Acta Veterinaria Scandinavica最新文献

{"title":"Investigation, management and control of a maedi outbreak in Norway in 2019-2020.","authors":"Grim Rømo, Johan Åkerstedt, Anne Bang Nordstoga, Anniken Jerre Borge, Helene Wisløff, Britt Gjerset, Siv Klevar, Mette Valheim, Irene Skei Mjømen, Elisabeth Schei-Berg, Synnøve Vatn, Annette Hegermann Kampen","doi":"10.1186/s13028-024-00749-7","DOIUrl":"10.1186/s13028-024-00749-7","url":null,"abstract":"<p><strong>Background: </strong>Visna-maedi is a notifiable disease in Norway, and eliminating the disease is a national goal. The import of sheep into Norway is very limited, and strict regulations apply to the movement of small ruminants between flocks and within defined geographical regions. Several outbreaks have occurred in the last 50 years, and the most recent before 2019 occurred in Trøndelag county in Central Norway in 2002. A national surveillance programme for small ruminant lentivirus infection exists since 2003.</p><p><strong>Results: </strong>In 2019, the national surveillance programme detected seropositive animals for small ruminant lentivirus in a sheep flock in Trøndelag. Based on the result of polymerase chain reaction analysis and histopathological findings, the Norwegian Food Safety Authority concluded the diagnosis of maedi. Further investigations detected maedi in eight additional sheep flocks in the same county. The flocks were placed under restrictions, and the authorities also imposed restrictions on 82 contact flocks. Sequencing of partial gag genes indicated that the virus in the current outbreak was related to the small ruminant lentivirus detected in the same area between 2002 and 2005.</p><p><strong>Conclusions: </strong>The outbreak investigation shows the need for sensitive and specific diagnostic methods, and an improved and more targeted surveillance strategy. It also demonstrates the risk of disease spreading between flocks through animal movements, and highlights the importance of biosecurity and structured livestock trade. In addition to allowing livestock trade only from flocks documented free from maedi, it may be necessary to monitor sheep flocks over many years, when aiming to eliminate maedi from the Norwegian sheep population.</p>","PeriodicalId":7181,"journal":{"name":"Acta Veterinaria Scandinavica","volume":"66 1","pages":"28"},"PeriodicalIF":1.9,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11225221/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141533370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Congenital syndromic Chiari-like malformation (CSCM) in Holstein cattle: towards unravelling of possible genetic causes.","authors":"Joana Goncalves Pontes Jacinto, Anna Letko, Irene Monika Häfliger, Cord Drögemüller, Jørgen Steen Agerholm","doi":"10.1186/s13028-024-00752-y","DOIUrl":"10.1186/s13028-024-00752-y","url":null,"abstract":"<p><strong>Background: </strong>Chiari malformation type II (CMII) was originally reported in humans as a rare disorder characterized by the downward herniation of the hindbrain and towering cerebellum. The congenital brain malformation is usually accompanied by spina bifida, a congenital spinal anomaly resulting from incomplete closure of the dorsal aspect of the spinal neural tube, and occasionally by other lesions. A similar disorder has been reported in several animal species, including cattle, particularly as a congenital syndrome. A cause of congenital syndromic Chiari-like malformation (CSCM) in cattle has not been reported to date. We collected a series of 14 CSCM-affected Holstein calves (13 purebred, one Red Danish Dairy F1 cross) and performed whole-genome sequencing (WGS). WGS was performed on 33 cattle, including eight cases with parents (trio-based; group 1), three cases with one parent (group 2), and three single cases (solo-based; group 3).</p><p><strong>Results: </strong>Sequencing-based genome-wide association study of the 13 Holstein calves with CSCM and 166 controls revealed no significantly associated genome region. Assuming a single Holstein breed-specific recessive allele, no region of shared homozygosity was detected suggesting heterogeneity. Subsequent filtering for protein-changing variants that were only homozygous in the genomes of the individual cases allowed the identification of two missense variants affecting different genes, SHC4 in case 4 in group 1 and WDR45B in case 13 in group 3. Furthermore, these two variants were only observed in Holstein cattle when querying WGS data of > 5,100 animals. Alternatively, potential de novo mutational events were assessed in each case. Filtering for heterozygous private protein-changing variants identified one DYNC1H1 frameshift variant as a candidate causal dominant acting allele in case 12 in group 3. Finally, the presence of larger structural DNA variants and chromosomal abnormalities was investigated in all cases. Depth of coverage analysis revealed two different partial monosomies of chromosome 2 segments in cases 1 and 7 in group 1 and a trisomy of chromosome 12 in the WDR45B homozygous case 13 in group 3.