Systemic antibiotic treatment of cows with metritis early postpartum does not change the progression of uterine disease or the uterine microbiome at 1 month postpartum.

Background: Postpartum uterine disease (metritis) is common in dairy cows. The disease develops within 1 week after calving and is associated with microbial dysbiosis, fever, and fetid uterine discharge. Cows with metritis have a greater likelihood of developing endometritis and infertility later postpartum. Antibiotic treatment is used to relieve symptoms of metritis but the capacity of antibiotic treatment to improve fertility later postpartum is inconsistent across published studies. We hypothesized that an antibiotic has only a short-term effect on the uterine microbiome and does not change the progression of disease from metritis to endometritis. To test this hypothesis, we studied the effects of systemic antibiotic given to cows diagnosed with metritis and healthy cows early postpartum on the development of endometritis and the uterine microbiome at 1 month postpartum. Results: Cows diagnosed with metritis were compared to healthy ones in a 2 × 2 factorial design, where they were either treated with an antibiotic (ceftiofur hydrochloride) at 7 to 10 days postpartum or left untreated. Cows were slaughtered at one month postpartum and the uterus was assessed for endometritis (presence of purulent material in the uterine lumen and inflammation in the endometrium) and uterine samples were collected for bacteriology and metagenomics (16S rRNA gene sequencing). As expected, the uterine microbiome at disease diagnosis had dysbiosis of typical metritis pathogens (e.g., Fusobacterium, Bacteroides, and Porphyromonas) in diseased compared with healthy cows. At one month postpartum, there was a tendency for more endometritis in metritis cows compared with healthy but antibiotic treatment had no effect on endometritis prevalence regardless of the original disease diagnosis. Likewise, when bacteria were cultured or sequenced, there were a greater number of species (culture) or amplicon sequence variants (ASV; sequencing) in the uterine lumen of cows with metritis. However, antibiotic treatment had no effect on the prevalence of cultured species or the composition of the detected ASV. The uterine microbiome at 1 month postpartum was associated with the clinical observation of the uterus (endometritis or healthy). Conclusions: Early postpartum antibiotic treatment only provides temporary resolution of uterine dysbiosis that is not sustained long-term. Failure to resolve the dysbiosis is associated with a greater prevalence of endometritis in cows with metritis, and the occurrence of endometritis significantly impacts fertility later postpartum.

Toxigenic Endophyte-Infected Tall Fescue and Ergot Alkaloids.

"Fescue toxicosis" and reproductive ergotism present identical toxidromes in late-gestational mares and, likely, other equids. Both toxic syndromes are caused by ergopeptine alkaloids (EPAs) of fungal origin, and they are collectively referred to as equine ergopeptine alkaloid toxicosis (EEPAT). EPAs are produced by either a toxigenic endophyte (Epichloë coenophiala) in tall fescue and/or a nonendophytic fungus (Claviceps purpurea), infecting small grains and grasses. EEPAT can cause hypoprolactinemia-induced agalactia/dysgalactia, prolonged gestation, dystocia, and other reproductive abnormalities in mares, as well as failure of passive transfer in their frequently dysmature/overmature/postmature foals. Prevention relies on eliminating exposures and/or reversing hypoprolactinemia.

Life cycle impact assessment of metal production industries in Australia.

Metal production industries are associated with positive economic benefits, however their activities are significantly resource and energy intensive, contributing to emission of pollutants and greenhouse gases to the environment. The balance between the economic inputs and environmental footprint of the metal production industries determines their contribution to sustainability. This work provides environmental impact assessment of the production of aluminium, copper, gold, iron and steel, lead, nickel and zinc, and considers their contribution to the economy. The emissions of selected representative industries in Australia were sourced from public national emission inventories and used as input parameters in the openLCA software. ReCiPe midpoint and endpoint hierarchist impact assessment methods were used to investigate the environmental impacts of the selected industries. The results indicate that lead, followed by aluminium and nickel production had the largest environmental impacts. The work further revealed the specific emissions for better control for each industry taking into consideration their relative environmental and economic impacts. For instance, adoption of renewable energy sources would significantly decrease the greenhouse gas emissions and the associated environmental impacts of the copper, zinc, gold, and iron and steel production industries. Improvement of sustainability of the production of lead would require further control of trace metal emissions, while for aluminium and nickel production, improved control of emissions of particles and the acidic gases SO2 and NOx.

