Bacterial culture and susceptibility test results for clinical mastitis samples from Australia's subtropical dairy region.

This study aimed to identify the pathogens isolated from the milk of cows with clinical mastitis in the subtropical region of Australia and to determine the antimicrobial susceptibility of these bacteria. Thirty dairy herds in the subtropical dairy region were asked to submit milk samples for the first 5 cases of clinical mastitis each month for 12 mo. Samples underwent aerobic culture, and isolates were identified via MALDI-TOF mass spectrometry. Antimicrobial susceptibility was determined for Escherichia coli, Enterococcus spp., Streptococcus agalactiae, Streptococcus uberis, Streptococcus dysgalactiae, Staphylococcus aureus, and non-aureus staphylococci and mammaliicocci (NASM). Between March 2021 and July 2022, 1,230 milk samples were collected. A positive culture result was recorded for 812 (66%) of the milk samples; from these samples, 909 isolates were obtained, including 49 isolates where no identification was possible. The remaining samples were classified as having no growth (16.8%) or as being contaminated (17.2%). The most common isolates with a MALDI-TOF diagnosis (n = 909) were Strep. uberis (23.6%), followed by the NASM group (15.0%). Farms enrolled in the study were in 3 distinct locations within the subtropical dairy region: North Queensland, Southeast Queensland, and Northern New South Wales. Some variation in isolate prevalence occurred between these 3 locations. We found lower odds of a sample being positive for E. coli in North Queensland (odds ratio [OR]: 0.25; 95% confidence interval [CI]: 0.07-0.87) and higher odds in Southeast Queensland (OR: 4.01; 95% CI: 1.96-8.20) compared with the reference, Northern New South Wales. We further found higher odds of Strep. dysgalactiae in North Queensland (OR: 5.69; 95% CI: 1.85-17.54) and Southeast Queensland compared with Northern New South Wales (OR: 3.99; 95% CI: 1.73-9.22). Although some seasonal patterns were observed, season was not significant for any of the analyzed isolates. Farm-level differences in pathogen profiles were obvious. Overall, clinical mastitis pathogens had low levels of resistance to the antimicrobials tested. This research demonstrates that Strep. uberis and the NASM bacterial group are the most common pathogens causing clinical mastitis in the subtropical dairy region. It highlights the importance of understanding pathogenic causes of mastitis at the farm and regional level for targeted control and therapy.

Sequence level genome-wide associations for bull production and fertility traits in tropically adapted bulls.

BACKGROUND: The genetics of male fertility is complex and not fully understood. Male subfertility can adversely affect the economics of livestock production. For example, inadvertently mating bulls with poor fertility can result in reduced annual liveweight production and suboptimal husbandry management. Fertility traits, such as scrotal circumference and semen quality are commonly used to select bulls before mating and can be targeted in genomic studies. In this study, we conducted genome-wide association analyses using sequence-level data targeting seven bull production and fertility traits measured in a multi-breed population of 6,422 tropically adapted bulls. The beef bull production and fertility traits included body weight (Weight), body condition score (CS), scrotal circumference (SC), sheath score (Sheath), percentage of normal spermatozoa (PNS), percentage of spermatozoa with mid-piece abnormalities (MP) and percentage of spermatozoa with proximal droplets (PD). RESULTS: After quality control, 13,398,171 polymorphisms were tested for their associations with each trait in a mixed-model approach, fitting a multi-breed genomic relationship matrix. A Bonferroni genome-wide significance threshold of 5 × 10- 8 was imposed. This effort led to identifying genetic variants and candidate genes underpinning bull fertility and production traits. Genetic variants in Bos taurus autosome (BTA) 5 were associated with SC, Sheath, PNS, PD and MP. Whereas chromosome X was significant for SC, PNS, and PD. The traits we studied are highly polygenic and had significant results across the genome (BTA 1, 2, 4, 6, 7, 8, 11, 12, 14, 16, 18, 19, 23, 28, and 29). We also highlighted potential high-impact variants and candidate genes associated with Scrotal Circumference (SC) and Sheath Score (Sheath), which warrants further investigation in future studies. CONCLUSION: The work presented here is a step closer to identifying molecular mechanisms that underpin bull fertility and production. Our work also emphasises the importance of including the X chromosome in genomic analyses. Future research aims to investigate potential causative variants and genes in downstream analyses.