</p><p><strong>Conclusions: </strong>This study presents for the first time a detailed genomic evaluation of CSCM in Holstein cattle and suggests an unexpected genetic and allelic heterogeneity considering the mode of inheritance, as well as the type of variant. For the first time, we propose candidate causal variants that may explain bovine CSCM in a certain proportion of affected calves. We present cattle as a large animal model for human CMII and propose new genes and genomic variants as possible causes for related diseases in both animals and humans.</p>","PeriodicalId":7181,"journal":{"name":"Acta Veterinaria Scandinavica","volume":"66 1","pages":"29"},"PeriodicalIF":1.9,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11229497/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141533369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergence of Capnocytophaga canimorsus and Capnocytophaga cynodegmi in oral cavities of newborn puppies, a pilot study.","authors":"Kristiina Suominen, Silja Åvall-Jääskeläinen, Inka Sallinen, Anna-Maija Virtala, Joanna Koort","doi":"10.1186/s13028-024-00751-z","DOIUrl":"10.1186/s13028-024-00751-z","url":null,"abstract":"<p><p>Capnocytophaga canimorsus and Capnocytophaga cynodegmi are commensal bacteria in the oral cavities of dogs. Both are zoonotic pathogens that could infect humans via dog bites. C. canimorsus may cause life-threatening infections in humans, whereas C. cynodegmi infections tend to be milder and more localized. Capsular serovars A-C of C. canimorsus seem to be virulence-associated. Some of the C. canimorsus serovars described to date can also be detected in other Capnocytophaga species, including C. cynodegmi. The objective of this pilot study was to investigate the emergence of C. canimorsus and C. cynodegmi after birth in oral cavities of puppies and to evaluate the impact of the dam's Capnocytophaga spp. carrier status on the emergence. Ten litters, altogether 59 puppies, were included in the study. The puppies and their dams were sampled at five time points over seven weeks after whelping. Oral swab samples taken were investigated for the presence of C. canimorsus and C. cynodegmi by species-specific polymerase chain reaction (PCR), the specificity of which was verified by sequencing a selection of the PCR products. Samples that were positive in Capnocytophaga PCR reactions were also capsular-typed by PCR to gain more knowledge about the Capnocytophaga spp. present in the samples. Altogether 10.2% and 11.9% of puppies, or 20.0% and 30.0% of litters tested PCR-positive for C. canimorsus and C. cynodegmi, respectively. Capnocytophaga PCR-positive puppy samples were always positive for only C. cynodegmi or C. canimorsus, not both. Most Capnocytophaga PCR-positive puppies became positive at the age of 5 to 7 weeks. Only a minority (5/16) of the C. cynodegmi PCR-positive dog samples were positive in capsular typing PCR, whereas all C. canimorsus PCR-positive dog samples were negative in capsular typing PCR. For all Capnocytophaga PCR-positive puppies, their dam was positive for the same Capnocytophaga species. These results suggest that puppies become colonized by C. cynodegmi or C. canimorsus from their dams at the time of deciduous teeth eruption.</p>","PeriodicalId":7181,"journal":{"name":"Acta Veterinaria Scandinavica","volume":"66 1","pages":"26"},"PeriodicalIF":1.9,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11218291/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141490495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphomolecular identification of heavy parasitic typhlitis in layer flocks: tissue response and cell-mediated reaction.","authors":"Mohamed A El-Saied, Marwa M Attia, Marwa A Ibrahim, Mohamed Elaish, Mohamed R Mousa","doi":"10.1186/s13028-024-00748-8","DOIUrl":"10.1186/s13028-024-00748-8","url":null,"abstract":"<p><strong>Background: </strong>Heterakis gallinarum (H. gallinarum) is