Husbandry Factors Research Articles

Housing and Husbandry Factors Affecting Zebrafish (Danio rerio) Novel Tank Test Responses: A Global Multi-Laboratory Study.

The reproducibility crisis in bioscience, characterized by inconsistent study results, impedes our understanding of biological processes and global collaborative studies offer a unique solution. This study is the first global collaboration using the zebrafish (Danio rerio) novel tank test, a behavioral assay for anxiety-like responses. We analyzed data from 20 laboratories worldwide, focusing on housing conditions and experimental setups. Our study included 488 adult zebrafish, tested for 5 min, focusing on a variety of variables. Key findings show females exhibit more anxiety-like behavior than males, underscoring sex as a critical variable. Housing conditions, including higher stocking densities and specific feed types, influenced anxiety levels. Optimal conditions (5 fish/L) and nutritionally rich feeds (e.g., rotifers), mitigated anxiety-like behaviors. Environmental stressors, like noise and transportation, significantly impacted behavior. We recommend standardizing protocols to account for sex differences, optimal stocking densities, nutritionally rich feeds, and minimizing stressors to improve zebrafish behavioral study reliability.

Exploring the gut microbiota of healthy captive Asian elephants from various locations in Yunnan, China.

The Asian elephant (Elephas maximus) is a giant herbivore classified as an endangered wildlife species by the International Union for Conservation of Threatened Species.This study aims to investigate and compare the core gut microbiota of captive Asian elephants from three different locations in Yunnan Province, China, to explore the impact of environmental and husbandry factors on microbial diversity. We collected fecal samples from 29 captive Asian elephants from three locations and performed full-length 16S rRNA gene sequencing. Microbial diversity was assessed using alpha diversity (Chao1 and Shannon indexes) and beta diversity (Bray-Curtis and Euclidean distance metrics). Principal coordinate analysis (PCoA) was used to visualize microbial variation among groups. Alpha diversity analysis showed that the microbial diversity in the Yexianggu group was higher than that in the other groups. Bray-Curtis and Euclidean metrics revealed significant differences among the microbial communities. Bacteroidetes and Firmicutes, which are key cellulose-degrading bacteria, were the dominant phyla in all groups. Synergistaceae was the most abundant family in the Menghai group, while Lachnospiraceae and Pirellulaceae were more abundant in the Yexianggu and Yuantongshan groups, respectively. Genus p-1008-a5-gut-group was more abundant in Yexianggu, and Prevotella was predominant in Menghai. These results indicate that habitat and husbandry practices significantly influence the gut microbiota of captive Asian elephants. The identification of bacterial species such as Lactobacillus fermentum, Clostridium neonatale, Enterococcus mundtii, Klebsiella huaxiensis, Corynebacterium nasicanis, and Streptococcus equinus highlights the potential role of specific microbes in maintaining host-microbial interactions. Promoting microbial diversity through improved captive conditions could enhance the health of these endangered animals.

Cryptosporidium infections in asymptomatic calves up to 4 months in Poland: a cross-sectional population study

Cattle cryptosporidiosis is noted worldwide with varied frequency of infection prevalence depending on geographical, environmental and husbandry factors. In this study, the prevalence of Cryptosporidium infections in cattle was determined on the basis of molecular results obtained by testing 1601 faecal samples collected from calves up to 4 months of age housed in all Polish provinces from 2014 to 2018. Detection and identification of Cryptosporidium species was performed at the 18 small subunit ribosomal RNA (18S rRNA) locus by conducting PCR–RFLP analysis of the amplified DNA fragments. The prevalence of Cryptosporidium infections in the cattle population was 45.3% (CI 95%: 42.8–47.7; 725/1601). The infected animals were housed on 233/267 (87.3%) of monitored farms with regional prevalence ranging from 27.8 to 62%. The restriction pattern of 18S rRNA amplicons for positive samples was characteristic of C. parvum, C. bovis, C. ryanae, C. andersoni, and unexpectedly also of C. baileyi and C. suis. Infections of C. bovis and C. ryanae prevailed in the studied cattle population relegating C. parvum to third in prevalence. Likewise, mixed infections caused by C. bovis and C. ryanae as well as C. parvum and C. bovis were observed. A relationship between the infecting parasite species and animal breed was found. For instance, C. parvum prevailed in Black and White lowland breed, C. ryanae in Limousine cattle and C. andersoni in dairy animals of mixed dairy breeds. Furthermore, differences in prevalence of particular parasite species between cattle breeds were also shown.