Concurrently mapping quantitative trait loci associations from multiple subspecies within hybrid populations.

Many of the world's agriculturally important plant and animal populations consist of hybrids of subspecies. Cattle in tropical and sub-tropical regions for example, originate from two subspecies, Bos taurus indicus (Bos indicus) and Bos taurus taurus (Bos taurus). Methods to derive the underlying genetic architecture for these two subspecies are essential to develop accurate genomic predictions in these hybrid populations. We propose a novel method to achieve this. First, we use haplotypes to assign SNP alleles to ancestral subspecies of origin in a multi-breed and multi-subspecies population. Then we use a BayesR framework to allow SNP alleles originating from the different subspecies differing effects. Applying this method in a composite population of B. indicus and B. taurus hybrids, our results show that there are underlying genomic differences between the two subspecies, and these effects are not identified in multi-breed genomic evaluations that do not account for subspecies of origin effects. The method slightly improved the accuracy of genomic prediction. More significantly, by allocating SNP alleles to ancestral subspecies of origin, we were able to identify four SNP with high posterior probabilities of inclusion that have not been previously associated with cattle fertility and were close to genes associated with fertility in other species. These results show that haplotypes can be used to trace subspecies of origin through the genome of this hybrid population and, in conjunction with our novel Bayesian analysis, subspecies SNP allele allocation can be used to increase the accuracy of QTL association mapping in genetically diverse populations.

The Unrecognized Role of VA Call Center and Primary Care Clerical Staff in Assisting Patients with Obtaining Needed Care.

BACKGROUND: VA clerks, or medical support assistants (MSAs), are a critical part of patients' primary care (PC) experiences and are often the first points of contact between Veterans and the healthcare system. Despite the important role they might play in assisting Veterans with accessing care, research is lacking on the specific tasks they perform and what training and preparation they receive to perform their roles. OBJECTIVE: Our primary aim in this study was to document MSA perceptions of their roles, the tasks they undertake helping Veterans with accessing healthcare, and additional training they may need to optimally perform their role. DESIGN: Thematic analysis of semi-structured qualitative interviews with VA call center and PC MSAs (n=29) collected as part of in-person site visits from August to October 2019. PARTICIPANTS: MSAs at administrative call centers and primary care clinics in one large VA regional network representing 8 healthcare systems serving nearly 1.5 million Veterans. KEY RESULTS: We identified three key findings from the interviews: (1) MSAs perform tasks in addition to scheduling that help Veterans obtain needed care; (2) MSAs may not be fully prepared for their roles as first points of contact; and (3) low status and lack of recognition of the important and complex tasks performed by MSAs contribute to high turnover. CONCLUSIONS: As healthcare systems continue expanding virtual access, the roles of administrative call center and PC MSAs as first points of contact will be increasingly important for shaping patient experiences. Our research suggests that MSAs may need better training and preparation for the roles they perform assisting Veterans with accessing care, coupled with an intentional approach by healthcare systems to address MSAs' concerns about recognition/compensation. Future research should explore the potential for enhanced MSA customer service training to improve the Veteran patient experience.

A novel transdermal ketoprofen formulation for analgesia in cattle.

