horton State Park (HHSP) in middle Tennessee by drag sampling and small mammal trapping from November 2007 to May 2009. Larval I. scapularis numbers per 1000m2 dragged peaked at 4.1 ± 2.9SE in July, nymphs peaked at 5.0 ± 3.5SE in March, and adults at 12.0 ± 1.2SE in November. Overall, 191 mice (Peromyscus spp.) were captured on 355 occasions – I. scapularis ticks were present on 68 (19%) of these occasions. Larval I. scapularis infestation of mice peaked in June (8 of 12 mice; 67%); nymphal infestation peaked in May (3 of 16; 19%). DNA was extracted from the I. scapularis collected from deer (883 samples), and at HHSP (283 samples) and tested for B. burgdorferi and other Borrelia using PCR targeting the 16s-23s intergenic spacer region of these bacteria. No B. burgdorferi was detected, although four samples tested positive for B. miyamotoi. I conclude that I. scapularis is far more widespread in Tennessee than previously reported. At HHSP, the abundance of this tick reaches levels that sustain endemic cycles of B. burgdorferi in the Northeast. Moreover, their seasonal phenology in Tennessee – whereby nymphal questing precedes larval questing – should favor B. burgdorferi transmission. Nevertheless, B. burgdorferi was not detected in these Tennessee tick populations, so the LD risk to humans posed by I. scapularis in Tennessee appears to be very low at the present time. Future ecological studies are needed to explain the lack of B. burgdorferi infection in these Tennessee ticks.

Acute control of prostaglandin production is essential for normal estrous cyclicity and maintenance of early pregnancy. The rate limiting step for prostaglandin production is the activation of Phospholipase A2. There are many phospholipase A2s, but few have been investigated in reproductive studies. The objective of this study was to examine PLA2 Groups IV and VI protein and mRNA expression in the uterine endometrium during the estrous cycle and early pregnancy in ewes. Ewes were monitored for estrous and uterine tissues were collected surgically on days 5 (n=3), 10(n=3) and 15(n=3) of the estrous cycle. Endometrium from pregnant animals were harvested on days 14(n=3), 15(n=1), 16(n=2), 17(n=1) or 20(n=2). Endometrial scrapings were collected in attempts to harvest luminal epithelial cells primarily and tissue samples were collected to harvest samples containing all cellular endometrial components. Samples were analyzed by western blot analysis and qRT-PCR to detect protein and mRNA expression of both PLA2s Group IV and VI. Western blot results revealed that protein expression of Group IVA was greatest on day ten of the estrous cycle but was not significantly different form days 5 and 15, possibly due to animal variation. Group IVA was significantly elevated on day 14 of pregnancy (P<0.05) and remained elevated until day 16 when it diminished and a 50kD band appeared. Group VIA analysis showed a cross-reactive 50kD band that showed no significant change. qRT-PCR analysis for Group IVA of scraping samples revealed similar findings showing not only an increase of Group IVA mRNA at pregnancy but also during day 10 of the estrous cycle (P<0.0001) but little difference was seen in tissue samples (P<0.0001). Group VIA was shown to have no mRNA difference in both tissue and scraping samples. These results suggest that PLA2 expression is not the sole regulator of prostaglandin production, but it does play an integral role that is tissue and cell type specific in both the estrous cycle and early pregnancy.

The objectives of this study were to determine: (1) the effects of weather upon toxicity of grains treated with zinc phosphide, (2) the acceptance by prairie voles of weathered bait, (3) the LD50 of zinc phosphide on selected rodent species, and (4) the potential hazard of secondary poisoning to predators fed prey poisoned with zinc phosphide. The rate of loss of zinc phosphide from the bait vehicle was significantly greater during the first week of exposure than in the succeeding three weeks; approximately 34 and 31 percent of the toxic material was lost in April and November, respectively, during the first week the bait was placed in the field. White mice (Mus musculus) were fed weathered bait to evaluate the biological significance of weathering on the rodenticide. The number of mice dying was inversely correlated with the time the bait was exposed to weathering. Bait exposed four weeks was believed to be ineffective. Acceptance of the bait by white mice apparently was not influenced by the length of its exposure in the field, Mice accepted bait which had been weathered one and four weeks as readily as fresh bait. The LD50 of zinc phosphide for white mice was determined to be 25.77 +/- 12.16 mg/kg. The LD50 of zinc phosphide for prairie voles was 16.23 +/- 0 mg/kg. The potential hazards of secondary poisoning from rodents killed with zinc phosphide were investigated for three species of predators, red fox (Vulpes fulva), gray fox (Urocyon cinereoargentus), and great horned owls (Bubo virginianus). No predators died from consuming poisoned voles, though some behavioral irregularities developed during the feeding trials.

