A 10-day vacancy period after cleaning and disinfection has no effect on the bacterial load in pig nursery units

Escherichia coli resistant to the highest priority critically important fluoroquinolone or 3rd and 4th generation cephalosporin antibiotics persist in pigsties

Antimicrobial resistance threatens human and animal health, with antimicrobial usage being a key driver of selection, transmission, and spread of resistant bacteria. Livestock represents a potential reservoir for human transmission, leading authorities to restrict veterinary usage of fluoroquinolones and certain cephalosporins. However, growing evidence indicates that the corresponding resistance determinants can be retained even in the drugs' absence. To obtain data on the magnitude and dynamics of this phenomenon in pig farming, we quantitatively and qualitatively assessed fluoroquinolone- and cephalosporin-resistant Escherichia coli in Thuringian pigsties practicing a closed management system to minimize the impact of externally introduced strains. Pooled fecal samples from consecutive fattening runs at one conventional and two organic farms and from 25 piglet groups from another conventional farm were collected over 16 months and screened for E. coli on plates containing enrofloxacin, ceftiofur, or cefquinome. Resistant bacteria were isolated on all farms; their counts varied strongly but were generally higher in piglets and declined with increasing animal age. Phylogenetic comparison of 393 isolates was performed via multiple-locus variable number tandem repeat analysis (MLVA) to follow strain dynamics and persistence. The isolates displayed large phylogenetic heterogeneity, featuring 52 different MLVA patterns. Still, conserved MLVA patterns indicated long-term persistence of specific strains in each farm's environment. This suggests that resistant strains appear well-adapted to the particular farm and its management practices, implying that, beyond restricting usage, further measures, including, e.g., consideration of the type of resistance as well as its persistence and transmission dynamics, will be indispensable to reduce the antimicrobial resistance load in pork production.IMPORTANCEAntimicrobial resistance (AMR) represents a global threat to human and animal health, with animals considered a reservoir for transmission of AMR to humans. Because antimicrobial usage is a driver for resistance, one approach to decrease the AMR burden is to reduce its usage. However, this can, but does not necessarily, lead to lower AMR prevalence. German and EU legislation restrict the use of fluoroquinolones and certain cephalosporins, substance classes designated as highest priority critically important antimicrobials for human medicine, in animal husbandry. Longitudinal sampling of organic and conventional farms in Thuringia for resistance to these antibiotic classes revealed that certain resistant Escherichia coli strains can persist in the farm environment over extended time periods. These strains displayed farm specificity, indicating adaptation to the particular farm and its management practices, so that their elimination might be difficult, requiring either procedures acting generally against Enterobacterales or targeted action against the specific strains.

Intervention strategies for methicillin-resistant Staphylococcus aureus control in pig farming: a comprehensive review

Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious public health threat due to its zoonotic potential and resistance to several antibiotic classes. Pig farming is recognized as a key reservoir for livestock-associated MRSA, necessitating effective intervention strategies to mitigate its prevalence. The objective of this narrative review was to summarize the current knowledge on the approaches to control MRSA on pig farms. The review process involved a comprehensive search across three electronic databases focusing on studies from 2000 to 2024 in both English and German.The review covers intervention measures including reduced antimicrobial use, cleaning and disinfection, air filtration, and bacteriophage application. Key findings indicate that, while interventions such as cleaning and disinfection and air filtration, can effectively reduce environmental MRSA loads, these measures are often insufficient for long-term control due to frequent recontamination, especially restocking with MRSA-positive animals. Eradication was shown to be effective in low-prevalence regions such as Norway, however, logistical and ethical challenges limit its feasibility in areas with high MRSA prevalence. Additional interventions, such as reduced antimicrobial use and sow washing, provided inconsistent results.Overall, the findings highlight the need for a multifaceted approach, combining several interventions tailored to regional MRSA prevalence, farm management practices, and available resources. Such an integrated strategy is essential for sustainable MRSA control in pig farming, thereby supporting the global One Health initiative aimed at mitigating antimicrobial resistance.

