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Occurrence and distribution of left ventricular bands and normal anatomical features in 78 feline hearts
Get PDFIntroduction/Objectives: Left ventricular bands (LVBs) are common in feline hearts. Their importance and general features are incompletely described. This study aimed to characterize LVBs in feline hearts based on anatomical location, quantity, histological features, and attachment sites. Animals, Materials and Methods: Hearts from 78 domestic cats with or without heart disease were included in this study. Cardiac weight and dimensions were measured, and LVBs were categorized as singular bands or nets, with further characterization by location, length, appearance, and histological examination of attachment sites. Results: Median cardiac weight was 4.34 g/kg (interquartile range: 2.1 g/kg). Left ventricular bands were present in all hearts, with 11% having only singular bands, 32% containing only nets, and 42% having nets covering the entire left ventricle (LV). The most common LVB attachment sites were the LV mid-region involving the posterior papillary muscle. Nets were most common in the mid-region including the papillary muscles (93%), followed by basilar (60%) and apical (59%) regions. All LVBs contained collagen, myocytes, adipose tissue, endothelial cells, and fibroblasts. No excess fibrosis, myocardial hypertrophy, or endocardial thickening at the attachment sites was identified. Study Limitations: The study included mainly domestic stray cats aged 12 weeks to 15 years, with few purebred or diseased individuals. The hearts were examined by one person, which may introduce subjectivity. Conclusions: Left ventricular bands are commonly found in the mid LV section of feline hearts, primarily involving the posterior papillary muscle, suggesting normal variation. Left ventricular bands contain myocytes, not Purkinje fibers, and are not fibrous tendons. Myocyte hypertrophy or excess fibrosis is absent at attachment sites. 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Plant genotype-specific modulation of Clonostachys rosea-mediated biocontrol of septoria tritici blotch disease in wheat
Get PDFBackground Beneficial microorganisms can act as biological control agents (BCAs) directly by targeting pathogens or indirectly by enhancing the plant's defense mechanisms against pathogens. However, efficiencies with which plants benefit from BCAs vary, potentially because of genetic variation in plants for plant-BCA compatibility. The aim of this study was to explore the genetic variation in winter wheat for modulation of Clonostachys rosea-mediated biocontrol of septoria tritici blotch disease caused by the fungal pathogen Zymoseptoria tritici. Results In total, 202 winter wheat genotypes, including landraces and old cultivars grown from 1900 onwards in the Scandinavian countries, were tested under greenhouse-controlled conditions. Foliar spray applications of the pathogen and the fungal BCA in two treatments, i.e., Z. tritici (Zt) alone and Z. tritici along with C. rosea (ZtCr) were used to assess the disease progress over time. The absence and presence of C. rosea in Zt and ZtCr, respectively, allowed the dissection of variation for plant disease resistance and biocontrol efficacy. The study showed significant (P < 0.05) phenotypic variation among plant genotypes for disease progression in both Zt and ZtCr treatments. Moreover, the application of C. rosea resulted in a significant (P < 0.05) reduction in disease progression for seven genotypes and increased disease progression for eleven genotypes, indicating a plant genotype-dependent effect on the interaction between wheat, C. rosea and Z. tritici. For the phenotypic variation in disease progress and biocontrol efficacy, a genome-wide association study using a 20K single-nucleotide polymorphism (SNP) marker array was also performed. In total, five distinct SNP markers associated with disease resistance and four SNP markers associated with C. rosea biocontrol efficacy were identified. Conclusions This work serves as a foundation to further characterize the genetic basis of plant-BCA interactions when inoculated with Z. tritici, facilitating opportunities for simultaneous breeding for disease resistance and biocontrol efficacy
Dairy farm management factors associated with clinical observations in young dairy calves sold at auction markets in Québec, Canada: A cross-sectional study