Diagnostic Challenges and Guidelines Pertaining to Suspected Ruminant Intoxications.

This article addresses diagnostic challenges involving toxicology cases that are multifactorial in nature, often involving sublethal exposures to multiple toxicants and/or other etiologies that are not toxic. Gold standard diagnostic approaches were developed under the assumption that cases were undoubtedly intoxications, and they still are applicable to those cases. A more integrated diagnostic approach, focusing on the initial problem list, is consistent with how veterinarians diagnose most cases. Livestock ownership attitudes continue to evolve. Ongoing threats to the financial well-being of animal agriculture ultimately will have an impact on the ability of producers to maintain health and performance of livestock.

Application of national pollutant inventories for monitoring trends on dioxin emissions from stationary industrial sources in Australia, Canada and European Union.

Industrial sources, including iron ore sintering, municipal waste incineration and non-ferrous metal processing have been prominent emitters of dioxins to the environment. With the expanding industrial sectors, many international conventions were established in order to reduce the emission of dioxins in the past two decades. The Stockholm convention, a global monitoring treaty, entered into force in 2004 with the aim to promote development of strategies to reduce or eliminate dioxin emissions. According to the convention, parties are required to develop national inventory databases to report emission levels and develop a national implementation plan (NIP) to reduce further dioxin emissions. In order to understand the trend of dioxin emissions since 1990s this study provides a comparative assessment of dioxin emissions from different industrial sources by deriving emission data from the national inventory databases of Australia, Canada and the 28 European countries (EU-28). According to the data collected, iron and steel production and electricity generation were the highest emitters of dioxins in 2017 for Europe, Canada and Australia, when compared to other stationary industrial sources. The change in the trend of dioxin emissions from the iron and steel industry and the public electricity sector was also assessed. The emission of dioxins during 1990-2017 from both iron and steel production and electricity generation revealed a relative decreasing trend, except for Spain and Italy who showed higher level of emissions from iron and steel production in 2017. Furthermore, comparing emission data for metal production revealed that the blast furnace process was the prominent emitter of dioxins comparing to electric arc furnace process. Further investigation was performed to compare the amount of dioxin emitted from three different fuel types, black coal, brown coal and natural gas, used for electricity generation in Australia. The study showed that dioxin emissions from brown coal were higher than black coal for the last two years, while power production from natural gas emits the lowest amounts of dioxins to the environment.

Immune complex glomerulonephritis of suspected iatrogenic origin in five Japanese Black calves.

Five Japanese Black embryo transfer calves from a single embryo flush, 30 to 45-days-old, including 4 live animals for clinical examination and 1 dead for necropsy, were presented with a history of decreased milk intake and hypoproteinemia. Consistent clinicopathological abnormalities in the 4 calves presented for clinical evaluation included hyperkalemia, hyperphosphatemia, hypoproteinemia, hypoalbuminemia, hyperbilirubinemia, increased creatine phosphokinase activity, and proteinuria. Four calves ultimately were necropsied and all had histologic evidence of immune complex glomerulonephritis. Glomerulonephritis in these calves was hypothesized to have resulted from the interaction of passively acquired antibodies at birth and active immunization at 7 and 28 days of age with a Salmonella Typhimurium core antigen vaccine.

Isolation of Aureimonas altamirensis, a Brucella canis-like bacterium, from an edematous canine testicle.

