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.

Studies were conducted to investigate the prevalence and potential for transfer of class 1 integrons and antimicrobial resistance in bacteria of broiler chickens and swine from the US and Thailand. Antibiograms were characterized and integron sequences were detected using standard methods. To determine if transfer of integrons occurred between bacterial species the location of the integrons (plasmid versus chromosome) was determined, and when integron-positive E. coli and Salmonella isolates possessed identical amplicon patterns, PCR products were sequenced to determine homology. Class 1 integrons were detected in 1,732 of 3,824 isolates from broiler chickens and 1,782 of 4,253 isolates from swine. Simultaneous presence of three conserved class 1 integron genes was found in 1,044 and 215 of isolates from chickens and swine, respectively. A high proportion of bacterial isolates from chickens demonstrated resistance to tetracycline, sulfamethoxazole, cephalothin, and ampicillin. A high proportion of isolates from swine demonstrated resistance to tetracycline, sulfamethoxazole, streptomycin, and ampicillin. Nine integron amplicons, with sizes ranging from 0.5 to 2.5 kb, were found, and we discovered a single swine farm on which similar integrons were observed in both E. coli and Salmonella. Sequence analysis revealed that a 1.0 kb amplicon found in both bacterial species contained an aadA1 gene cassette encoding aminoglycosides 3’-adenyltransferase, confering resistance to streptomycin and spectinomycin. A 2.0 kb amplicon was also found in both types of bacteria containing the aadA5 gene encoding aminoglycosides 3’-adenyltransferase, an additional reading frame with unknown function, orfD, as well as a dfrA17 gene encoding dihydrofolate reductase, conferring resistance to trimethoprim. Our results indicate that class 1 integrons are common in commensal and foodborne bacteria in broiler chickens and swine, and that some, but not all antibiotic resistances are associated with the presence of class 1 integrons. Identical integrons found in Salmonella and E. coli from a single farm likely indicate transfer between these two organisms occurs via exchange of plasmids. This work provides additional knowledge regarding the complex nature of antibiotic resistance gene acquisition, reservoirs, and transfer that should aid in development of courses of action and strategies for control of these potential foodborne and zoonotic hazards.

The overall aim of the studies described herein was to evaluate bovine spermatogonial cell dynamics under various conditions. Results from these experiments will provide the basis for potential production of offspring following spermatogonial stem cell transfer. Experiment 1 evaluated gonadotropin administration effects at initiation of inhibin passive immunization in Jersey bull calves on testicular morphology and development. Primary treatments consisted of control (KLH) or immunization (INH) plus a combination of saline, FSH, or GnRH. Administration of FSH at the time of initial immunization against inhibin significantly increased number of germ cells (92.2 ± 9 x 106 cells) compared to INH-Saline bulls (54.9 ± 10 x 106 cells) with INH-GnRH bulls being intermediate (64.5 ± 9 x 106 cells; P < 0.05). These results suggested that gonadotropin administration at time of inhibin immunization increases number of germ cells in the testis. Experiment 2 evaluated transiently induced ischemia in testes of Jersey calves on morphology and development. Treatments consisted of control or banding for 2 h, 4 h, and 8 h periods. Transiently induced ischemia significantly decreased number of germ cells in 8 h (12.6 ± 5 x 106 cells) compared to 0 (38.1 ± 6 x 106 cells), 2 (31.9 ± 6 x 106 cells), and 4 h (33.4 ± 5 x 106 cells; P < 0.05). These results suggested that transiently-induced ischemia significantly decreases number of germ, Sertoli and Leydig cells in the testis. Experiment 3 evaluated spermatogonial stem cells (SSC) proliferation, isolated from prepubertal and adult bulls, during short term in vitro culture. Spermatogonia were cultured in the presence or absence of a feeder monolayer (FL or NF), FBS type (FBS-S or FBS-SF), and media type (ELSC or RSC) treatment combinations. Viable type A spermatogonia survived under in vitro conditions and were able to proliferate and form different types of colonies. Furthermore, co-culture spermatogonial cells with a feeder monolayer plus FBS-S enhanced colony number (may be due to increasing cell viability). At 15 days of culture, colonies from both types of bulls were positive to AP. Therefore, these finding provide the basis for potential production of offspring through in vitro genetic manipulation such as intracytoplasmic sperm injection (ICSI), round spermatid injection (ROSI), or following SSC transfer.