Ketoprofen is registered in many countries for injectable administration in cattle. Because it is soluble in a wide range of excipients, development of a novel transdermal (TD) ketoprofen formulation was pursued to provide a convenient and pain-free route of administration in cattle. One hundred and six excipient combinations were screened using in vitro techniques (Franz diffusion cells), with a 20%(w/v) ketoprofen formulation dissolved in a combination of 45%:45%(v/v) ethanol and isopropyl myristate (IPM) and 10%(v/v) eucalyptus oil achieving maximal penetration of ketoprofen through bovine skin. A bioavailability study was then conducted using a randomized cross-over design (n = 12), including IV, IM (both 3 mg/kg) and TD (10 mg/kg) ketoprofen formulations administered with a one-week washout period between administrations. The IV and IM formulation pharmacokinetic results were as expected. The CMAX , Tmax and AUC0-Last were significantly higher (arithmetic mean ± SD) after TD administration (20.0 ± 6.5 µg/ml, 115 ± 17 min and 3940 ± 1324 µg*min/ml, respectively), compared to IM (11.0 ± 4.0 µg/ml, 74 ± 43 min and 2376 ± 738 µg*min/ml, respectively), although there were no significant differences for T½ß . However, dose corrected values CMAX and AUCinf were significantly higher for IM compared to TD. The arithmetic mean bioavailability (F) of the transdermal formulation was 50%. The plasma concentration of the TD formulation at a dose of 10 mg/kg was similar to the IM formulation at 3 mg/kg by 30 min post-dosing with an arithmetic mean ± SD of 7.97 ± 4.38 vs. 8.02 ± 3.55 µg/ml, respectively. The TD formulation was generally well tolerated by cattle, although some local irritation along the site of application was noted after 12 h of exposure during the bioavailability study. Results indicate that this novel TD formulation provides a substantial improvement in administration convenience, may improve animal welfare and end-user safety through needle-free administration, and achieves similar plasma pharmacokinetics to the IM product when administered at 10 mg/kg.

Pregnancy rate per cycle is heritable and reduces with cycle in naturally mated tropically adapted beef cows.

Pregnancy in cattle is the outcome of the complex process of initiation of cycling, fertilization, maternal recognition of pregnancy and foeto-placental development. Though much is known about initiation of cycling and associated risk factors, there are virtually no data on pregnancy rate per cycle for naturally mated cattle, especially for extensively managed, tropically adapted genotypes, which this study aimed to determine. Tropical composite (Bos indicus and African Sanga crosses with Bos taurus) and Brahman cattle (n = 2,181) of known pedigree in four-year groups at four sites were mated annually for 84 days. Body condition, ovarian function, pregnancies, calving and lactation were monitored through six full reproductive cycles using 4-8 weekly ultrasound of the reproductive tract outside the calving period and daily monitoring during calving. From this, dates of commencement of cycling and conception in each year were estimated for each animal, enabling calculation of established pregnancy for consecutive 21-day periods while cycling and of pregnancies within four months of calving while lactating (P4M). Pregnancy per 21-day period (cycle) during mating for cycling animals averaged 63%, 71%, 41% and 28% in four consecutive cycles. Pregnant per cycle was 2%-11% higher in tropical composites than in Brahmans. The only other consistently significant risk to becoming pregnant was if cycling commenced later than three weeks before mating commenced. P4M averaged 62% and was lower for cows in sub-optimal body condition and in first-parity and later-calving cows. Pregnant per cycle was moderately heritable (~20%), while heritability was moderate to high (33%) for P4M. Selection for pregnant per cycle could be achieved indirectly by selection for P4M, a trait that is readily measured.

Testing of NKA expression by mobile real time PCR is an efficient indicator of smoltification status of farmed Atlantic salmon.