a common poultry parasite that can be found in the ceca of many gallinaceous bird species, causing minor pathology and reduced weight gain. Most infections go unnoticed in commercial flocks due to the dependence on fecal egg counts, which are prone to false-negative diagnoses. Furthermore, there is a lack of research on gastrointestinal nematodes that use molecular identification methods, which could be essential for rapid diagnosis and developing efficient control approaches. As a result, the study aimed to look at the cause of mortality in layer chickens induced by H. gallinarum in Egyptian poultry farms using morphological, ultrastructural, and molecular characterization. Histopathological, immunohistochemical, and cell-mediated immune responses from damaged cecal tissues were also examined.</p><p><strong>Results: </strong>Seventy bird samples from ten-layer flocks of different breeds (Native, white, and brown layers) suffering from diarrhea, decreased egg output, and emaciation were collected. Cecal samples were collected from affected and non-affected birds and were examined for parasitic diseases using light and a scanning electron microscope. The mitochondrial cytochrome oxidase 1 (COX1) gene was used to characterize H. gallinarum. Our results showed that the collected nematodal worms were identified as H. gallinarum (male and female), further confirmed by COX1 gene amplification and sequence alignment. Gene expression analysis of the inflammatory markers in infected tissues showed a significant up-regulation of IL-2, IFN-γ, TLR-4, and IL-1β and a significant down-regulation of the anti-inflammatory IL-10. The mRNA level of the apoptotic cas-3 revealed apoptotic activity among the H. gallinarum samples compared to the control group.</p><p><strong>Conclusions: </strong>Our results implemented the use of molecular methods for the diagnosis of Heterakis, and this is the first report showing the tissue immune response following infection in layers: upregulation of IL-1β, IFN-γ, Il-2, and TLR-4, while down-regulation of anti-inflammatory IL-10 in cecal tissue, Cas-3 apoptotic activity and Nuclear factor-κB (NF-κB)activity with immunophenotyping of T-cells in Heterakis infected tissue.</p>","PeriodicalId":7181,"journal":{"name":"Acta Veterinaria Scandinavica","volume":"66 1","pages":"27"},"PeriodicalIF":1.9,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11221110/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141490496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of forelimb gait variation overground at a walk in sound and lame dogs using a combination of diagnostic techniques.","authors":"Miriam Kjörk Granström, Lars Roepstorff, Kjerstin Pettersson, Ingrid Ljungvall, Maria Dimopoulou, Charlie Peck, Annika Bergström","doi":"10.1186/s13028-024-00746-w","DOIUrl":"10.1186/s13028-024-00746-w","url":null,"abstract":"<p><strong>Background: </strong>Kinetic and kinematic gait analysis is increasingly practised as a part of lameness evaluation in dogs. The aim of this study was to examine the normal short- and long-term variation in forelimb gait in sound control dogs (CD) at a walk using seven selected variables of objective kinetic and kinematic gait analyses. Also, to compare the findings in CD to a group of forelimb lame dogs with elbow osteoarthritis (OAD). An additional aim was to test a kinetic based graphic method for lameness detection; symmetry squares (SS). A prospective longitudinal study was carried out on client owned CD and OAD. Clinical and orthopaedic evaluations were performed to ensure soundness and detect and grade lameness. Seven kinetic and kinematic variables and SS were tested for lameness evaluation. The CD were divided into two subgroups, CD1 and CD2, and examined twice: CD1 with two months interval and CD2 with 3-4 h interval. The OAD group was evaluated once and compared to the CD groups' first examination.</p><p><strong>Results: </strong>Thirteen CD and 19 OAD were included. For CD1 and CD2, there were no significant differences in any examined variable between examination occasions. Total peak force/impulse symmetry and fore-hind peak force/impulse symmetry differed significantly between OAD and CD. Symmetry squares had a 74% agreement to subjective orthopaedic evaluations.