Heat-induced reductions in developmental competence after direct exposure of oocytes to 41ºC have been coincident with reduced protein synthesis. Since heat stress perturbs RNA integrity and polyadenylation in somatic cells, it was hypothesized that heat stress during meiotic maturation may alter RNA within oocytes and/or their surrounding cumulus to account for some of the reductions in development. Initial efforts utilized microcapillary electrophoresis to examine oocyte and cumulus RNA without heat stress as a first step toward transcriptome profile analysis. Size distribution of RNA, rRNA ratio, and other related endpoints differed for oocyte RNA compared to cumulus, and were conserved across other mammalian species. Size distribution of polyadenylated RNA after amplification was similar for oocytes and cumulus. Effects of heat stress on total and polyadenylated RNA, RNA size distribution, and individual transcripts important for meiotic maturation and response to heat stress were examined in oocytes and cumulus during maturation, and resultant embryos after fertilization. There was no impact of heat stress during the first 12 h of maturation to alter size distribution of RNA, rRNA ratio, and other endpoints in oocytes or cumulus. Heat stress perturbed the abundance of polyadenylated RNA in oocytes in one study. Abundance of eight examined transcripts was not altered after exposure to elevated temperature, suggesting that the impact of heat stress on oocyte RNA, if any, was subtle. Consequences of elevated temperature exposure during maturation on transcriptomes of oocytes and their surrounding cumulus vestment were investigated using microarray technology. Thousands of transcripts changed in oocytes and surrounding cumulus over meiotic maturation, some in a stage-specific and amplification-dependent manner. Culture at elevated temperature for the first 12 h of meiotic maturation impacted a small proportion of transcripts in matured oocytes and cumulus at 24 h. Alterations suggested perturbations in oocyte mitochondrial function, and intracellular signaling and extracellular matrix production in cumulus. Heat-induced alterations in oocyte mitochondria and cumulus expansion are supported by existing literature. The findings discussed here are informative of heat-induced molecular alterations in oocytes and cumulus and may prove useful for development of strategies to mitigate negative impacts of heat stress on fertility.

An experiment was conducted to determine effects of anti-Salmonella egg yolk antibodies (ASEYA) on shedding and antibiotic resistance of Salmonella enterica Typhimurium and E. coli, growth performance and immunological parameters. Weaned pigs in two replicate trials (n = 132) were randomly assigned to six dietary treatments, including a control diet without additives, apramycin followed by carbadox, oxytetracycline (OXY), egg yolk powder containing ASEYA, egg yolk powder lacking ASEYA, or spray dried plasma protein (SDPP). Treatments were given to pigs on day 3 of the trial and all pigs were intranasally and orally challenged with Salmonella Typhimurium containing a nalidixic acid resistance marker on day 7. Fecal samples were collected on day 0, 7, 8, 12, 14, 21, 58, 88, and 118 for detection of Salmonella and E. coli to determine shedding and antibiotic resistance. Blood samples were collected and rectal temperatures (RT) were measured on day 0, 7, 8, 12, 14, 21, and 28. Blood was analyzed for white blood cell (WBC) counts and serum was analyzed for Salmonella antibody and interleukin-1β (IL-1β). The percentage of pigs shedding Salmonella was lower (P<0.05) for antibiotic treatments compared to other diets; however, resistance was greater (P<0.05) in E. coli from pigs fed antibiotics. Weight gains did not differ between treatments. Pigs fed OXY had lower RT compared to pigs fed SDPP and ASEYA (P<0.05); however, pigs in all groups had higher RT 24 h after challenge (P<0.05) and had decreasing RT by day 12. Concentrations of anti-Salmonellaa antibodies and WBC counts did not differ between treatment groups. Salmonella antibody concentrations increased in all groups beginning on day 14 and continued to increase through day 28 (P<0.05). IL-1β was generally below detection limits. These studies indicate that in-feed ASEYA may not be effective in controlling shedding of Salmonella or improving the performance or health status of pigs challenged with Salmonella likely because ASEYA cannot reach invasive Salmonella that move through routes outside of the GI tract and/or because ASEYA lose activity as a result of animal digestive processes.

Thinning, herbicide release, and prescribed fire have been used to increase forage availability in pine forests for white-tailed deer, rivaling that available in warm-season food plots. Related data are lacking for hardwood forests. I measured forage availability following 7 silvicultural treatments, including controls (C), forest regeneration methods, and Timber Stand Improvement practices in 4 upland mixed hardwood stands, July–September 2007 and 2008. I also measured forage availability in 4 paired warm-season food plots, including soybeans, lablab, and iron-andclay cowpeas, July–September 2007, and three varieties of soybeans, July–October 2008. I compared nutritional carrying capacity (NCC) of selected species and species from the literature at 3 crude protein nutritional constraints (diet) between forest treatments and food plot plantings. For both years of the study, retention cut with fire (RF) and shelterwood with fire (SF) tended to have the greatest NCC, regardless of species list or diet constraint. Understory triclopyr applications killed woody species following retention cut with herbicide, but relative biomass contribution of woody and herbaceous species returned to original levels two years post treatment. Herbicide applications did not increase NCC. Production of forage plantings exceeded forest treatments in 2007, but RF production was similar to 4.6 and 5.6 soybeans in 2008. Lablab, cowpeas, and later-maturing varieties of soybeans maintained production longer than the early-maturing soybean. Lablab and late-maturing soybeans were the most cost effective plantings. Forage plantings were inexpensive compared to forest treatments (excluding shelterwood) in the short-term, but RF was comparable when using species from the literature after 2 years, and becomes more cost effective after 4 years. I encourage landowners interested in increasing available nutrition for white-tailed deer to manage upland hardwood forests using canopy reduction and prescribed fire. When coupled with population reduction, food plots can be an important management practice where deer exceed NCC.

No description available.

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.