Assessment of seawater readiness of freshwater salmon smolts is a crucial husbandry step with economic implications in salmon aquaculture but current methods rely on delayed centralised enzymic activity measurement. The efficiency of a qRT-PCR assay for sodium potassium ATPase (NKA) α1a mRNA was tested in a 3-year study on 19 hatcheries across Scotland incorporating environmental factors such as temperature and metal contamination. The NKA qRT-PCR assay was transferred to a mobile laboratory and on-site testing was carried out at 3 hatchery sites. For the first two years standard enzymatic and gene expression assays had similar success rates in detecting smoltification (NKA activity 60%, qRT-PCR 57%). In the third year, all but one site were determined as sea water ready by qRT-PCR but only at 4 by enzymatic testing. On site testing with mobile qRT-PCR was successfully performed on four farm sites. Altogether, high sensitivity was shown for the in lab (98.9%, SE 0.24) and mobile (93.43%, SE 0.119) assays when tested using a quantitative RNA standard. Some indication for obscured smoltification assay results due to environmental increased heavy metal contamination was observed. Our results prove it is possible to test a smoltification marker on site and provide results on the day of testing during the smolt period allowing for informed decisions on seawater transfer.

Participating in Complementary and Integrative Health Approaches Is Associated With Veterans' Patient-reported Outcomes Over Time.

BACKGROUND: Veterans Affairs is dedicated to providing a Whole Health approach to care, including offering complementary and integrative health (CIH) approaches to Veterans. OBJECTIVE: The objective of this study was to examine the association of CIH participation with Veterans' patient-reported outcomes over time. RESEARCH DESIGN: A survey of patient-reported outcomes at 5 timepoints: baseline, 2, 4, 6, and 12 months. SUBJECTS: Veterans participating in any type of CIH approach at 2 Veterans Affairs medical centers. MEASURES: Mixed hierarchical models with repeated variables were used to test the hypothesis that participating in any CIH approach would be associated with Veterans' overall physical/mental health [Patient-Reported Outcomes Measurement Information System 28 (PROMIS 28)], pain intensity, perceived stress (Perceived Stress Scale-4), and engagement in their care (Patient Activation Measure-13), controlling for age, male sex, site, participation in other CIH approaches, and surveys completed. RESULTS: We received 401 surveys from 119 Veterans (72% male, age range: 29-85 y) across all timepoints. Yoga participation was related to decreases in perceived stress (P<0.001), while tai chi participation was associated with improvements in overall PROMIS 28 physical and mental health functioning (P<0.02). Specific types of CIH were associated with significant improvements in PROMIS 28 subscales: meditation participation with physical functioning at 2, 6, and 12 months; tai chi participation with anxiety at 2 and 6 months, and ability to participate in social role activities at 2 months. No CIH approach was associated with Veterans' pain or engagement in their care. CONCLUSION: As specific CIH approaches are associated with improvements in patient-reported outcomes, clinicians, Veterans, and family members may use this information in discussions of nonpharmacological options to address health and well-being.

Effects of increased scrotal temperature on semen quality and seminal plasma proteins in Brahman bulls.

Environmental temperature has effects on sperm quality with differences in susceptibility between cattle subspecies and breeds, but very little is known about the seminal plasma protein (SPP) changes resulting from testicular heat stress. Scrotal insulation (SI) for 48 hr was applied to Brahman (Bos indicus) bulls. Semen was collected at 3-day intervals from before, until 74 days post-SI. The changes in sperm morphology and motility following SI were comparable to previously reported and differences were detected in measures of sperm chromatin conformation as early as 8 days post-SI. New proteins spots, in the SPP two-dimensional (2-D) gels, were apparent when comparing pre-SI with 74 days post-SI, and SPP identified as associated with mechanisms of cellular repair and protection. Similar trends between 2-D gel and Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH-MS) data was observed, with SWATH-MS able to quantify individual SPP that otherwise were not resolved on 2-D gel. The SPP assessment at peak sperm damage (21-24 days) showed a significant difference in 29 SPP (adjusted p < .05), and identified six proteins with change in abundance in the SI group. In conclusion both spermatozoa and SPP composition of bulls are susceptible to temperature change incurred by SI, and SPP markers for testicular heat insults may be detected.

Stakeholder perceptions of components of a Parkinson disease care management intervention, care coordination for health promotion and activities in Parkinson's disease (CHAPS).