Microbiological and histological analysis of a sample from a swollen testicle of a 2-year-old Border Collie dog revealed a mixed infection of the fungus Blastomyces dermatitidis and the Gram-negative bacterium Aureimonas altamirensis. When subjected to an automated microbial identification system, the latter isolate was provisionally identified as Psychrobacter phenylpyruvicus, but the organism shared several biochemical features with Brucella canis and exhibited agglutination, albeit weakly, with anti-B. canis antiserum. Unequivocal identification of the organism was only achieved by 16S ribosomal RNA gene sequencing, ultimately establishing the identity as A. altamirensis. Since its first description in 2006, this organism has been isolated infrequently from human clinical samples, but, to the authors' knowledge, has not been reported from a veterinary clinical sample. While of unknown clinical significance with respect to the pathology observed for the polymicrobial infection described herein, it highlights the critical importance to unambiguously identify the microbe for diagnostic, epidemiological, infection control, and public health purposes.

Copper toxicosis in a Boer goat.

A 1-year-old female Boer goat was presented with a 1-day history of pigmenturia, anorexia, and shivering. Anemia was not present initially, but progressive hemolytic anemia developed subsequently and was characterized by the finding of Heinz bodies in both intact RBCs and in ghost cells and the presence of atypical fusiform RBCs. Plasma biochemical analysis revealed increased activities of aspartate aminotransferase and gamma-glutamyltransferase, hyperbilirubinemia, and azotemia. Histopathologic examination of a liver biopsy revealed necrosis of individual hepatocytes and intracytoplasmic rhodamine-positive granules, consistent with copper. Copper concentration in ante-mortem hepatic tissue was increased, and a diagnosis of copper toxicosis was made. Despite supportive therapy, the goat continued to decline and was euthanized. Necropsy findings included hepatic necrosis and hemoglobinuric nephrosis. Freshly collected specimens of liver and kidney had markedly increased copper concentrations. The mineral composition of the water, grass hay, and goat chow was evaluated, and toxins and significant mineral imbalances were not found. The underlying cause of the hepatic accumulation and subsequent release of copper remains unclear in this goat. Recently, Boer goats have been recognized as being prone to copper toxicosis and may be more susceptible than other breeds; similar to sheep, Boer goats may experience a hemolytic crisis secondary to copper toxicosis.

Diminished reproductive performance and selected toxicants in forages and grains.

This article discusses reproductive toxicants as the potential, primary causes of observed reproductive abnormalities and other variables that can affect reproductive performance in ruminants. The causes of diminished reproductive performance in ruminants are often multifactorial. It is critical that producers and their veterinarians understand the potential effects of physiologic and genetic predispositions and nutritional, environmental, infectious, and toxic stressors, as well as interactions involving management. The recognition and prevention of the adverse reproductive effects of these enzootic toxic stressors are essential for optimal ruminant reproductive performance and profitability of a ruminant production system.

The endocrine disruptive effects of ergopeptine alkaloids on pregnant mares.

During equine gestation, ergopeptine alkaloid exposure is not uncommon, and pregnant mares are particularly sensitive to the endocrine disruptive effects of these compounds on lactogenesis and steroidogenesis. Agalactia, prolonged gestation, abortion, dystocia, and placental and fetal abnormalities are all clinical manifestations of changes in the endocrine milieu induced by the ingestion of ergopeptine alkaloid-contaminated feedstuffs by mares during late gestation. An understanding of the endocrine disruptive effects of gestational exposure to ergopeptine alkaloids is necessary for the diagnosis of potential exposures to these compounds and for effective prophylaxis and therapy.

Tremetone and structurally related compounds in white snakeroot ( Ageratina altissima ): a plant associated with trembles and milk sickness.