Cutaneous apocrine gland neoplasia in 16 captive African wild dogs (Lycaon pictus)

This retrospective study documents the occurrence of single and multiple cutaneous apocrine gland tumours (CATs) on the dorsal midline of 16 captive African wild dogs (AWDs, Lycaon pictus) derived from 161 submissions to diagnostic laboratories in South Africa, France and Germany between 1997 and 2022. Animals included in the study came from zoological institutions in South Africa (n = 2), France (n = 5) and Germany (n = 1) and ranged from 5 to 14 years of age. Fifteen affected animals were female (94%) and one was male. CATs presented as raised, hairless, multilobular, grey firm masses, consistently located along the dorsal midline. Apart from a single cutaneous apocrine adenoma and a cystadenoma occurring concurrently with two non-cystic adenocarcinomas, neoplasms were consistent with malignant cutaneous apocrine adenocarcinomas with lymphatic spread and visceral metastases. Advanced age and female sex were identified as risk factors. A genetic component or association with the increasing use of GnRH agonist contraceptives was suspected but could not be established. This study highlights the need for close clinical monitoring of AWDs over the age of 5 years for the development of CATs along the dorsal midline and supports early surgical intervention. More research is needed to determine the role of inbreeding, endocrine changes and husbandry factors that may play a role in the development of CATs on the dorsal midline of AWDs.

The effects of sex, season, and natural sunlight on plasma vitamin D3 levels in two chelonian species (Testudo hermanni, Trachemys scripta) and their interaction with calcium, phosphate, and magnesium as associated plasma compounds

Species specific physiology, seasonal changes, sex, and husbandry factors all influence the blood chemistry of chelonians, including vitamin D3, calcium, phosphate and magnesium levels. Problems in the supply of many of these are commonly seen in captive reptiles. The goal of this study was to measure vitamin D3, calcium, phosphate and magnesium in plasma from captive, healthy, adult Hermann’s tortoises (Testudo hermanni) and pond sliders (Trachemys scripta). Samples were categorized and compared based on species, sex, season, and access to sunlight as a central husbandry element. Blood samples of 522 Hermann’s tortoises and 188 pond sliders, taken from March to September 2022, were included in the study. New reference intervals for vitamin D3, calcium, phosphate and magnesium were established, with specific reference intervals calculated for each species, sex, and season in those cases in which significant differences were found based on these factors. For the calculation of reference intervals for vitamin D3 the factors species, season and access to sunlight were considered. Vitamin D3 levels differed by access to sunlight in some seasons depending on the species and were generally higher in Hermann’s tortoises. Plasma vitamin D3 levels did not correlate with calcium, phosphorus or magnesium levels on a larger scale in either species. Calcium, phosphate, and magnesium were higher in females than in males of both species, and magnesium was higher in Hermann’s tortoises than in pond sliders. Our results can be helpful in a more specific interpretation of blood results and support previous findings that direct sunlight is an important factor in chelonian health. More studies are needed to better understand the role of other hormonal influence on the vitamin D3, calcium, phosphate and magnesium metabolism in chelonians.

Welfare and Management of Civets in Civet Coffee Tourism Plantations

ABSTRACT Civet coffee is produced with coffee beans that have passed through the digestive tract of civets which are then processed for drinking. Outlets, known as civet coffee tourism plantations are popular tourist attractions in Bali, Indonesia. These outlets keep caged civets for public viewing and sell civet coffee. We assessed civet welfare in 29 civet coffee tourism plantations to assess husbandry factors, the five freedoms and body condition scores. We also assessed civet welfare in eight wildlife markets where civets are sourced for civet coffee tourism and calculated turnover of civets. We found 99 civets in civet coffee tourism plantations and 136 in markets, where. Annually between 400 and 800 civets are sold. Welfare standards do not meet the Indonesian laws and regulations. Diet, hygiene, presence of water and mobility affected body condition scores and no civet met all of the five freedoms. Enforcement of welfare and trade laws is needed to improve civet welfare, and to curb the illegal civet trade. Tourists frequenting civet coffee tourism plantations should be made aware of the low welfare standards to inform their choice about supporting this industry.

The role of the veterinary diagnostic toxicologist in apiary health.