BACKGROUND: A recent nurse-led proactive care management intervention, Care Coordination for Health Promotion and Activities in Parkinson Disease (CHAPS), improved care quality when compared to usual care in a randomized controlled trial. Therefore, stakeholder (patient participants, nurse care managers, and Parkinson disease (PD) specialists) perceptions of key intervention components merit evaluation to inform decisions about dissemination. METHODS: This multi-site study occurred in five southwest United States Veterans Health Administration medical centers. Stakeholders were surveyed on their perceptions of CHAPS including the CHAPS Assessment, CHAPS nurse care managers, the Siebens Domain Management Model™ (a practical clinical model), and the Siebens Health Care Notebook (Notebook) (self-care tool). Participants' electronic medical records were abstracted for perceptions of the Notebook. Statistical analysis software was used to provide summary statistics; open card sorting methodology was used to identify themes and attributes in qualitative data including usability of some components. RESULTS: Participants, overall, highly rated their medication self-management, acknowledged some challenges with the CHAPS self-care tools, reported knowledge of PD specialist follow-up and PD red flags, and rated CHAPS nurse care managers as helpful. Nurse care manager responses indicated the CHAPS Assessment and Program highly facilitated care of their patients. Most all PD specialists would refer other patients to CHAPS. Nurse care manager and PD specialist responses indicated improved participant management of their PD. Three themes emerged in participant perceptions of the Notebook: Notebook Assets (e.g., benefits and features-liked); Deferring Notebook Review (e.g., no time to review); and Reasons for Not Using (e.g., participant preference). Shared attributes regarding the Siebens Domain Management Model and Notebook usability, reported by nurse care managers, were user-friendly, person/patient-centered, and organized. Some challenges to their use were also reported. CONCLUSIONS: Overall, stakeholder perceptions of the proactive nurse-led CHAPS intervention indicated its value in the care of individuals with PD. Responses about the CHAPS Assessment, Siebens Domain Management Model, and Notebook self-care tool signified their usefulness. Stakeholders' constructive suggestions indicated their engagement in CHAPS. These findings support CHAPS dissemination and contribute to research in care management. TRIAL REGISTRATION: ClinicalTrials.gov as NCT01532986 , registered on January 13, 2012.

Use of whole-genome sequence data and novel genomic selection strategies to improve selection for age at puberty in tropically-adapted beef heifers.

BACKGROUND: In tropically-adapted beef heifers, application of genomic prediction for age at puberty has been limited due to low prediction accuracies. Our aim was to investigate novel methods of pre-selecting whole-genome sequence (WGS) variants and alternative analysis methodologies; including genomic best linear unbiased prediction (GBLUP) with multiple genomic relationship matrices (MGRM) and Bayesian (BayesR) analyses, to determine if prediction accuracy for age at puberty can be improved. METHODS: Genotypes and phenotypes were obtained from two research herds. In total, 868 Brahman and 960 Tropical Composite heifers were recorded in the first population and 3695 Brahman, Santa Gertrudis and Droughtmaster heifers were recorded in the second population. Genotypes were imputed to 23 million whole-genome sequence variants. Eight strategies were used to pre-select variants from genome-wide association study (GWAS) results using conditional or joint (COJO) analyses. Pre-selected variants were included in three models, GBLUP with a single genomic relationship matrix (SGRM), GBLUP MGRM and BayesR. Five-way cross-validation was used to test the effect of marker panel density (6 K, 50 K and 800 K), analysis model, and inclusion of pre-selected WGS variants on prediction accuracy. RESULTS: In all tested scenarios, prediction accuracies for age at puberty were highest in BayesR analyses. The addition of pre-selected WGS variants had little effect on the accuracy of prediction when BayesR was used. The inclusion of WGS variants that were pre-selected using a meta-analysis with COJO analyses by chromosome, fitted in a MGRM model, had the highest prediction accuracies in the GBLUP analyses, regardless of marker density. When the low-density (6 K) panel was used, the prediction accuracy of GBLUP was equal (0.42) to that with the high-density panel when only six additional sequence variants (identified using meta-analysis COJO by chromosome) were included. CONCLUSIONS: While BayesR consistently outperforms other methods in terms of prediction accuracies, reasonable improvements in accuracy can be achieved when using GBLUP and low-density panels with the inclusion of a relatively small number of highly relevant WGS variants.