Ingestion of white snakeroot ( Ageratina altissima ) can cause trembles in livestock and milk sickness in humans. The toxicity has been associated with tremetol, a relatively crude, multicomponent lipophilic extract of the plant. In this study, 11 different compounds were isolated from white snakeroot-derived lipophilic extracts from 18 collections. Six of the isolated compounds have not been previously reported to be found in white snakeroot. High-performance liquid chromatography (HPLC) analysis indicated that there are three different chemotypes of white snakeroot from the plant samples analyzed. Elucidation of these chemotypes may explain the sporadic and unpredictable toxicity of white snakeroot to livestock and humans.

Mutational insertion of a ROSA26-EGFP transgene leads to defects in spermiogenesis and male infertility in mice.

Pronuclear injection has been a successful strategy for generating genetically engineered mouse models to better understand the functionality of genes. A characteristic of pronuclear injection is that random integration of the transgene into the genome can disturb a functional gene and result in a phenotype unrelated to the transgene itself. In this study, we have characterized a mouse model containing an insertional mutation that, in the homozygous state, severely affects spermatogenesis as characterized by lack of sperm motility and acrosomal aplasia. Whereas homozygous female mice had normal fertility, male mice homozygous for the insertional mutation were unable to produce pups by natural mating with either homozygous or wild-type female mice. No fertilized embryos were produced by matings to homozygous male mice, and no sperm were present in the reproductive tract of mated female mice. Spermatozoa isolated from homozygous male mice exhibited head and midpiece defects, but no major defects in the principal piece of these sperm. Histologic examination and immunohistochemical staining of the testes revealed vacuolar degeneration of Sertoli cells and loss of structural seminiferous tubule integrity and organization, indicating that spermatogenesis is severely affected in this mouse model. Although the males are always infertile, the severity of the histologic and sperm morphologic defects appeared to be age-related.

Quantitative method for the measurement of three benzofuran ketones in rayless goldenrod (Isocoma pluriflora) and white snakeroot (Ageratina altissima) by high-performance liquid chromatography (HPLC).

White snakeroot ( Ageratina altissima ) and rayless goldenrod ( Isocoma pluriflora ) can cause "trembles" and "milk sickness" in livestock and humans, respectively. Tremetol, a complex mixture of sterols and derivatives of methyl ketone benzofuran has been extracted from white snakeroot and rayless goldenrod and is reported to be the toxic substance in plant material. In this study, the three major benzofuran ketones, tremetone, dehydrotremetone, and 3-oxyangeloyl-tremetone, were isolated from rayless goldenrod. Using these compounds as standards, a quantitative high-performance liquid chromatography (HPLC) method was developed to measure these compounds in white snakeroot and rayless goldenrod. Concentrations of tremetone, dehydrotremetone, and 3-oxyangeloyl-tremetone were found to vary considerably among the different white snakeroot and rayless goldenrod plant collections. Differences in concentrations of tremetone, dehydrotremetone, and 3-oxyangeloyl-tremetone in white snakeroot and rayless goldenrod plants may explain the historical sporadic and unpredictable toxicity of these plants to livestock and humans.

Copper toxicosis with hemolysis and hemoglobinuric nephrosis in three adult Boer goats.

Acute and, particularly, chronic copper exposures, along with defects in hepatic copper metabolism, altered excretion of copper, and/or nutritional imbalances between copper and other trace elements, can lead to hepatic accumulation of copper and primary copper toxicosis. There is interspecies variation in susceptibility to copper toxicosis, with sheep being the species most likely to develop this condition. Adult dairy goats and Boer crosses are generally considered resistant to chronic copper toxicosis, especially the hemolytic stage of this disease. The current report is rather unusual in that it describes instances of naturally occurring copper toxicosis with hemolysis and hemoglobinuric nephrosis in 3 adult Boer goats. In 2 of these goats, a possible source of excessive dietary copper was investigated but not definitively identified. In the third goat, the etiologic factors associated with the copper toxicosis were not determined. It appears that mature Boer goats are susceptible to the hemolytic stage of chronic copper toxicosis, which was not observed in a recent, large-scale copper intoxication involving lactating dairy goats. Copper analyses on both liver and kidney samples were necessary to confirm the diagnosis of copper toxicosis in all 3 goats. All feedstuffs associated with instances of copper toxicosis should be analyzed for iron, molybdenum, sulphur, and zinc as well as copper to determine what nutritional factors are contributing to the pathogenesis of this disease. Consideration also should be given to the ingestion of hepatotoxic plants and other toxic exposures, which could predispose an animal to secondary chronic copper toxicosis.