Susceptibility of individuals and groups to toxicants depends on complex interactions involving the host, environment, and other exposures. Apiary diagnostic investigation and honey bee health are truly population medicine: the colony is the patient. Here we provide basic information on the application of toxicology to the testing of domestic honey bees, and, in light of recent research, expand on some of the challenges of interpreting analytical chemistry findings as they pertain to hive health. The hive is an efficiently organized system of wax cells used to store brood, honey, and bee bread, and is protected by the bee-procured antimicrobial compound propolis. Toxicants can affect individual workers outside or inside the hive, with disease processes that range from acute to chronic and subclinical to lethal. Toxicants can impact brood and contaminate honey, bee bread, and structural wax. We provide an overview of important natural and synthetic toxicants to which honey bees are exposed; behavioral, husbandry, and external environmental factors influencing exposure; short- and long-term impacts of toxicant exposure on individual bee and colony health; and the convergent impacts of stress, nutrition, infectious disease, and toxicant exposures on colony health. Current and potential future toxicology testing options are included. Common contaminants in apiary products consumed or used by humans (honey, wax, pollen), their sources, and the potential need for product testing are also noted.

Conserved core microbiota in managed and free-ranging Loxodonta africana elephants.

The gut microbiota plays a crucial role in animal health and homeostasis, particularly in endangered species conservation. This study investigated the fecal microbiota composition of European captive-bred African savanna elephants (Loxodonta africana) housed in French zoos, and compared it with wild African savanna elephants. Fecal samples were collected and processed for DNA extraction and amplicon sequencing of the 16S rRNA gene. The analysis of α and β diversity revealed significant effects of factors such as diet, daily activity, and institution on microbiota composition. Specifically, provision of branches as part of the diet positively impacted microbiota diversity. Comparative analyses demonstrated distinct differences between captive and wild elephant microbiomes, characterized by lower bacterial diversity and altered co-occurrence patterns in the captive population. Notably, specific taxa were differentially abundant in captive and wild elephants, suggesting the influence of the environment on microbiota composition. Furthermore, the study identified a core association network shared by both captive and wild elephants, emphasizing the importance of certain taxa in maintaining microbial interactions. These findings underscore the impact of environment and husbandry factors on elephant gut microbiota, highlighting the benefits of dietary enrichment strategies in zoos to promote microbiome diversity and health. The study contributes to the broader understanding of host-microbiota interactions and provides insights applicable to conservation medicine and captive animal management.

The color of fresh pork: Consumers expectations, underlying farm-to-fork factors, myoglobin chemistry and contribution of proteomics to decipher the biochemical mechanisms

The color of fresh pork is a crucial quality attribute that significantly influences consumer perception and purchase decisions. This review first explores consumer expectations and discrimination regarding pork color, as well as an overview of the underlying factors that, from farm-to-fork, contribute to its variation. Understanding the husbandry factors, peri- and post-mortem factors and consumer preferences is essential for the pork industry to meet market demands effectively. This review then delves into current knowledge of pork myoglobin chemistry, its modifications and pork discoloration. Pork myoglobin, which has certain peculiarities comparted to other meat species, plays a weak role in determining pork color, and a thorough understanding of the biochemical changes it undergoes is crucial to understand and improve color stability. Furthermore, the growing role of proteomics as a high-throughput approach and its application as a powerful research tool in meat research, mainly to decipher the biochemical mechanisms involved in pork color determination and identify protein biomarkers, are highlighted. Based on an integrative muscle biology approach, the available proteomics studies on pork color have enabled us to provide the first repertoire of pork color biomarkers, to shortlist and propose a list of proteins for evaluation, and to provide valuable insights into the interconnected biochemical processes implicated in pork color determination. By highlighting the contributions of proteomics in elucidating the biochemical mechanisms underlying pork color determination, the knowledge gained hold significant potential for the pork industry to effectively meet market demands, enhance product quality, and ensure consistent and appealing pork color.