Insights into the genomic and phenotypic characteristics of Bacillus spp. strains isolated from biofilms in broiler farms

The characterization of surface microbiota living in biofilms within livestock buildings has been relatively unexplored, despite its potential impact on animal health. To enhance our understanding of these microbial communities, we characterized 11 spore-forming strains isolated from two commercial broiler chicken farms. Sequencing of the strains revealed them to belong to three species Bacillus velezensis, Bacillus subtilis, and Bacillus licheniformis. Genomic analysis revealed the presence of antimicrobial resistance genes and genes associated with antimicrobial secretion specific to each species. We conducted a comprehensive characterization of the biofilm formed by these strains under various conditions, and we revealed significant structural heterogeneity across the different strains. A macro-colony interaction model was employed to assess the compatibility of these strains to coexist in mixed biofilms. We identified highly competitive B. velezensis strains, which cannot coexist with other Bacillus spp. Using confocal laser scanning microscopy along with a specific dye for extracellular DNA, we uncovered the importance of extracellular DNA for the formation of B. licheniformis biofilms. Altogether, the results highlight the heterogeneity in both genome and biofilm structure among Bacillus spp. isolated from biofilms present within livestock buildings.IMPORTANCELittle is known about the microbial communities that develop on farms in direct contact with animals. Nonpathogenic strains of Bacillus velezensis, Bacillus subtilis, and Bacillus licheniformis were found in biofilm samples collected from surfaces in contact with animals. Significant genetic and phenotypic diversity was described among these Bacillus strains. The strains do not possess mobile antibiotic resistance genes in their genomes and have a strong capacity to form structured biofilms. Among these species, B. velezensis was noted for its high competitiveness compared with the other Bacillus spp. Additionally, the importance of extracellular DNA in the formation of B. licheniformis biofilms was observed. These findings provide insights for the management of these surface microbiota that can influence animal health, such as the use of competitive strains to minimize the establishment of undesirable bacteria or enzymes capable of specifically deconstructing biofilms.

Multidrug-Resistant Staphylococcus aureus Colonizing Pigs and Farm Workers in Rio de Janeiro State, Brazil: Potential Interspecies Transmission of Livestock-Associated MRSA (LA-MRSA) ST398

Multidrug-resistant (MDR) Staphylococcus aureus has been increasingly isolated from pigs and people in close contact with them, especially livestock-associated methicillin-resistant S. aureus (LA-MRSA). In this cross-sectional study, we investigated S. aureus colonization in pigs and farm workers, their resistance profile, and genetic background to estimate interspecies transmission potential within farms from Rio de Janeiro state, Brazil, between 2014 and 2019. We collected nasal swabs from 230 pigs and 27 workers from 16 and 10 farms, respectively. Five MDR strains were subjected to whole genome sequencing. Fourteen (6.1%) pigs and seven (25.9%) humans were colonized with S. aureus, mostly (64-71%) MDR strains. Resistance to clindamycin, erythromycin, penicillin, and tetracycline was the most common among the pig and human strains investigated. MDR strains shared several resistance genes [blaZ, dfrG, fexA, lsa(E), and tet(M)]. Pig and human strains recovered from the same farm shared the same genetic background and antimicrobial resistance profile. LA-MRSA ST398-SCCmecV-t011 was isolated from pigs in two farms and from a farm worker in one of them, suggesting interspecies transmission. The association between pig management practices and MDR S. aureus colonization might be investigated in additional studies.

Effect of implementing an effective farrowing accommodation hygiene routine on clinical cases of disease, medication usage, and growth in suckling and weaned pigs

The few studies that have evaluated hygiene routines in farrowing accommodation to date have focused on pathogen elimination from pens, with little attention paid to pig growth and no information provided on pig health or medication usage. This study aimed to determine if implementation of an optimized farrowing accommodation hygiene routine could improve pig health and growth and reduce medication usage pre- and post-weaning (PW). Forty seven sows were blocked on parity, previous litter size and body weight and assigned to two treatments: T1) Basic hygiene: cold water washing only with minimal drying time; T2) Optimized hygiene: use of detergent and a chlorocresol-based disinfectant with a 6-d drying time. Total bacterial counts (TBC), Enterobacteriaceae counts and adenosine triphosphate (ATP) swabs were obtained from different areas within the farrowing pens. Pig growth and medication usage were monitored from birth to slaughter and carcass data were obtained at slaughter. On entry of sows to the farrowing pens, TBC and Enterobacteriaceae counts and ATP concentrations were lower on pen surfaces subjected to the optimized compared to the basic hygiene routine (P < 0.05). Pre-weaning diarrhea prevalence was lower in pigs born into optimal compared to basic hygiene pens (0 vs. 22%; P < 0.001). The number of clinical cases of disease and injections administered to piglets per litter was 75% and 79% less for the optimized compared to the basic hygiene routine, respectively (P < 0.001). This led to reductions of 77% (P < 0.001) and 75% (P < 0.01), respectively in the volume of antibiotics and anti-inflammatories administered per litter in the optimized hygiene group. Pigs from the optimized hygiene treatment were also heavier at weaning (P < 0.01) and their average daily gain (ADG) was higher from day 21 to weaning and days 22 to 49 PW (P < 0.05). However, these growth improvements did not carry through to the finisher period. In conclusion, implementation of an optimized hygiene routine reduced the bacterial load in farrowing pens, leading to a reduction in diarrhea and clinical cases of disease and therefore, medication usage, in suckling pigs. Pig growth was also improved during the suckling and early PW periods. Based on the results, an easily implementable farrowing room hygiene protocol with demonstrable benefits for pig health, growth, and welfare can be provided to farmers.