Thermal processing of paper sludge and characterisation of its pyrolysis products.

Paper sludge is a waste product from the paper and pulp manufacturing industry that is generally disposed of in landfills. Pyrolysis of paper sludge can potentially provide an option for managing this waste by thermal conversion to higher calorific value fuels, bio-gas, bio-oils and charcoal. This work investigates the properties of paper sludge during pyrolysis and energy required to perform thermal conversion. The products of paper sludge pyrolysis were also investigated to determine their properties and potential energy value. The dominant volatile species of paper sludge pyrolysis at 10 degrees C/min were found to be CO and CO(2), contributing to almost 25% of the paper sludge dry weight loss at 500 degrees C. The hydrocarbons (CH(4), C(2)H(4), C(2)H(6)) and hydrogen contributed to only 1% of the total weight loss. The bio-oils collected at 500 degrees C were primarily comprised of organic acids with the major contribution being linoleic acid, 2,4-decadienal acid and oleic acid. The high acidic content indicates that in order to convert the paper sludge bio-oil to bio-diesel or petrochemicals, further upgrading would be necessary. The charcoal produced at 500 degrees C had a calorific value of 13.3MJ/kg.

Relationships between demographic variables and lead toxicosis in cattle evaluated at North American veterinary teaching hospitals.

OBJECTIVE: To determine associations between age, sex, breed, and month and year of admission and the diagnosis of lead toxicosis in cattle. DESIGN: Retrospective case-control study. Sample Population-Records of all cattle evaluated at North American veterinary teaching hospitals during the years 1963 to 2002, which were available through the Veterinary Medical Database. PROCEDURES: Logistic regression was used to evaluate the associations between postulated risk factors and the occurrence of lead toxicosis in cattle and predict the occurrence of the diagnosis of lead toxicosis in cattle. RESULTS: 413 cases of lead intoxication and 202,363 control cattle were identified and met the inclusion criteria. Cattle < 4 years of age were at increased risk for the diagnosis of lead intoxication relative to cattle > or = 4 years of age. Cattle > or = 2 months and < 6 months of age had the greatest risk for lead intoxication (odds ratio, 12.3). Angus cattle were at greater risk for toxicosis (odds ratio, 1.95), compared with other breeds. The risk of lead toxicosis was greater before 1985 (odds ratio, 1.94) than the risk thereafter. The risk of lead toxicosis diagnosis was greatest in the months of May, June, July, and August. CONCLUSIONS AND CLINICAL RELEVANCE: Lead toxicosis in cattle was associated with age < 4 years and the Angus breed. A seasonal pattern existed with peak occurrence in the late spring and summer. The occurrence of lead toxicosis has declined over time.

Thermal conversion of elephant grass (Pennisetum purpureum Schum) to bio-gas, bio-oil and charcoal.