Quality and extent of implementation of a nurse-led care management intervention: care coordination for health promotion and activities in Parkinson's disease (CHAPS).

BACKGROUND: A recent nurse-led, telephone-administered 18-month intervention, Care Coordination for Health Promotion and Activities in Parkinson's Disease (CHAPS), was tested in a randomized controlled trial and improved care quality. Therefore, intervention details on nurse care manager activity (types and frequencies) and participant actions are needed to support potential dissemination. Activities include nurse care manager use of a holistic organizing framework, identification of Parkinson's disease (PD)-related problems/topics, communication with PD specialists and care coordination, participant coaching, and participant self-care actions including use of a notebook self-care tool. METHODS: This article reports descriptive data on the CHAPS intervention. The study setting was five sites in the Veterans Affairs Healthcare System. Sociodemographic data were gathered from surveys of study participants (community-dwelling veterans with PD). Nurse care manager intervention activities were abstracted from electronic medical records and logbooks. Statistical analysis software was used to provide summary statistics; closed card sorting was used to group some data. RESULTS: Intervention participants (n = 140) were primarily men, mean age 69.4 years (standard deviation 10.3) and community-dwelling. All received the CHAPS Initial Assessment, which had algorithms designed to identify 31 unique CHAPS standard problems/topics. These were frequently documented (n = 4938), and 98.6% were grouped by assigned domain from the Organizing Framework (Siebens Domain Management Model™). Nurse care managers performed 27 unique activity types to address identified problems, collaborating with participants and PD specialists. The two most frequent unique activities were counseling/emotional support (n = 387) and medication management (n = 349). Both were among 2749 total performed activities in the category Implementing Interventions (coaching). Participants reported unique self-care action types (n = 23) including use of a new notebook self-care tool. CONCLUSIONS: CHAPS nurse care managers implemented multiple activities including participant coaching and care coordination per the CHAPS protocol. Participants reported various self-care actions including use of a personalized notebook. These findings indicate good quality and extent of implementation, contribute to ensuring reproducibility, and support CHAPS dissemination as a real-world approach to improve care quality. TRIAL REGISTRATION: ClinicalTrials.gov as NCT01532986 , registered on January 13, 2012.

How to use saturation monitoring in newborns.

Pulse oximetry is a first-line monitoring tool, used in neonatal medicine routinely as a part of continuous monitoring during intensive care. It is also used to guide response to resuscitation and as a screening tool for congenital heart disease. Despite its widespread use, many healthcare providers are unaware of the underlying principles and limitations of pulse oximetry in neonates. In this article, we will discuss the physiological and technological principles behind the use of saturation monitoring and its use in neonatal practice.

Frontline perspectives on adoption and non-adoption of care management tools for high-risk patients in primary care.

BACKGROUND: Population health management tools (PHMTs) embedded within electronic health records (EHR) could improve management of high-risk patients and reduce costs associated with potentially avoidable emergency department visits or hospitalizations. Adoption of PHMTs across the Veterans Health Administration (VA) has been variable and previous research suggests that understaffed primary care (PC) teams might not be using the tools. METHODS: We conducted a retrospective content analysis of open-text responses (n = 1804) from the VA's 2018 national primary care personnel survey to, 1) identify system-level and individual-level factors associated with why clinicians are not using the tools, and 2) to document clinicians' recommendations to improve tool adoption. RESULTS: We found three themes pertaining to low adoption and/or tool use: 1) IT burden and administrative tasks (e.g., manually mailing letters to patients), 2) staffing shortages (e.g., nurses covering multiple teams), and 3) no training or difficulty using the tools (e.g., not knowing how to access the tools or use the data). Frontline clinician recommendations included automating some tasks, reconfiguring team roles to shift administrative work away from providers and nurses, consolidating PHMTs into a centralized, easily accessible repository, and providing training. CONCLUSIONS: Healthcare system-level factors (staffing) and individual-level factors (lack of training) can limit adoption of PHMTs that could be useful for reducing costs and improving patient outcomes. Future research, including qualitative interviews with clinicians who use/don't use the tools, could help develop interventions to address barriers to adoption. IMPLICATIONS: Shifting more administrative tasks to clerical staff would free up clinician time for population health management but may not be possible for understaffed PC teams. Additionally, healthcare systems may be able to increase PHMT use by making them more easily accessible through the electronic health record and providing training in their use.

