Prevalence of pathogens causing subclinical mastitis in 15 dairy herds in the Republic of Ireland

<p/> <p>Milk samples from 285 cows in 15 dairy herds were collected for bacteriological analysis. Cows were selected on the basis of a somatic cell count (SCC) exceeding 200,000 cells per ml at the three most recent milk recordings prior to sampling. <it>Staphylococcus aureus </it>and <it>Streptococcus uberis </it>were the predominant isolates accounting for 21% (n = 61) and 19% (n = 53) of isolates, respectively. <it>Streptococcus uberis </it>was more frequently isolated from split-calving herds than from spring-calving herds and this difference was statistically significant (P < 0.005). Herds with suboptimal housing had a significantly greater prevalence of <it>S. uberis </it>than did herds where housing was adequate (P < 0.005). The isolation rates for <it>S. aureus </it>was significantly greater in herds where parlour hygiene was suboptimal (P < 0.05).</p

Ear, tail and skin lesions vary according to different production flows in a farrow-to-finish pig farm

peer-reviewedBackground Pig performance and risk of disease are associated with production flow. Given the link between health and welfare, it is likely that animal welfare indicators are also associated with production flow. This study investigated the association between production flow and tail, ear and skin lesions on a farm with a purported ‘all-in/all-out’ policy. This was an observational study whereby pigs were managed according to routine farm practice. A total of 1,016 pigs born within 1 week from the same batch were followed through the production stages and the presence or absence of welfare indicators was recorded at 4, 7, 9, 12, 16 and 24 weeks of age. Three production flows were retrospectively identified: flow 1 = ‘normal’ pigs that advanced through the production stages together ‘on time’, flow 2 = pigs delayed from advancing from the 1st to the 2nd nursery stage by 1 week and flow 3 = pigs delayed from advancing through the production stages by > 1 week. A nested case control design was applied by matching pigs by sow parity, number of born alive and birth weight. Results The presence of ear lesions was 4.5 less likely in pigs in flow 2 and 2.9 times less likely in pigs in flow 3 (P < 0.001) compared to pigs in flow 1. Pigs in flow 3 were 2.2 more likely to have tail and 1.6 times more likely to have ear lesions (P < 0.001) compared to pigs in flow 2. Pigs in flow 2 were less likely to have tail lesions compared with pigs in flow 1 (P < 0.05). Differences between production flows for the risk of skin lesions varied according to age (P < 0.05). Conclusion All production flows were associated with a high risk of lesions which raises concerns for pig welfare. However, risks for ear, tail and skin lesions varied according to each production flow likely due to the specific management practices inherent to each flow. Results from this study could be used to modify existing management practices, thus leading to improvements in animal welfare and possibly performance in intensive pig systems

Removing prophylactic antibiotics from pig feed: how does it affect their performance and health?

peer-reviewedBackground Antibiotics (AB) are an important tool to tackle infectious disease in pig farms; however some research indicates that their frequent mis/over-use may contribute to the development of antibiotic resistance and the WHO has declared that this issue should be addressed. Little is known about the long term consequences of withdrawing prophylactic AB from pig feed; hence we aimed to assess its effects on performance and health of pigs from weaning to slaughter. Six batches of 140 pigs each were monitored on a commercial farm through the weaner and finisher stages to slaughter. In-feed antibiotics were not added to the feed for half of the pigs (NOI) and were added in the other half (ABI) within each batch for the whole weaner stage. Individual pigs in both treatments were treated with parenteral administrations if and when detected as ill or lame. Productive performance, parenteral treatments and mortality were recorded on farm and the presence of respiratory disease was recorded at slaughter. Pen was considered the experimental unit. Results ABI pigs showed higher growth (P = 0.018) and feed intake (P = 0.048) than NOI pigs in the first weaner stage but feed efficiency was not affected (NOI = 1.48 vs. ABI = 1.52). Despite an initial reduction in performance, NOI pigs had similar performance in finisher stage (ADG: NOI = 865.4 vs. ABI = 882.2) and minimal effects on health compared to ABI pigs. No difference between treatments was found at the abattoir for the percentage of pigs affected by pneumonia, pleurisy, pleuropneumonia and abscesses (P > 0.05). Mortality rate was not affected by treatment during the weaner stage (P = 0.806) although it tended to be slightly higher in NOI than ABI pigs during the finisher stage (P = 0.099). Parenteral treatments were more frequent in NOI pigs during the weaner stage (P <  0.001) while no difference was recorded during the finisher stage (P = 0.406). Conclusions These data suggest that the removal of prophylactic in-feed antibiotics is possible with only minor reductions in productive performance and health which can be addressed by improved husbandry and use of parenteral antibiotics