Elephant grass is an abundant, fast growing plant with significant potential as a renewable energy source and for conversion to higher calorific value fuels. This work investigates thermal conversion of elephant grass to bio-gas, bio-oil and charcoal under two heating rates of 10 and 50 degrees C/min. The energy required to pyrolyse elephant grass was evaluated using computer aided thermal analysis technique, while composition of the resultant bio-gas and bio-oil products were monitored with gas chromatographic and mass spectroscopic techniques. At 500 degrees C, the bio-gas compounds consisted primarily of CO2 and CO with small amounts of methane and higher hydrocarbon compounds. The heat of combustion of the bio-gas compounds was estimated to be 3.7-7.4 times higher than the heat required to pyrolyse elephant grass under both heating rates, which confirms that the pyrolysis process can be self-maintained. Faster heating rate was found to increase the amount of liquid products by 10%, while charcoal yields remained almost the same at 30%. The bio-oil mainly consisted of organic acids, phthalate esters, benzene compounds and amides. The amount of organic acids and benzene compounds were significantly reduced at 50 degrees C/min, while the yields of phthalate esters and naphthalene compounds increased. The difference in bio-oil composition with increased heating rate is believed to be associated with the reduction of the secondary reactions of pyrolysis, which are more pronounced under lower heating rate.

Effect of ergot alkaloids associated with fescue toxicosis on hepatic cytochrome P450 and antioxidant proteins.

Intake of ergot alkaloids found in endophyte-infected tall fescue grass is associated with decreased feed intake and reduction in body weight gain. The liver is one of the target organs of fescue toxicosis with upregulation of genes involved in xenobiotic metabolism and downregulation of genes associated with antioxidant pathways. It was hypothesized that short-term exposure of rats to ergot alkaloids would change hepatic cytochrome P450 (CYP) and antioxidant expression, as well as reduce antioxidant enzyme activity and hepatocellular proliferation rates. Hepatic gene expression of various CYPs, selected nuclear receptors associated with the CYP induction, and antioxidant enzymes were measured using real-time PCR. Hepatic expression of CYP, antioxidant and proliferating cell nuclear antigen (PCNA) proteins were measured using Western blots. The CYP3A1 protein expression was evaluated using primary rat hepatocellular cultures treated with ergovaline, one of the major ergot alkaloids produced by fescue endophyte, in order to assess the direct role of ergot alkaloids in CYP induction. The enzyme activities of selected antioxidants were assayed spectrophotometrically. While hepatic CYP and nuclear receptor expression were increased in ergot alkaloid-exposed rats, the expression and activity of antioxidant enzymes were reduced. This could potentially lead to increased oxidative stress, which might be responsible for the decrease in hepatocellular proliferation after ergot alkaloid exposure. This study demonstrated that even short-term exposure to ergot alkaloids can potentially induce hepatic oxidative stress which can contribute to the pathogenesis of fescue toxicosis.

In vitro efficacy of lufenuron against filamentous fungi and blood concentrations after PO administration in horses.

Lufenuron is a benzoylphenyl urea-derived insecticide that has been recently introduced as a novel treatment for fungal infections in horses. The purposes of this study were to determine (1) the in vitro efficacy of lufenuron against Aspergillus and Fusarium spp. and (2) the ability of lufenuron to reach efficacious blood concentrations after PO administration in horses. Fungal colonies isolated from diseased equine corneas were tested against lufenuron solutions up to 700 microg/mL. Twenty-one adult horses received 1 of 3 PO lufenuron treatment regimens: 5 mg/kg body weight (BW) q24h for 3 days, 20 mg/kg BW q24h for 3 days, or 60 mg/ kg BW q24h for 1 day. Blood samples were collected up to 96 hours after drug administration and analyzed by high-performance liquid chromatography. Statistical analyses of lufenuron blood concentrations were performed by analysis of variance and Fischer's Least Significant Difference test, with statistical significance set at P < .05. Lufenuron showed no effect on the in vitro growth of Aspergillus or Fusarium spp. Lufenuron was detected in the blood of all but 1 horse and showed no adverse effects. The maximum blood lufenuron concentration (83.5 +/- 58.7 microg/L) was lower than the concentrations proven to be ineffective in vitro in this study. Further therapeutic use of lufenuron as an antifungal agent in horses should be based on proven efficacy against specific strains of clinically relevant fungi with pharmacokinetic data demonstrating sufficient lufenuron concentrations in target tissues.