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.

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.

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.

Previous studies on macrolide resistance in Campylobacter were primarily focused on the isolates from various origins using in vitro systems. In this study, both in vitro and in vivo experiments were conducted to examine the development, stability, and genetic basis of macrolide resistance in C. jejuni. All in vitro and in vivo selected EryR mutants were derived from the same parent strain C. jejuni NCTC 11168. To determine if long-term exposure of low-level EryR C. jejuni to low-dose tylosin selects for high-level EryR mutants (MIC > 512 μg/ml), two low-level EryR mutants (MIC = 32 or 64 μg/ml) were used to inoculate chickens at 15 days of age in two independent experiments. Total and EryR C. jejuni populations in swabs collected at different time points were determined by differential plating and MIC test. The in vitro stability was tested by repeated subculturing of EryR mutants in Ery-free broth medium. The in vivo stability was tested by inoculating 3-day-old chickens (12-13 birds/group) receiving nonmedicated feed with EryR mutants and collecting cloacal swabs from each chickens at 12, 22, 38, and 47 days of age. Total and EryR C. jejuni populations in culture (after 10, 20 and 33 passages) or swab were determined by differential plating and MIC test. Genomic DNA from each of 63 selected EryR mutants was used for PCR amplification and sequence analysis of 23S rRNA gene and ribosomal proteins L4 and L22. Mutation in CmeABC multidrug efflux pump was transferred to EryR strains to determine the role of CmeABC efflux pump in Ery resistance. Chicken studies showed that the length of exposure time to subtherapeutic level of tylosin is not a sole factor contributing to the emergence of highly EryR Campylobacter. Prolonged exposure of low-level EryR C. jejuni (MIC = 32 or 64 μg/ml) to tylosin did not select for highly EryR mutants. The low- level Ery resistance (MIC = 32μg/ml) was stable after 10 passages in vitro but majority of C. jejuni were sensitive to Ery after 20 passages. The instability of low-level Ery resistance was also observed in chickens as early as 9 days postinoculation and EryR mutants were rarely isolated 35 days postinoculation. However, high-level Ery resistance (MIC > 512μg/ml) displayed remarkably stability in vitro and in vivo. All high-level EryR mutants selected in vivo displayed the A2074G mutation in 23S rRNA gene, distinct from the specific mutation (A2074C) observed in all highly EryR mutants selected in vitro. No mutations were observed in ribosomal proteins L4 for all in vitro selected EryR mutants but specific mutations in L4 (G74D or G57D) were widely found in low level EryR mutants selected in vivo (Ery MIC = 8-64 μg/ml). Insertion of three amino acids TSH at position 98 in L22 was only observed in mutants selected in vitro with Ery MIC ranging from 32-512 μg/ml. The CmeABC efflux pump worked synergistically with other mechanisms to confer Ery resistance in C. jejuni. Together, these findings indicated that C. jejuni utilize complex and different mechanisms to develop Ery resistance in vitro and in vivo.

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.

Introduction: The Tennessee Valley Authority is vitally interested in the effect of phosphorous on crop yields and the nutritional value of these crops on livestock. They manufacture different phosphatic fertilizers and test them on farms and in laboratories. Financial assistance is given by the Tennessee Valley Authority to the Tennessee Experiment Station in this study of the feeding value of clover hays of varying phosphorous contents for growing beef calves. This experiment was originated to (1) study growth of calves fed rations differing only in the phosphorous content of the red clover hay; and (2) to study the availability to growing beef calves of the phosphorous in the red clover hays having a different phosphorous content.