Early life indicators predict mortality, illness, reduced welfare and carcass characteristics in finisher pigs

peer-reviewedThe objective of this study was to investigate associations between early life indicators, lactation management factors and subsequent mortality, health, welfare and carcass traits of offspring. A total of 1016 pigs from a batch born during one week were used. During lactation, number of liveborn piglets, stillborn and mummies, sow parity, number of times cross-fostered, weaning age, birth and weaning body weight (BW) were collected. Mortality was recorded throughout the offspring production cycle. Prior to slaughter, pigs were scored for lameness (1 = non-lame to 3 = severely lame). At slaughter, tail lesions were scored (0 = no lesion to 4 = severe lesion) and cold carcass weight (CCW), lean meat%, presence of pericarditis and heart condemnations were recorded. Additionally, lungs were scored for pleurisy (0 = no lesions to 4 = severely extended lesions) and enzootic pneumonia (EP) like lesions. There was an increased risk of lameness prior to slaughter for pigs born to first parity sows (P < 0.05) compared with pigs born to older sows. Sow parity was a source of variation for cold carcass weight (P < 0.05) and lean meat% (P < 0.05). Pigs born in litters with more liveborn pigs were at greater risk of death and to be lame prior to slaughter (P < 0.05). Pigs that were cross-fostered once were 11.69 times, and those that were cross-fostered ≥2 times were 7.28, times more likely to die compared with pigs that were not cross-fostered (P < 0.05). Further, pigs that were cross-fostered once were at greater risk of pericarditis and heart condemnations compared with pigs that were not cross-fostered (P < 0.05). Pigs with a birth BW of <0.95 kg were at higher mortality risk throughout the production cycle. There was an increased risk of lameness, pleurisy, pericarditis and heart condemnations (P < 0.05) for pigs with lower weaning weights. Additionally, heavier pigs at weaning also had higher carcass weights (P < 0.05). There was an increased risk of lameness for pigs weaned at a younger age (P < 0.05). Males were 2.27 times less likely to receive a score of zero for tail biting compared with female pigs. Results from this study highlight the complex relationship between management, performance and disease in pigs. They confirm that special attention should be given to lighter weight pigs and pigs born to first parity sows and that cross-fostering should be minimised

A cross-sectional survey on respiratory disease in a cohort of Irish pig farms

Altres ajuts: Department of Agriculture, Food and the Marine PathSurvPig 14/S/832Respiratory disease is one of the most important factors impacting pig production worldwide. There is no available information on the prevalence of key pathogens implicated in Irish pig production. The objective of this study was to describe the prevalence of pleurisy, pneumonia, lung abscesses, pericarditis and liver milk spots in finisher pigs of a cohort of Irish pig farms, and to describe the seroprevalence of: influenza A virus (IAV), porcine reproductive and respiratory syndrome virus (PRRSv), Mycoplasma hyopneumoniae (Mhyo) and Actinobacillus pleuropneumoniae (APP). In brief, 56 farrow-to-finish farms (29% of the Irish breeding herd) were enrolled in the study in 2017. Data on lungs, heart, and liver lesions were assessed for each farm at slaughter. An average of 417 (range 129-1154) plucks per farm were assessed for pleurisy, pneumonia, lung abscesses, pericarditis, and liver milk spots. Blood samples from 32 finisher pigs were collected at slaughter for each farm. The observed prevalence of pleurisy and pneumonia was one of the lowest reported in similar studies in Europe (13 and 11% estimated average within farm, respectively). Pleurisy lesions were mostly moderate and severe. Pneumonia lesions affected a low level of lung surface (5.8%). Prevalence of pericarditis was mid-high (8%) and the prevalence of liver milk spots was high, with an average of 29% of the livers affected. For serology, 78.6% of the farms were positive for IAV, 50% were positive for PRRSv, 71.4% were positive for Mhyo, and 98.2% were positive for APP. Influenza virus was the main pathogen associated with pleurisy (P < 0.001) and Mhyo was the main pathogen associated with pneumonia (P < 0.001) and pericarditis (P = 0.024). Farms affected with pleurisy had moderate to severe lesions. Farms affected with pneumonia had mild lesions, which could be the effect of the generalised use of Mhyo vaccination in piglets. The seroprevalence of IAV, PRRSv, Mhyo and APP in the present study sample is similar to or lower than in other European countries. Further research on the PRRSv and APP strains circulating in Ireland is necessary to support the design of national or regional control plans