A case study assessing the impact of mating frequency on the reproductive performance of the Hawaiian bobtail squid Euprymna scolopes

BackgroundThe symbiosis between the Hawaiian bobtail squid Euprymna scolopes and bacterium Vibrio fischeri serves as a model for investigating the molecular mechanisms that promote the initial formation of animal-bacterial symbioses. Research with this system frequently depends on freshly hatched E. scolopes, but the husbandry factors that promote hatchling production in a mariculture facility remain underreported. Here we report on the reproductive performance of E. scolopes in response to decreased mating frequency.ResultsOne animal cohort was maintained in a mariculture facility for 107 days, with females assigned to either a control group (mating once every 14 days) or an experimental group (mating once every 21 days). No differences between the groups were observed in survival, the number of egg clutches laid, or hatchling counts. Each group featured multiple females that were hyper-reproductive, i.e., they generated more than 8 egg clutches while in captivity. Examination of the distributions for daily hatchling counts of individual egg clutches revealed significant variation in the hatching patterns among clutches that was independent of mating frequency. Finally, an assessment of hatchling production showed that 93.5% of total hatchlings produced by the cohort were derived from egg clutches laid within the first 70 days.ConclusionsThese results suggest a lower mating frequency does not impede hatchling production. Furthermore, the variation in hatchling production among egg clutches provides new insight into the reproductive performance of E. scolopes as a lab animal for microbiology research.

Risk factors for summer mortality in greenlip abalone (Haliotis laevigata) and hybrid abalone (H. laevigata × Haliotis rubra): A case-control study

In Australian aquaculture, abalone mortality during warm water temperatures has been termed summer mortality. Summer mortality likely involves complex interactions between biological, environmental, husbandry and nutritional factors; however, this is poorly understood. In this study, we conducted a case-control study for farmed greenlip abalone (Haliotis laevigata) and hybrid abalone (H. laevigata × Haliotis rubra) to identify risk factors associated with summer mortality. Farm mortality data from 2015 to 2021 were used to identify tanks which fit the case definition and tanks that did not. We constructed a model to predict summer mortality risk using logistic regression and forward variable selection. Modelling considered 61 potential risk factors (examples included water quality, husbandry, climate, biology). The final selected model including six main effects and five two-way interactions. Except for maximum water temperature in the week prior to the case/control date, all parameters selected in the final model were involved in one or more interactions. The model identified interactions between age and each of previous year summer mortality, size when removed from weaning tanks and feed rate. There were also interactive effects of previous year summer mortality and size when removed from weaning tanks, and of feed rate and post-grading mortality. The risk of summer mortality was two times more likely for every 2 °C increase in maximum weekly water temperature. Post-grading mortality was associated with an increased risk of summer mortality, but relative risk decreased at higher feed rates. Risk of summer mortality in younger abalone increased with higher feed rates, while increasing feed rates for 30-month abalone had no effect on the risk of summer mortality. Abalone in tanks which experienced summer mortality the previous year were at a higher risk of summer mortality regardless of age. For abalone that did not experience summer mortality the year prior, the subsequent risk of summer mortality increased with abalone age. Improved understanding of summer mortality risk factors may help guide management strategies and future research to advance abalone aquaculture.

Prevalence of LA-MRSA in pigsties: analysis of factors influencing the (De)colonization process

Professional pig husbandry is often associated with a more or less high load of LA-MRSA. Possible risk factors for LA-MRSA colonization in pig herds have already been identified in studies suggesting that housing conditions may affect LA-MRSA prevalence. In Europe, pigs are kept under variety of conditions. The aim of this study is to identify husbandry and housing condition factors that affect colonization with LA-MRSA. 78 pig farms were selected and assigned to three categories according to housing conditions: conventional, alternative and organic. Animal and surface samples were taken and examined for the presence of LA-MRSA at beginning and end of one fattening period per farm. Altogether, a significant (p < 0.05) decrease in colonization with LA-MRSA from beginning to end of the fattening periods in pigs and surfaces can be observed. Alternative farms showed a higher dynamic in the colonization. In organic farms, almost no colonization was found. Influencing housing condition factors that determine LA-MRSA status at the end of the fattening period are the number of pigs in the building, LA-MRSA status at the beginning of fattening period, material of the floor (straw bedding), strictness of black–white separation and antibiotic treatment during the fattening period. For pig farming in general, knowledge and measures to reduce the colonization with LA-MRSA would be important.

Equine blood cultures: Can we do better?