</p><p><strong>Conclusions: </strong>In CD, no difference in the examined variables was seen between examination occasions. Four out of seven objective variables differed significantly between CD and OAD. The graphic SS method might have diagnostic potential for lameness detection, making it possible to detect a shift from lame to non-lame limbs. Potentially, this might be especially helpful in bilaterally lame dogs, which often represent a clinical challenge in lameness evaluation.</p>","PeriodicalId":7181,"journal":{"name":"Acta Veterinaria Scandinavica","volume":"66 1","pages":"25"},"PeriodicalIF":1.9,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11191351/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141431119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of vatinoxan in rats sedated with a combination of medetomidine, midazolam and fentanyl.","authors":"Emily Lindh, Anna Meller, Marja Raekallio","doi":"10.1186/s13028-024-00744-y","DOIUrl":"10.1186/s13028-024-00744-y","url":null,"abstract":"<p><strong>Background: </strong>Alpha2-adrenoceptor agonists (α₂-agonists) are widely used in animals as sedatives and for pre-anaesthetic medication. Medetomidine has often been given subcutaneously (SC) to rats, although its absorption rate is slow and the individual variation in serum drug concentrations is high via this route. In addition, α₂-agonists have various effects on metabolic and endocrine functions such as hypoinsulinaemia, hyperglycaemia and diuresis. Vatinoxan is a peripherally acting α₂-adrenoceptor antagonist that, as a hydrophilic molecule, does not cross the blood-brain barrier in significant quantities and thus alleviates peripheral cardiovascular effects and adverse metabolic effects of α₂-agonists. Aim of this study was to evaluate the effects of vatinoxan on sedation, blood glucose concentration, voiding and heart and respiratory rates and arterial oxygen saturation in rats sedated with subcutaneous medetomidine, midazolam and fentanyl.</p><p><strong>Results: </strong>Onset of sedation and loss of righting reflex occurred significantly faster with vatinoxan [5.35 ± 1.08 (mean ± SD) versus 12.97 ± 6.18 min and 6.53 ± 2.18 versus 14.47 ± 7.28 min, respectively]. No significant differences were detected in heart and respiratory rates and arterial oxygen saturation between treatments. Blood glucose concentration (18.3 ± 3.6 versus 11.8 ± 1.2 mmol/L) and spontaneous urinary voiding [35.9 (15.1-41.6), range (median) versus 0.9 (0-8.0) mL /kg/min] were significantly higher without vatinoxan.</p><p><strong>Conclusions: </strong>Acceleration of induction of sedation, alleviation of hyperglycaemia and prevention of profuse diuresis by vatinoxan may be beneficial when sedating rats for clinical and experimental purposes with subcutaneous medetomidine, midazolam and fentanyl.</p>","PeriodicalId":7181,"journal":{"name":"Acta Veterinaria Scandinavica","volume":"66 1","pages":"23"},"PeriodicalIF":2.1,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11141047/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141186217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biophysical properties of alveolar surfactant in drever dogs with hunting associated pulmonary edema.","authors":"Sanna Johanna Viitanen, Sabrine Moya Gehani, Anni Maria Tilamaa, Minna Marjaana Rajamäki, Ruud Anthonius Wilhelmus Veldhuizen","doi":"10.1186/s13028-024-00745-x","DOIUrl":"10.1186/s13028-024-00745-x","url":null,"abstract":"<p><strong>Background: </strong>A syndrome of acute non-cardiogenic pulmonary edema associated with hunting is prevalent in the drever breed, but etiology of this syndrome is currently unknown. Alveolar surfactant has a critical role in preventing alveolar collapse and edema formation. The aim of this study was to investigate, whether the predisposition to hunting associated pulmonary edema in drever dogs is associated with impaired biophysical properties of alveolar surfactant. Seven privately owned drever dogs with recurrent hunting associated pulmonary edema and seven healthy control dogs of other breeds were included in the study. All affected dogs underwent thorough clinical examinations including echocardiography, laryngeal evaluation, bronchoscopy, and bronchoalveolar lavage (BAL) as well as head, neck and thoracic computed tomography imaging to rule out other cardiorespiratory diseases potentially causing the clinical signs. Alveolar surfactant was isolated from frozen, cell-free supernatants of BAL fluid and biophysical analysis of the samples was completed using a constrained sessile drop surfactometer. Statistical comparisons over consecutive compression expansion cycles were performed using repeated measures ANOVA and comparisons of single values between groups were analyzed using T-test.