Bovine milk somatic cell transcriptomic response to Staphylococcus aureus is dependent on strain genotype

peer-reviewedBackground Mastitis is an economically important disease of dairy cows with Staphylococcus aureus a major cause worldwide. Challenge of Holstein-Friesian cows demonstrated that S. aureus strain MOK124, which belongs to Clonal Complex (CC)151, caused clinical mastitis, while strain MOK023, belonging to CC97, caused mild or subclinical mastitis. The aim of this study was to elucidate the molecular mechanisms of the host immune response utilising a transcriptomic approach. Milk somatic cells were collected from cows infected with either S. aureus MOK023 or MOK124 at 0, 24, 48, 72 and 168 h post-infection (hpi) and analysed for differentially expressed (DE) genes in response to each strain. Results In response to MOK023, 1278, 2278, 1986 and 1750 DE genes were found at 24, 48, 72 and 168 hpi, respectively, while 2293, 1979, 1428 and 1544 DE genes were found in response to MOK124 at those time points. Genes involved in milk production (CSN1, CSN10, CSN1S2, CSN2, a-LACTA and PRLR) were downregulated in response to both strains, with a more pronounced decrease in the MOK124 group. Immune response pathways such as NF-κB and TNF signalling were overrepresented in response to both strains at 24 hpi. These immune pathways continued to be overrepresented in the MOK023 group at 48 and 72 hpi, while the Hippo signalling, extracellular matrix interaction (ECM) and tight junction pathways were overrepresented in the MOK124 group between 48 and 168 hpi. Cellular composition analysis demonstrated that a neutrophil response was predominant in response to MOK124, while M1 macrophages were the main milk cell type post-infection in the MOK023 group. Conclusions A switch from immune response pathways to pathways involved in maintaining the integrity of the epithelial cell layer was observed in the MOK124 group from 48 hpi, which coincided with the occurrence of clinical signs in the infected animals. The higher proportion of M1 macrophages in the MOK023 group and lack of substantial neutrophil recruitment in response to MOK023 may indicate immune evasion by this strain. The results of this study highlight that the somatic cell transcriptomic response to S. aureus is dependent on the genotype of the infecting strain

Clinical presentation and immune characteristics in first-lactation Holstein-Friesian cows following intramammary infection with genotypically distinct Staphylococcus aureus strains

peer-reviewedStaphylococcus aureus is an important cause of bovine mastitis, and intramammary infections caused by this pathogen are often characterized as mild, chronic, or persistent. The strains of Staph. aureus associated with mastitis belong to several distinct bovine-adapted bacterial lineages. Studies of host-pathogen interactions have demonstrated that significant differences exist between Staph. aureus strains and lineages in their ability to internalize and to elicit expression of chemokines and pro-inflammatory mediators in bovine cells in vitro. To determine the effect of bacterial strain on the response to intramammary infection in vivo, 14 disease-free, first-lactation cows were randomly allocated to 2 groups and challenged with Staph. aureus strain MOK023 (belonging to CC97) or MOK124 (belonging to CC151). Clinical signs of infection, as well as somatic cell count (SCC), bacterial load, IL-8 and IL-1β in milk, anti-Staph. aureus IgG in milk and serum, anti-Staph. aureus IgA in milk, and white blood cell populations in milk and blood were monitored for 30 d after the challenge. Cows infected with MOK023 generally developed subclinical mastitis, whereas cows infected with MOK124 generally developed clinical mastitis. Milk yield was reduced to a greater extent in response to infection with MOK124 compared with MOK023 in the first week of the study. Significantly higher SCC, IL-8, and IL-1β in milk as well as higher anti-Staph. aureus IgG and IgA in milk and anti-Staph. aureus IgG in serum were also observed in response to MOK124 compared with the response to MOK023. Higher proportions of neutrophils were observed in milk of animals infected with MOK124 than in animals infected with MOK023. Higher neutrophil concentration in blood was also observed in the MOK124 group compared with the MOK023 group. Overall, the results indicate that the outcome of mastitis mediated by Staph. aureus is strain dependent