Investigation and Management of an Outbreak of Lead Intoxication in an Extensively Managed Beef Herd.

Fifteen hundred 12−15-month-old tropically adapted heifers inadvertently grazed a paddock which had a refuse dump in it containing burnt out vehicle batteries. The cattle grazed this paddock for approximately seven days. Subsequently these cattle were managed as two cohorts (cull and potential replacement breeding animals). Deaths commenced in the cull heifer group approximately 18 days after initial exposure to the refuse dump during relocation to a feedlot. Mortalities continued for 12 days, with other heifers showing clinical signs of marked central nervous system dysfunction requiring euthanasia. Necropsy of several clinically affected cattle plus blood sampling for lead analysis confirmed a diagnosis of lead intoxication. The crude mortality rate in the cull heifers was 6.6% (n = 685). Following confirmation of the diagnosis most of the potential replacement heifers (second cohort) were also relocated to the feedlot. The estimated crude mortality rate in this cohort was 5.8% (n = 815). All possible lead intoxication deaths occurred within 34 days of initial exposure, and apparently after day 16 at the feedlot no further heifers showed any clinical signs which could be attributed to lead intoxication. Longitudinal monitoring of blood lead concentrations was used to identify cattle suitable for slaughter. Overall, 70% of heifers initially blood sampled (n = 1408) had no detectable lead in their blood, however 16% had markedly elevated blood lead concentrations (> 0.7µmol/L) which persisted, and 2% had above the maximum normal threshold 1.5 years later. These latter cattle were subsequently euthanized, and necropsy revealed that visible pieces of lead were still present in the reticulum of several animals. At no time did any of these heifers with persistently high blood lead concentrations show clinical signs of lead intoxication.

Anatomy of the Female Koala Reproductive Tract.

The koala (Phascolarctos cinereus), while being an iconic Australian marsupial, has recently been listed as endangered. To establish an improved understanding of normal reproductive anatomy, this paper brings together unpublished research which has approached the topic from two perspectives: (1) the establishment of an artificial insemination program, and (2) the definition of Chlamydia spp.-derived histopathological changes of the female koala urogenital system. Based on the presentation and histological processing of over 70 opportunistic specimens, recovered from wildlife hospitals in Southeast Queensland (Australia), we describe the gross and microanatomy of the koala ovary, oviduct, uteri, vaginal complex, and urogenital sinus during the interestrous, proliferative, and luteal phases of the reproductive cycle.

The Development of Cutaneous Lesions in Tropically Adapted Beef Cattle Is Associated with Hypersensitive Immune Response to Buffalo Fly Antigens.

