Irish Veterinary Journal最新文献

Background: Biosecurity measures are essential to prevent the introduction and spread of pathogens within (internal biosecurity) and between (external biosecurity) broiler farms. Implementing effective biosecurity practices not only protects animal health but also enhances productivity, welfare, and farm sustainability in general. This study assesses the temporal trends in biosecurity scores in Irish broiler farms from 2019 to 2023 using the Biocheck.UGent tool and identifies areas for improvement. The analysis includes data from 403 broiler farms, as well as recommendations provided by private veterinary practitioners (PVPs) to enhance biosecurity.

Results: The results show an overall upward trend in biosecurity scores over the study period. Internal biosecurity scores were consistently higher than external scores. Median internal scores increased from 60 (over 100) in 2019 to 75 in 2023 (P < 0.05). External scores increased from 50 to 65 in the same period (P < 0.05). Farms that underwent at least three assessments showed increases in median total scores of roughly 10 points after the first visit (P < 0.05). However, certain biosecurity categories, particularly cleaning and disinfection with medians over years remaining below 70, received consistently low scores despite frequent recommendations for improvement by the PVPs.

Conclusions: The findings suggest that, while progress has been made, further efforts are needed to enhance biosecurity practices, particularly in areas with persistent low scores, such as depopulation of broilers and cleaning and disinfection. PVPs should provide more targeted recommendations for these categories and support farmers in effectively implementing these practices.

Neonatal weak calf syndrome (NWCS) is characterized by reduced vigour in neonatal calves, leading to difficulties in standing and suckling. This study aimed to evaluate whether serum selenium and Vitamin E (VE) concentrations were associated with NWCS. The study included 29 indigenous Korean (Hanwoo) beef calves: 10 healthy and 19 weak (14 surviving, 5 non-surviving), based on standing and suckling ability. These calves were recruited from 19 farms. Healthy calves suckled an adequate volume of colostrum while weak calves (who suckled inadequately) were fed 1-2 L of frozen colostrum or colostrum replacer; all within 2 h of birth. One blood sample was collected from each calf at least 4 h after last feeding (within 18 h after birth), and serum selenium and VE concentrations were analysed. The results showed no significant difference in serum selenium concentrations between healthy and weak calves but, VE concentrations were significantly lower (and deficient) in weak calves. Among the weak calves, non-survivors also showed numerically lower levels than survivors. These findings suggest an association between calf blood VE concentrations and NWCS but not with calf blood selenium concentrations. It is hypothesised that the NWCS was caused by foetal VE deficiency as despite additional colostrum feeding weak calves (NWCS) still had significantly lower postcolostral serum VE concentrations than healthy calves. As VE is involved in muscle function, immunity, and oxidative stress regulation, ensuring adequate maternal VE supplementation and timely colostrum intake may help reduce both the impact of VE deficiency on NWCS and the impact of NWCS on VE status in calves with low maternal-foetal VE reserves where prompt colostrum feeding is not practised, as is often the case with beef calves.

Background: Bovine tuberculosis (bTB), caused primarily by Mycobacterium bovis, remains a major challenge across the island of Ireland. Despite decades of an eradication programme that encompasses cattle testing, movement restrictions, and badger culling, bTB prevalence has increased in recent years. The epidemiology of bTB is complex, with inter-species (e.g. badger-cattle) and intra-species (e.g. cattle-cattle) transmission of infection. This study utilised whole-genome sequencing (WGS) to investigate the genetic diversity and spatial distribution of M. bovis across the island of Ireland as a route to help elucidate transmission of infection.

Results: A total of 5,875 M. bovis isolates from cattle and badgers were analysed to identify strain diversity, geographic clustering, and patterns of strain sharing within and between host species. Our findings reveal significant regional variation in strain distribution, with certain clades predominantly confined to specific regions, while others are more widely dispersed. Strong genetic similarities between cattle and badger isolates support the role of badgers as infection reservoirs. Furthermore, a subset of herds contained multi-strain infections and amongst these herds there were 'controlled finishing units' (CFUs), where infection was more likely driven by inward cattle movements than local transmission.

Conclusions: By integrating phylogenetic analysis with spatial mapping and cattle movement data, this study provides new insights into M. bovis transmission pathways and highlights the value of WGS in refining Ireland's bTB control strategies.