</p><p><strong>Results: </strong>There were no significant differences between groups in any of the biophysical outcomes of surfactant analysis. The critical function of surfactant, reducing the surface tension to low values upon compression, was similar between healthy dogs and affected drevers.</p><p><strong>Conclusions: </strong>The etiology of hunting associated pulmonary edema in drever dogs is not due to an underlying surfactant dysfunction.</p>","PeriodicalId":7181,"journal":{"name":"Acta Veterinaria Scandinavica","volume":"66 1","pages":"24"},"PeriodicalIF":2.1,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11143697/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141183335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occurrence of gastrointestinal nematodes in lambs in Norway, as assessed by copromicroscopy and droplet digital polymerase chain reaction","authors":"Maiken Gravdal, Ian David Woolsey, Lucy Jane Robertson, Johan Höglund, Christophe Chartier, Snorre Stuen","doi":"10.1186/s13028-024-00743-z","DOIUrl":"https://doi.org/10.1186/s13028-024-00743-z","url":null,"abstract":"Gastrointestinal nematodes (GINs) have a major impact on sheep production, health, and welfare worldwide. Norway is no exception, but there are only a few studies on the prevalence of GINs in Norwegian sheep. The aim of this study was to investigate the current occurrence of the most important nematodes in sheep flocks in Norway. Faecal samples were collected from flocks in 2021/2022, mainly from three geographical regions in Norway, i.e., northern, eastern, and western. In each of 134 flocks included, individual samples from 10 lambs (autumn) were pooled. Third stage larvae (L3) were cultivated and harvested (Baermann method) from the pooled samples. The DNA was then extracted and further analysed using droplet digital PCR (ddPCR). This enables assessment of the proportions of the three most important nematode species/genera, i.e., H. contortus, T. circumcincta, and Trichostrongylus. The fractional abundance/relative proportion of each species/genus was assessed by performing duplex assays with universal strongyle and species/genus-specific primers and probe sets. In addition, the occurrence of Nematodirus eggs was assessed by standard faecal egg counts (i.e., McMaster method). Of the 134 flocks sampled, 24 were from the northern region, 31 from eastern, and 71 from western Norway. In addition, some flocks from central (n = 7), and southern (n = 1) Norway were included. Among the sampled flocks, T. circumcincta occurred most commonly (94%), followed by H. contortus (60%) and Trichostrongylus (55%), and Nematodirus (51%). In general, mixed infections were observed, with 38% and 18% of flocks infected with three or all four genera, respectively. The results of this study indicate that GINs are widespread in Norway. Teladorsagia circumcincta seems to be present in most flocks based on this screening. Moreover, the results show that Nematodirus spp. infect lambs throughout the country, predominantly N. battus, and indicate that this nematode has become more abundant, which could lead to an increase in nematodirosis.","PeriodicalId":7181,"journal":{"name":"Acta Veterinaria Scandinavica","volume":"35 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141147588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing the effects of contact duration on cow and calf performance beyond separation - a prospective cohort study.","authors":"Johanne Sørby, Ingrid Hunter Holmøy, Ane Nødtvedt, Sabine Ferneborg, Julie Føske Johnsen","doi":"10.1186/s13028-024-00741-1","DOIUrl":"10.1186/s13028-024-00741-1","url":null,"abstract":"<p><strong>Background: </strong>Consumers, the industry, and many farmers have shown increased interest in alternative management systems that allow for cow-calf contact (CCC) and this topic has become an important focus of research for a sustainable dairy industry. Among the many knowledge gaps still existing in this novel research field, there is a need for further research to investigate effects of CCC beyond the nursing period (i.e., after cow-calf separation). Moreover, multi-herd observational studies are scarce. Therefore, the aim of this study was to investigate the within-herd effect of CCC on machine milk yield and calf growth beyond separation. In this prospective cohort study, we studied all cows and their calves (Norwegian Red breed) born between September 1st 2021 and January 31th 