Get PDFIn Québec, Canada, nonreplacement calves are generally sent at a young age to auction markets to be sold for veal or dairy beef production. Various clinical observations found during the calves' journey, either at an auction market or on arrival at a calf raiser farm, have been associated with increased risk of morbidity, such as dehydration or umbilical problems. The objective of this cross-sectional study was to quantify associations between calf raising management strategies at the dairy farm level and clinical observations at auction markets during sale. For this purpose, during 8 different sale days, the 2 largest auction markets in Québec were visited, and all calves sold on those days were systematically examined. The number of clinically relevant findings (CRF) present per calf (among presence of umbilical cord, wet umbilical area, umbilical pain, umbilical swelling, persistent cervical skin fold ≥2 s, sunken eyes, eye or nasal discharge, ear drop, limb anomaly, emaciation or dirty hide) was recorded. After the sale, farm owners were contacted to answer a specific questionnaire on calf management. The total number of CRF from all sold calves from the same farm (dependent variable) was modeled using Poisson multivariable regression, with questionnaire answers as potential covariates and the number of calves sold per farm during the observation period as an offset. The questionnaire was completed during a standardized phone call and focused on farm characteristics and characteristics of calves sold, including calving management, calf care at birth, nutrition, housing, and transportation. A total of 3,656 calves from 1,349 different sellers were examined. The questionnaire information was obtained from 409 different farms representing 847 calves. The median number of calves sold per farm was 2 (range: 1–19). The umbilical cord was visually present in 376 calves (44%). Among the most commonly observed CRF, eye discharge (n = 290, 34%), umbilical swelling (n = 144, 17%), and presence of dehydration signs (persistent cervical skin fold ≥2 s [n = 111, 13%] or sunken eyes [n = 83, 9.8%]) were the most commonly reported anomalies. According to the final multivariable Poisson regression model, the incidence rate ratio (IRR) of CRF for farms that sold calves at a mean age 10 d (IRR = 1.21, 95% CI: 1.04–1.41). The IRR was also higher for farms that did not give colostrum to calves within 1 h following birth compared with calves receiving colostrum within 1 to 2 h (IRR = 1.73, 95% CI: 1.24–2.49), 2 to 6 h (IRR = 1.48, 95% CI: 1.06–2.14) and more than 6 h (IRR = 1.59, 95% CI: 1.06–2.44) after birth. The IRR were higher for farms using milk replacer to feeding sold calves versus raw milk (IRR = 1.2, 95% CI: 1.06–1.37) and higher for farms where calves typically receive their last meal >3 h before transportation to the auction market versus calves receiving their last mea
Exploring structural changes in the Swedish cattle population and between-holding movements
Get PDFMovements of livestock between holdings plays an important role in the spread of many infectious diseases, and network analysis can provide a greater understanding of potential spread dynamics. This study explored cattle movements between Swedish holdings from 2005 to 2022 to enhance the knowledge basis for epidemiological analyses. In addition to classical network analysis, a novel method, Location Change Pattern (LCP), was used to analyse movements between holdings per individual. Furthermore, survival analysis was used to investigate animal- and herd level risk factors associated with moving cattle from a holding. Although the number of cattle and holdings decreased, the number of movements increased substantially over the study period. Simultaneously, the network became more disassortative with an increased average path length, whilst indegree and in- and outgoing contact chains decreased. Combined, the results suggests that an epidemic spread in the cattle population may be slower and reach a smaller final size compared to 2005. Additionally, the clustering coefficient and reciprocity increased over time which might change the dynamics of disease spread. The increase in movements can be partly explained by an increased number of cattle being moved back and forth between holdings, particularly seen for female cattle. Male calves at holdings with a high proportion of female cattle had the greatest hazard of being moved, with an increased hazard at around 20 days of age. In summary, significant changes over time were found in the cattle population and in the movement network, which must be accounted for when working with disease prevention
Suckling and allosuckling behavior of dairy calves in indoor dam-rearing systems
Get PDFAn important element in dairy cow-calf contact (CCC) systems is to ensure sufficient milk intake by calves. However, little is known about possible changes in suckling behavior during suckling periods for calves up to 15 weeks old, and the prevalence of allosuckling is poorly understood in the context of these systems. This research had two aims: first, to explore possible changes in suckling behavior as calves aged when housed in an indoor CCC system, and second, to identify calf-level factors associated with allosuckling. Both aims were independently investigated in two separate studies (cow- and calf-driven contact, respectively) and involved both Swedish Red and Swedish Holstein dams and calves. In the cow-driven study, dam-calf pairs (n = 19 male and female calves) had shared access to a separate contact area containing stalls, which dams could leave at any time. In the calfdriven study, calves (n = 24 female calves) could access their dams (n = 23) in all parts of the pen, except the milking area. Behavior sampling from video was used to record suckling behaviors during a 24-h