Blood culture is considered the gold standard test for documenting bacteraemia in patients with suspected bacterial sepsis in veterinary and human medicine. However, blood culture often fails to yield bacterial growth even though the clinical picture is strongly suggestive of bacterial sepsis, or contaminating organisms can overgrow the true pathogen, making accurate diagnosis and appropriate management of this life-threatening condition very challenging. Methodology for collecting blood cultures in equine medicine, and even in human hospitals, is not standardised, and many variables can affect the yield and type of microorganisms cultured. Microbiological culture techniques used in the laboratory and specific sample collection techniques, including volume of blood collected, aseptic technique utilised, and the site, timing and frequency of sample collection, all have substantial impact on the accuracy of blood culture results. In addition, patient-specific factors such as husbandry factors, the anatomical site of the primary infection, and changing microflora in different geographic locations, also can impact blood cultures. Thus, blood cultures obtained in practice may not always accurately define the presence or absence of, or specific organisms causing, bacteraemia in horses and foals with suspected sepsis. Erroneous blood culture results can lead to inappropriate antimicrobial use, which can result in poor outcomes for individual patients and contribute to the development of antimicrobial resistance in the patient's microflora and the environmental microcosm. This review summarises current indications and methodology, and specific factors that may be optimised, for equine blood culture, with particular focus on available literature from neonatal foals with suspected bacterial sepsis. To standardise and optimise blood culture techniques in horses and foals, future research in this area should be aimed at determining the optimal volume of blood that should be collected for culture, and the ideal site, timing, and frequency of sample collection.

Blue sheep strongly affect snow leopard relative abundance but not livestock depredation in the Annapurna Conservation Area, Nepal

Large carnivores play key roles in their ecosystems, but their protection is a major challenge in biodiversity conservation due to conflicts with human interests. The snow leopard ( Panthera uncia ) is the top predator of Asian high-altitude landscapes and faces various threats including wild prey depletion and illegal killings as a consequence of livestock depredation. As the interactions between snow leopards, wild prey, and livestock are still insufficiently understood, we studied the effects of 1) wild prey (blue sheep Pseudois nayaur and Himalayan marmots Marmota himalayana ) and domestic prey on snow leopard relative abundance, and of 2) these ecological parameters and intervention applications on livestock depredation by snow leopards. In the Annapurna Conservation Area, Nepal, we monitored wildlife populations and livestock along transects (490.8 km) in 82 grid cells (4 ×4 km) in 2019 and 2021 and conducted questionnaire surveys to determine livestock depredation between 2018 and 2021 (n = 479 households). We applied generalized linear models (GLMs) and sample comparison testing to examine the effects of prey densities and other environmental and anthropogenic predictors on snow leopard relative abundance and livestock depredation. Blue sheep density strongly positively affected snow leopard relative abundance, which also increased with terrain ruggedness and decreased with increasing densities of livestock and the human population. The size of livestock holdings shaped depredation events of large livestock (yak, cattle and horse), whereas depredation events of sheep and goats, which accounted for most (68.6%) depredated animals, decreased with increasing human population density and marmot presence. The strong impact of blue sheep on snow leopard relative abundance supports demands for integrating this ungulate into conservation and management plans, including wild prey recovery and translocation. The rather weak evidence for effects of blue sheep on depredation events suggests that conflicts over livestock depredation by snow leopards would neither be inflicted nor solved by increasing wild prey abundance. This demonstrates the need to improve intervention strategies in the Annapurna region, such as predator-proofing corrals and optimizing daytime herding practices. We suggest further exploring the effects of marmots and other secondary prey on livestock depredation rates, and testing the suitability of additional interventions, e.g., dogs and deterrents, as conflict mitigation tools. Our results will support wildlife managers in setting conservation priorities to promote the long-term co-existence of local people and snow leopards. • Blue sheep strongly shape snow leopard relative abundance in the Annapurna region. • Livestock losses in the Annapurna region are mainly associated with husbandry factors. • Wild prey restoration and improved husbandry practices should benefit snow leopards.

Physiological responses of red seabream ( Pagrus major ) to stress and rearing temperature

The stress physiology and welfare needs of red seabream, a fish species with high nutritional and economic value for aquaculture, have been poorly studied. The aim of the current study was to investigate physiological responses of red seabream to potential environmental and husbandry stress factors. We quantified the acute stress response of fish exposed to a standardized acute chasing stress protocol as well as to transportation stress, by analysing acute stress biomarkers such as plasma concentrations of cortisol, glucose, lactate and osmolality. Moreover, the physiological status of fish reared at different water temperatures (15, 20 and 25°C) was also studied by analysing plasma parameters and cortisol concentration in scales. Results showed that in most estimated parameters, red seabream showed a fast response and recovery to acute stress. On the contrary, recovery after an 18-h transportation stress was prolonged and required more than one day. Finally, rearing of fish at different temperatures also affected stress indicators such as plasma cortisol and glucose, while lactate and osmolality were not significantly affected. Regarding cortisol concentration in fish scales, a chronic stress indicator, results showed that fish reared at 15°C had a significantly higher cortisol concertation of scales than those exposed to 25°C. The data provide a better insight into the effect of husbandry and environmental factors on red sea bream stress physiology and welfare.