Surveillance Data Highlights Feed Form, Biosecurity, and Disease Control as Significant Factors Associated with Salmonella Infection on Farrow-to-Finish Pig Farms

Copyright © 2018 Argüello, Manzanilla, Lynch, Walia, Leonard, Egan, Duffy, Gardiner and Lawlor. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.[EN] Among the zoonotic pathogens affecting pigs, Salmonella stands out due to the high number of human cases linked to pork consumption. In the last two decades many countries have put considerable effort into the control of the infection by surveillance and control strategies on farm. Despite this effort, many herds still have a high Salmonella prevalence and they require guidance to address this problem. The present study, using the serological surveillance data of finishing pigs from the Irish National pig Salmonella Control Programme, aimed to highlight factors associated with increased risk or that might mitigate Salmonella occurrence on farm. A questionnaire with 33 questions regarding herd characteristics, management, feeding, biosecurity, and health was completed for 61 individual herds. After the multivariate analysis by linear regression, nine variables were retained in the final model and linked to herd seroprevalence. Home produced-feed linked to the use of meal showed an eight points reduction in Salmonella prevalence compared to purchased feed (p = 0.042). Different biosecurity measures were associated to lower seroprevalence. Changing of footwear from outside to inside the farm decreased seroprevalence nearly 20 units (p = 0.014) and policies not permitting access to the farmyard to feed trucks (p = 0.048) or avoiding the presence of cats on the farm (p = 0.05) were estimated in 10 units less of seroprevalence. In contrast, the lack of perimeter fence increased the chance to have higher seroprevalence in five units (p = 0.05). Finally, intestinal diseases such as swine dysentery (p = 0.044) and E. coli diarrhea (p = 0.1) were estimated to increase Salmonella prevalence in ~20 and 10 units, respectively, demonstrating the importance of controlling other enteric pathogens in an on-farm Salmonella control programme. These results show the usefulness of surveillance data to improve on-farm control and confirm that Salmonella infection in pigs is multi-factorial and the approach to its control should be multifaceted.SIThis study was funded by the Food Institutional Research Measure (FIRM) administered by the Department of Agriculture Food and the Marine (DAFM) (FIRM/RSF/CoFoRD 2011 Project 11/SF/329).The authors gratefully acknowledge the staff at Longtown Research Farm and the Central Veterinary Research Laboratory (CVRL) Backweston for their expert help in the serological analyses of the study

Influence of the Intestinal Microbiota on Colonization Resistance to Salmonella and the Shedding Pattern of Naturally Exposed Pigs