2022 at three Norwegian dairy farms, investigating the impact of CCC on machine milk yield and calf average daily gain (ADG) after separation of the cow-calf pair. The follow-up period was 305 d for cows and six months for calves. Machine milk yield was automatically registered at each milking and calf heart girth was measured once a month. As various contact durations emerged, they were categorized into three groups: no contact (NC 0-3 d), short duration (4-30 d) and long duration (> 30 d). Data were analyzed with linear mixed models with the individual animal as the unit of interest. For cows, days in milk (DIM) from date of separation up to 305 DIM were included in the analysis as a continuous variable. For calves, age up to 195 d was used in the statistical analysis.</p><p><strong>Results: </strong>We found no differences in machine milk yield after separation across the different contact groups: cows with no contact (n = 28), short duration (n = 51) and long duration (n = 27) of contact, all exhibited comparable milk yields from the time of separation until the end of lactation. Furthermore, in the case of calves, no disparities in average daily gain (ADG) were identified for any of the contact groups: calves with no contact (n = 39), short duration (n = 61) and long duration (n = 38) of contact, displayed comparable growth during the first six months of life.</p><p><strong>Conclusions: </strong>Our findings indicate no negative effects of CCC on machine milk yield after separation, nor any sustained effects on calf growth under the conditions of this study. More multi-herd observational studies conducted on-farm is needed to expand the understanding of effects of CCC on cow and calf performance after separation.</p>","PeriodicalId":7181,"journal":{"name":"Acta Veterinaria Scandinavica","volume":"66 1","pages":"21"},"PeriodicalIF":2.1,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11110400/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141080270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacteriophage-derived endolysins as innovative antimicrobials against bovine mastitis-causing streptococci and staphylococci: a state-of-the-art review.","authors":"Niels Vander Elst","doi":"10.1186/s13028-024-00740-2","DOIUrl":"10.1186/s13028-024-00740-2","url":null,"abstract":"<p><p>Bacteriophage-encoded endolysins, peptidoglycan hydrolases breaking down the Gram-positive bacterial cell wall, represent a groundbreaking class of novel antimicrobials to revolutionize the veterinary medicine field. Wild-type endolysins exhibit a modular structure, consisting of enzymatically active and cell wall-binding domains, that enable genetic engineering strategies for the creation of chimeric fusion proteins or so-called 'engineered endolysins'. This biotechnological approach has yielded variants with modified lytic spectrums, introducing new possibilities in antimicrobial development. However, the discovery of highly similar endolysins by different groups has occasionally resulted in the assignment of different names that complicate a straightforward comparison. The aim of this review was to perform a homology-based comparison of the wild-type and engineered endolysins that have been characterized in the context of bovine mastitis-causing streptococci and staphylococci, grouping homologous endolysins with ≥ 95.0% protein sequence similarity. Literature is explored by homologous groups for the wild-type endolysins, followed by a chronological examination of engineered endolysins according to their year of publication. This review concludes that the wild-type endolysins encountered persistent challenges in raw milk and in vivo settings, causing a notable shift in the field towards the engineering of endolysins. Lead candidates that display robust lytic activity are nowadays selected from screening assays that are performed under these challenging conditions, often utilizing advanced high-throughput protein engineering methods. Overall, these recent advancements suggest that endolysins will integrate into the antibiotic arsenal over the next decade, thereby innovating antimicrobial treatment against bovine mastitis-causing streptococci and staphylococci.</p>","PeriodicalId":7181,"journal":{"name":"Acta Veterinaria Scandinavica","volume":"66 1","pages":"20"},"PeriodicalIF":2.1,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11106882/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141069732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}