Patterns of livestock depredation by snow leopards and effects of intervention strategies: lessons from the Nepalese Himalaya

Context Large carnivores are increasingly threatened by anthropogenic activities, and their protection is among the main goals of biodiversity conservation. The snow leopard (Panthera uncia) inhabits high-mountain landscapes where livestock depredation drives it into conflicts with local people and poses an obstacle for its conservation. Aims The aim of this study was to identify the livestock groups most vulnerable to depredation, target them in implementation of practical interventions, and assess the effectiveness of intervention strategies for conflict mitigation. We present a novel attempt to evaluate intervention strategies for particularly vulnerable species, age groups, time, and seasons. Methods In 2020, we conducted questionnaire surveys in two regions of the Annapurna Conservation Area, Nepal (Manang, n = 146 respondents and Upper Mustang, n = 183). We applied sample comparison testing, Jacobs’ selectivity index, and generalised linear models (GLMs) to assess rates and spatio-temporal heterogeneity of depredation, reveal vulnerable livestock groups, analyse potential effects of applied intervention strategies, and identify husbandry factors relevant to depredation. Key results Snow leopard predation was a major cause of livestock mortality in both regions (25.4–39.8%), resulting in an estimated annual loss of 3.2–3.6% of all livestock. The main intervention strategies (e.g. corrals during night-time and herding during daytime) were applied inconsistently and not associated with decreases in reported livestock losses. In contrast, we found some evidence that dogs, deterrents (light, music playing, flapping tape, and dung burning), and the use of multiple interventions were associated with a reduction in reported night-time depredation of yaks. Conclusions and implications We suggest conducting controlled randomised experiments for quantitative assessment of the effectiveness of dogs, deterrents, and the use of multiple interventions, and widely applying the most effective ones in local communities. This would benefit the long-term co-existence of snow leopards and humans in the Annapurna region and beyond.

Analysis of the types of animal husbandry and planting that influence household biogas in rural China

Producing biogas from agricultural waste by using a household biogas digester has a critical role in increasing energy supply and reducing greenhouse gas emissions in rural areas. However, only a few studies have analyzed the type of animal husbandry and planting that influence household biogas. This paper analyzes the spatial-temporal distribution of household biogas and its proportion in the total biogas produced in rural China from 2009 to 2018. The correlation between household biogas in rural China and animal husbandry and planting from 2009 to 2018 is also examined. The types of animal husbandry and planting that influence household biogas are then respectively determined via ordinary least squares and geographically weighted regression. Results show that the spatial-temporal distributions of household biogas with maximum and minimum values of 1.384 × 1010 m3 in 2011 and 0.8420 × 1010 m3 in 2018, respectively and its proportion with maximum and minimum values of 94.83% in 2009 and 75.07% in 2018, respectively significantly vary and show a declining trend from 2009 to 2018. The number of cattle and pigs is identified as the main animal husbandry factor that influences household biogas, whereas the planting areas of vegetables, fiber, and tobacco were identified to be the main planting factors. Considering fitting effects, R2 and adjusted R2 values of 0.8620 and 0.8100 obtained by geographically weighted regression respectively, were higher than those of ordinary least squares (0.6480 and 0.6220, respectively), respectively in animal husbandry factors, whereas R2 and adjusted R2 values of 0.8400 and 0.7990 obtained by geographically weighted regression, respectively, were higher than those of ordinary least squares (0.7190 and 0.6880, respectively) in planting factors. These results provide a reference for planning the production of biogas and the utilization of agricultural waste.

Demographic, Husbandry, and Biosecurity Factors Associated with the Presence of Campylobacter spp. in Small Poultry Flocks in Ontario, Canada.