period at average calf ages of 3, 6, 9, 12 (both studies) and 15 (cow-driven only) weeks. In the cow-driven study, calves behaved consistently across all weeks in terms of suckling bout length and frequency. Calves in the calf-driven study took significantly fewer, but longer, suckling bouts as they aged. The overall frequency of allosuckling observed in the cow-driven study (36%) was higher than that in the calf-driven study (14%). However, the odds of allosuckling increased significantly with increasing calf age in both studies. Calves in the cow-driven study were observed to allosuckle even in the presence of their own dam, and increasingly so as they aged. For both studies, instances of allosuckling were over 140 times more likely when other calves were already engaged in suckling on a cow. We conclude that allosuckling is likely to occur in indoor dam-rearing systems when the animals are housed in automatic milking systems, although the frequency will depend on the age of the calves and the presence of other suckling calves
Translocations associated with colour-sidedness are common in northern Swedish cattle breeds
Get PDFThe Swedish Mountain cattle and four other native Swedish cattle breeds show the phenotype of colour-sidedness. The causes of this phenotype are either a translocation and duplication from chromosome 6 to chromosome 29 (known as Cs29) including the KIT gene, or an additional translocation allele where part of Cs29 has been translocated back to chromosome 6 (Cs6). Besides the colour-sidedness, the Cs29 translocation has been associated with gonadal hypoplasia which can cause fertility problems. Despite breeding efforts during more than 80 years to reduce the prevalence of gonadal hypoplasia, there are still individuals with gonadal hypoplasia. We genotyped the Cs29 and Cs6 alleles in Swedish Mountain cattle and five other Swedish native breeds. Whole-genome sequence data of 30 cattle were analysed for the translocations, and 115 DNA samples were analysed using multiplex PCR. The current allele frequency of the Cs29 allele in Swedish mountain cattle was estimated to be 44%. The results indicate that the Cs29 translocation is also present in the four other native Swedish cattle breeds with colour-sidedness, and the Cs6 translocation in at least three of them
Local epidemiology, impact and human response during an African swine fever outbreak in a rural village in Northern Uganda
Get PDFThis study investigated local epidemiology, impact and actions taken by smallholder pig farmers during an outbreak of African swine fever (ASF) in rural Uganda. Data collection included the biological sampling of sick or dead pigs, structured interviews using a questionnaire and geospatial records of risk locations for ASF. Following confirmation of the presence of ASF virus by conventional PCR, all households that reported pig deaths were considered ASF positive. Data analysis used descriptive statistics and content analysis of questionnaire data. The spatial distribution of positive households, risk locations for ASF and pig populations were analysed using a hexagonal grid; retrospective space-time permutation was used to detect spatio-temporal clusters. Of the 128 pigkeeping households in the study village, 61 ASF positive households were identified. Out of these, 43 reported selling and 34 consuming dead pigs. Three households reported disposing of carcasses in a safe way (in a latrine or by burning). The pig population in the ASF positive households was reduced by 48 %, compared to a reduction of 2 % in the ASF negative households. The reduction in pig population was spatially interconnected on a hexagonal level and associated with high pig density hexagons at the start of the outbreak and with the presence of risk locations for ASF (trading centres, pork restaurants and slaughter slabs). Two significant spatio-temporal outbreak clusters were detected. The opportunities to study ASF in smallholder settings in the immediate temporal connection to outbreaks are rare and the study gave unique insights that deepen the epidemiological and social understanding of ASF in the smallholder context
Sequencing airborne DNA to monitor crop pathogens and pests
Get PDFCrop pests and diseases increasingly challenge the global food system. To prepare for and detect outbreaks, surveillance plays an important role. Traditional monitoring methods are often organism-specific, making large-scale monitoring of crop pathogens and pests impractical. We here investigate the potential for using shotgun sequencing of airborne eDNA for large-scale surveillance of crop pathogens and pests. We show that it is possible to detect DNA from all types of organisms in air, and that DNA can be classified down to species level. However, the accuracy of the identification is highly dependent on the quality of reference genomes of both the pathogens or pests, and their close relatives present in the region. Finally, we find that observed degree of crop damages correlate with amount of DNA from crop pathogens and pests in air, showing the promise of this approach for surveillance of all types of crop pathogens and pests