[EN] Salmonella colonization and infection in production animals such as pigs are a cause for concern from a public health perspective. Variations in susceptibility to natural infection may be influenced by the intestinal microbiota. Using 16S rRNA compositional sequencing, we characterized the fecal microbiome of 15 weaned pigs naturally infected with Salmonella at 18, 33, and 45 days postweaning. Dissimilarities in microbiota composition were analyzed in relation to Salmonella infection status (infected, not infected), serological status, and shedding pattern (nonshedders, single-point shedders, intermittent-persistent shedders). Global microbiota composition was associated with the infection outcome based on serological analysis. Greater richness within the microbiota postweaning was linked to pigs being seronegative at the end of the study at 11 weeks of age. Members of the Clostridia, such as Blautia, Roseburia, and Anaerovibrio, were more abundant and part of the core microbiome in nonshedder pigs. Cellulolytic microbiota (Ruminococcus and Prevotella) were also more abundant in noninfected pigs during the weaning and growing stages. Microbial profiling also revealed that infected pigs had a higher abundance of Lactobacillus and Oscillospira, the latter also being part of the core microbiome of intermittent-persistent shedders. These findings suggest that a lack of microbiome maturation and greater proportions of microorganisms associated with suckling increase susceptibility to infection. In addition, the persistence of Salmonella shedding may be associated with an enrichment of pathobionts such as Anaerobiospirillum. Overall, these results suggest that there may be merit in manipulating certain taxa within the porcine intestinal microbial community to increase disease resistance against Salmonella in pigs. IMPORTANCE Salmonella is a global threat for public health, and pork is one of the main sources of human salmonellosis. However, the complex epidemiology of the infection limits current control strategies aimed at reducing the prevalence of this infection in pigs. The present study analyzes for the first time the impact of the gut microbiota in Salmonella infection in pigs and its shedding pattern in naturally infected growing pigs. Microbiome (16S rRNA amplicon) analysis reveals that maturation of the gut microbiome could be a key consideration with respect to limiting the infection and shedding of Salmonella in pigs. Indeed, seronegative animals had higher richness of the gut microbiota early after weaning, and uninfected pigs had higher abundance of strict anaerobes from the class Clostridia, results which demonstrate that a fast transition from the suckling microbiota to a postweaning microbiota could be crucial with respect to protecting the animalsSIThis study was funded by the Food Institutional Research Measure (FIRM) administered by the Department of Agriculture Food and the Marine (DAFM). H.A. is a postdoctoral researcher supported by the Juan de la Cierva Postdoctoral Trainee Program of the Spanish Ministry of Economy and Competitiveness (IJCI-2016-30795). H.A. was funded by the PiGutNet COST action (FA1401) for a Short-Term Scientific Mission at INRA’s GABI laboratory (Jouy-en-Josas, France). We gratefully acknowledge the Central Veterinary Research Laboratory (CVRL) Backweston for their expert help with the serological analyses. H.A. participated in the study design, sample collection and processing, data analysis, and manuscript writing. F.C.L. participated in study design and manuscript correction. J.E. participated in data analysis and manuscript revision. P.D.C. and F.C. participated in microbiome sequencing and manuscript revision. O.O. performed part of the data analysis and manuscript revision. H.L. and K.W. participated in sample collection and processing. G.D. and P.G.L. participated in the study design and manuscript correction. G.E.G. participated in the study design, data analysis, and manuscript writin

Quantification, description and international comparison of antimicrobial use on Irish pig farms

Peer-reviewedAbstract Background There is concern that the use of antimicrobials in livestock production has a role in the emergence and dissemination of antimicrobial resistance in animals and humans. Consequently, there are increasing efforts to reduce antimicrobial use (AMU) in agriculture. As the largest consumer of veterinary antimicrobials in several countries, the pig sector is a particular focus of these efforts. Data on AMU in pig production in Ireland are lacking. This study aimed to quantify AMU on Irish pig farms, to identify the major patterns of use employed and to compare the results obtained to those from other published reports and studies. Results Antimicrobial use data for 2016 was collected from 67 Irish pig farms which represented c. 35% of national production. The combined sample population consumed 14.5 t of antimicrobial by weight of active ingredient suggesting that the pig sector accounted for approximately 40% of veterinary AMU in Ireland in 2016. At farm level, median AMU measured in milligram per population correction unit (mg/PCU) was 93.9 (range: 1.0–1196.0). When measured in terms of treatment incidence (TI200), median AMU was 15.4 (range: 0.2–169.2). Oral treatments accounted for 97.5% of all AMU by weight of active ingredient and were primarily administered via medicated feed to pigs in the post weaning stages of production. AMU in Irish pig production in 2016 was higher than results obtained from the national reports of Sweden, Denmark, the Netherlands and France but lower than the United Kingdom. Conclusions Pig production in Ireland is an important consumer of veterinary antimicrobials. The quantities and patterns of AMU on Irish pig farms are comparable to pig production in other European countries but higher than some countries with more advanced AMU reduction strategies. This AMU is characterised by a high proportion of prophylactic use and is primarily administered to pigs post weaning via medicated feed. Further studies to better understand the reasons for AMU on Irish pig farms and strategies to improve health among weaner pigs will be of benefit in the effort to reduce AMU