This study investigated the role of cattle immune responses in the pathogenesis of buffalo fly (Haematobia irritans exigua) (BF) lesions. Brangus steers phenotyped for lesion development were divided into three groups: high lesion susceptibility (HL), low lesion susceptibility (LL) and no lesions (NL), based on lesion severity scores. Each steer was injected intradermally with different concentrations of BF, Onchocerca gibsoni (Og), and Musca domestica (Md) antigens. At 1 h post-injection, wheal areas at BF injection sites were found to be significantly larger in HL than NL cattle, but there were no significant differences (p < 0.05) found between either the HL or NL cattle and LL cattle. At 24, 48, and 72 h post-injection, the skinfold thickness response to both BF and Md antigens was significantly greater in the HL group than the NL group. However, skin thickness was significantly greater for the BF antigens than the Md antigens (p < 0.05). There were no significant differences found between the LL and NL animals in response to the BF antigens at any time, and no significant differences were determined between any of the lesion groups in response to the Og antigens. Histological examination of skin sections taken from the BF antigen injection sites in HL cattle at 72 h post-injection revealed necrosis of the epidermis and superficial dermis, along with severe eosinophilic inflammation. This study suggests that differences in the hypersensitivity to BF antigens underlie differences amongst the cattle in their susceptibility to the development of BF lesions, and breeding for immune-related biomarkers may assist in selecting more BF lesion-resistant cattle.

Development and application of a new liver pathology recording system for use in cattle abattoirs.

Liver disease in beef cattle has a significant global economic impact on feedlot and abattoir industries due to reduced animal performance, carcase yield, and carcase quality. This study aimed to create a post-mortem data collection tool which could be deployed at chain speed on an abattoir floor, as well as to evaluate pathological findings in both normal and condemned livers from an Australian beef cattle population. The first 1006 livers were used to formulate a user-friendly, high-throughput liver grading tool for use in an abattoir setting and to evaluate the histological features of common liver abnormalities. Subsequently, over 11,000 livers from a Southeast Queensland abattoir were analyzed. The most observed defects in condemned livers were liver abscessation, fibrosis, adhesions, and liver fluke, with histological features similar to previous reports. Bacterial culture was performed in 29 cases of liver abscessation, revealing a different balance of flora to that reported internationally. This study has developed an easy to use, efficient data collection tool that enables rapid, highly detailed assessment of large numbers of beef cattle livers at slaughter. This tool will allow thorough investigation into the effect of liver disease on beef production, in both industry and research contexts.

Bacterial culture and antimicrobial susceptibility results from bovine milk samples submitted to four veterinary diagnostic laboratories in Australia from 2015 to 2019.

A 5-year retrospective study was conducted to describe the mastitis-causing organisms isolated from bovine milk samples submitted to four veterinary diagnostic laboratories in Australia. The aim of this study was to identify temporal, geographical, and seasonal patterns of occurrence for the organisms and report the in vitro susceptibility of the most common mastitis-causing pathogens. In total, 22,102 milk samples were submitted between 2015 and 2019. The results were reported as positive growth for at least one significant organism (n = 11,407; 51.6%), no growth (n = 5,782; 26.2%), and mixed/contaminated growth (n = 4,913; 22.2%). Culture results for no growth, gram-negative bacteria, and eukaryotic organisms were combined for each region, and they were accounted for between 23 and 46% of submissions. These results represent a subset of mastitis cases for which the antibiotic treatment may not be warranted. A total of 11,907 isolates were cultured from 11,407 milk samples. The most common isolated organisms were Streptococcus uberis [41.3%; 95% confidence interval (CI): 40.4-42.1%] and Staphylococcus aureus (23.6%; 95% CI: 22.8-24.3%). For S. uberis and S. aureus, there was an association between a positive culture result and the dairy region. All regions except for the Sub-tropical Dairy region were more likely to culture S. uberis compared to the reference, Dairy NSW (P < 0.001). Similarly, for S. aureus, a positive culture result was more likely in all other dairy regions compared to Dairy NSW (P < 0.001). The LISA cluster analysis identified differences between High-High (hotspot) postcodes for S. aureus and S. uberis throughout all the analyzed dairy regions. These results highlight the need for further investigations into specific risk factors, such as environmental factors and herd-level predictors, which may have influenced the observed regional variations. Common mastitis-causing pathogens showed overall good susceptibility to a range of antimicrobials used in the treatment of mastitis. On-going surveillance of mastitis-causing pathogens and their antimicrobial susceptibilities will facilitate targeted mastitis control and treatment programs.