This study is part of a 2 year disease surveillance project conducted to establish the prevalence of poultry and zoonotic pathogens, including Campylobacter spp., among small poultry flocks in Ontario, Canada. For each post-mortem submission to the Animal Health Laboratory, a pooled sample of cecal tissue was cultured for Campylobacter spp., and a husbandry and biosecurity questionnaire was completed by the flock owner (n = 153). Using both laboratory and questionnaire data, our objective was to investigate demographic, husbandry, and biosecurity factors associated with the presence of Campylobacter spp. in small flocks. Two multivariable logistic regression models were built. In the farm model, the odds of Campylobacter spp. were higher in turkeys, and when birds were housed in a mixed group with different species and/or types of birds. The odds were lower when antibiotics were used within the last 12 months, and when birds had at least some free-range access. The effect of pest control depended on the number of birds at risk. In the coop model, the odds of Campylobacter spp. were lower when owners wore dedicated clothing when entering the coop. These results can be used to limit the transmission of Campylobacter spp. from small poultry flocks to humans.

Prevalence of metatarsal growth plate lesions in Swiss fattening bulls

The prevalence of osteochondral changes in the metatarsal growth plates of fattening bulls was investigated. Plantarodorsal radiographic views of the metatarsal region of 204 hind legs from 102 slaughtered fattening bulls were taken. Radiographic lesions in metatarsal growth plates were confirmed in selected cases using computed tomography (n=14) and histology (n=6). Radiographic criteria for growth plate lesions were axis deviations between the metatarsal bones and the digit, radiolucencies in the growth plate, increased bone density in the metaphysis, irregularities of the growth plate and marginal osteophytes («lipping»). The individual lesions were categorised as present/absent or 1 = slight, 2 = distinct, and 3 = severe. A weighted sum of these radiographic changes was generated for each growth plate and for each animal, and used for statistical analysis of the associations between husbandry factors and the occurrence of lesions. Almost all of the metatarsal bones had signs of osteochondral changes on the radiographs of the growth plates. The most common lesions were lipping (99,5 %), increased bone density in the metaphysis (66,6 %) and radiolucencies in the growth plates (64,1 %). Computed tomography and histology revealed hyperplasia of the margins of the epiphysis and metaphysis, focal increase in bone deposits accompanied by incomplete ossification and irregular and widened cartilage columns of the growth plate. There were statistically significant associations between the weighted radiographic changes and slaughter weight, average daily weight gain, husbandry practices and production label. The prevalence of radiographic lesions indicative for osteochondrosis of the metatarsal growth plates of fattening bulls slaughtered at a local abattoir was high. The extent to which the distinct and severe lesions are associated with reduced production and obvious clinical lameness requires further study.

Assessing Allostatic Load in Ring-Tailed Lemurs (Lemur catta).

Simple SummaryOur ability to measure and understand chronic stress in animals is limited by animals’ inability to communicate to us their perception of stressors. Researchers have developed tools to measure stress in animals, but these tools have many limitations. A novel measurement of chronic stress using several biomarkers has been studied in humans and great apes, but no research has assessed this tool in other primates, including lemurs. Our aim was to determine the relationship between allostatic load index (ALI), a measurement of chronic stress, and individual, social, medical and husbandry factors that may impact stress in lemurs housed under human care. Smaller group sizes, a higher percentage of time spent indoors, and more frequent group changes were associated with a higher ALI, indicating that these factors may be associated with chronic stress and potential deleterious health effects. This research presents support for ALI as a tool to help us better understand and mitigate stress in animals under our care.Responses to stress are unavoidable, adaptive mechanisms in humans and non-human animals. However, in humans, chronic stress has been linked to poor health outcomes and early mortality. Allostatic load, the physiologic dysregulation that occurs when an organism is exposed to chronic stressors, has been used to assess stress in humans; less work has been done using non-human primates. Our aim was to determine the relationship between allostatic load in ring-tailed lemurs (Lemur catta) under human care and potentially stressful individual, social, medical and husbandry factors, as well a sex and age. An allostatic load index (ALI) was calculated for 38 lemurs using six biomarkers measured in serum (albumin, cortisol, dehydroepiandrosterone-sulfate, DNA damage, glucose and prostaglandin E2). Potentially stressful factors were recorded over the lifetime of each lemur using medical and husbandry records. Animals with a higher percentage of time spent indoors, those kept in smaller average group sizes, and those with fewer minor group composition changes had, or tended to have, higher ALI. There was no relationship between ALI and sex or age. Some social and husbandry factors were associated with allostatic load in lemurs, indicating that this index may be a useful tool in assessing and determining factors contributing to stress of lemurs and other animals under human care.