Anaplasma is an obligate intracellular bacterium that cause anaplasmosis. The two species of Anaplasma namely Anaplasma marginale and Anaplasma centrale affects cattle, buffaloes, sheep, goats and wild ruminants. This rickettsial microorganism, which is transmitted by ticks, is causing massive economic losses due to weight loss, decreased milk supply, severe anemia and high mortality. The research study was conducted between May 2023 to April 2024 to determine the prevalence, symptomatic analysis of anaplasmosis and associated study of milk reduction in cattle from district Nowshera, KP, Pakistan. Total 635 blood specimens were obtained from different cattle herds coming from 17 farms. Such blood specimens underwent microscopic examination by using Giemsa-stained blood smears and troughs molecular analysis by PCR targeting the msp1b gene (265 bp fragment) in order to detect A. marginale. All relevant statistical analyses, including Chi-square tests, were carried out with SPSS to test for significance (p < 0.05). Combining microscopy and PCR, the overall prevalence of A. marginale was determined to be 13.3% (n = 85) and 12.7% (n = 81) respectively. Age-wise prevalence revealed that younger cattle (< 5 years) had significantly higher infection rates 62.3% (n = 53) as compared to older cattle (> 5 years) 37.6% (n = 32), with a p-value of 0.037. Of the PCR-positive cases, 64.1% (n = 52) were from younger cattle and 35.8% (n = 29) were from older cattle. A potential cause for the relatively low PCR positivity in comparison to microscopic identification is that certain false-positive microscopic identifications based on Heinz bodies or other blood artifacts as Anaplasma species may be involved. Naturally, PCR would only target the genetic material of the actual disease. Microscopy showed that prevalence peaked in the month of July at 24.7%, while PCR recorded peak prevalence in June at 33.3%. There were no confirmed cases in January and February, confirming that the differences in seasonal prevalence were statistically significant (p < 0.05). In terms of production loss, one-year-old Holstein cows experienced a 47% reduction in milk yield post-infection (from 17 L to 9 L), while cows 2 to 7 years-old exhibited reductions ranging from 50 to 75%, all statistically significant. It was concluded that anaplasmosis was widely distributed in district Nowshera and it is high economic losses on dairy farm. Further research is needed to develop control measures and to improve understanding of the disease transmission.

Accurate diagnosis of Bovine Tuberculosis (bTB) in cattle is important for success of eradication programmes, but the current reliance on the single intradermal comparative cervical tuberculin (SICCT) test is not achieving disease eradication in all jurisdictions, including Northern Ireland (NI). In this study, a novel Phagomagnetic separation (PhMS)-qPCR assay to rapidly detect viable Mycobacterium bovis in bovine blood samples was evaluated. A total of 149 heart blood samples were collected from cattle at exsanguination point of the slaughter line at a NI abattoir between June and August 2023 - 74 from TB reactor cattle (compulsorily culled within days of a positive SICCT test result) and 75 from routine slaughter cattle (< 30 months). Peripheral blood mononuclear cells (PBMCs) were isolated and lysed to release any mycobacteria present before PhMS-qPCR and culture were performed to detect presence of viable M. bovis. The DNAs obtained were subsequently tested for evidence of viable Mycobacterium avium subsp. paratuberculosis (MAP) also. PhMS-qPCR results indicate that of the TB reactor cattle with conclusive PhMS-qPCR results, 7.5% of bloods tested positive for viable M. bovis only, 41.8% for viable MAP only and 28.4% showed evidence of co-infection (both M. bovis and MAP detected). Of the routine slaughter cattle with conclusive PhMS-qPCR results, 22.4% of bloods tested positive for viable M. bovis only, 19.4% for viable MAP only and 20.9% showed evidence of co-infection. Of the blood samples with conclusive culture results, 19.6% TB reactors and 25.4% routine slaughter cattle were M. bovis culture positive. No agreement was observed between the M. bovis PhMS-qPCR assay and M. bovis culture results (Kappa - 0.028, 95% CI -0.162 to 0.105). Results of this study provide proof-of-concept that the PhMS-qPCR assay is able to detect viable M. bovis in bovine blood, although a different qPCR assay with greater detection sensitivity will need to be identified going forward. A surprisingly high number of M. bovis/MAP co-infections were detected in the blood of NI cattle, which may be contributing to failure of the bTB eradication scheme. The latter warrants further investigation.

Background: Since the abolition of EU milk quotas in 2015, the Irish dairy industry has expanded with a 16.6% increase in calf births since 2011. Calf losses have major implications for the economic viability and sustainability of dairy enterprises. There is a paucity of literature on mortality in calves from birth to six months, particularly at a national herd level. Previous studies have tended to focus on herd size as a risk factor for calf mortality rather than the possible influence of herd expansion. The purpose of this study is to quantify any association between dairy herd expansion and the risk of being classified as a high or low calf mortality herd based on analysis of national dairy herd identification and movement records in Ireland from 2016-2020.

Results: In calves aged under 6 months, herds that expanded > 20% (OR 1.23 95% CI: 1.10-1.37, p < 0.001) and > 45% (OR 1.22, 95% CI:1.09-1.36, p = 0.001), were more likely to have > 10% herd calf mortality, compared to herds that did not increase in size. Newly established herds were more likely to have poor mortality outcomes (OR 2.44, 95% CI: 1.82-3.29, p < 0.001) compared to herds that did not increase in size. Herd expansion < 20% was not associated with mortality outcome. Herd ordinal location and herd size were significant risk factors for > 10% herd calf mortality.

Conclusion: This study has demonstrated that herds that have expanded > 20% over five years and newly established herds were more likely to have poor mortality outcomes. It suggests that new entrants into dairy farming may benefit from targeted emphasis on herd health management. The results also highlight the value of national data as a tool to determine optimisation of farm interventions and surveillance and policy decisions to prioritise animal health and welfare.