How Does Epidemic Prevention Training for Pig Breeding Affect Cleaning and Disinfection Procedures Adoption? Evidence from Chinese Pig Farms

African Swine Fever (ASF) is a highly infectious disease, severely affecting domestic pigs and wild boar. It has significantly contributed to economic losses within the pig farming industry. As a critical component of biosecurity measures, the selection of cleaning and disinfection (C&D) procedures is a dynamic and long-term decision that demands a deeper knowledge base among pig farmers. This study uses a binary logit model to explore the effect of epidemic prevention training on the adoption of C&D procedures among pig farmers with irregular and regular C&D procedures based on micro-survey data obtained from 333 pig farmers from Sichuan. The endogeneity issue was handled using propensity score matching, resulting in solid conclusions. In addition, the critical mediating impact of biosecurity cognition was investigated using a bootstrap analysis. The empirical study demonstrated that epidemic prevention training encourages pig farmers to adopt C&D procedures, with biosecurity cognition significantly mediating. Furthermore, epidemic prevention training was more likely to promote the adoption of C&D procedures among pig farmers with shorter breeding experiences and those having breeding insurance. Our study emphasized the importance of implementing epidemic prevention training to improving pig farmers' biosecurity cognition and promoting the adoption of C&D procedures. The results included suggested references for preventing ASF and the next epidemic of animal diseases.

Biosecurity and water, sanitation, and hygiene (WASH) interventions in animal agricultural settings for reducing infection burden, antibiotic use, and antibiotic resistance: a One Health systematic review

Prevention and control of infections across the One Health spectrum is essential for improving antibiotic use and addressing the emergence and spread of antibiotic resistance. Evidence for how best to manage these risks in agricultural communities-45% of households globally-has not been systematically assembled. This systematic review identifies and summarises evidence from on-farm biosecurity and water, sanitation, and hygiene (WASH) interventions with the potential to directly or indirectly reduce infections and antibiotic resistance in animal agricultural settings. We searched 17 scientific databases (including Web of Science, PubMed, and regional databases) and grey literature from database inception to Dec 31, 2019 for articles that assessed biosecurity or WASH interventions measuring our outcomes of interest; namely, infection burden, microbial loads, antibiotic use, and antibiotic resistance in animals, humans, or the environment. Risk of bias was assessed with the Systematic Review Centre for Laboratory Animal Experimentation tool, Risk of Bias in Non-Randomized Studies of Interventions, and the Appraisal tool for Cross-Sectional Studies, although no studies were excluded as a result. Due to the heterogeneity of interventions found, we conducted a narrative synthesis. The protocol was pre-registered with PROSPERO (CRD42020162345). Of the 20 672 publications screened, 104 were included in this systematic review. 64 studies were conducted in high-income countries, 24 studies in upper-middle-income countries, 13 studies in lower-middle-income countries, two in low-income countries, and one included both upper-middle-income countries and lower-middle-income countries. 48 interventions focused on livestock (mainly pigs), 43 poultry (mainly chickens), one on livestock and poultry, and 12 on aquaculture farms. 68 of 104 interventions took place on intensive farms, 22 in experimental settings, and ten in smallholder or subsistence farms. Positive outcomes were reported for ten of 23 water studies, 17 of 35 hygiene studies, 15 of 24 sanitation studies, all three air-quality studies, and 11 of 17 other biosecurity-related interventions. In total, 18 of 26 studies reported reduced infection or diseases, 37 of 71 studies reported reduced microbial loads, four of five studies reported reduced antibiotic use, and seven of 20 studies reported reduced antibiotic resistance. Overall, risk of bias was high in 28 of 57 studies with positive interventions and 17 of 30 studies with negative or neutral interventions. Farm-management interventions successfully reduced antibiotic use by up to 57%. Manure-oriented interventions reduced antibiotic resistance genes or antibiotic-resistant bacteria in animal waste by up to 99%. This systematic review highlights the challenges of preventing and controlling infections and antimicrobial resistance, even in well resourced agricultural settings. Most of the evidence emerges from studies that focus on the farm itself, rather than targeting agricultural communities or the broader social, economic, and policy environment that could affect their outcomes. WASH and biosecurity interventions could complement each other when addressing antimicrobial resistance in the human, animal, and environmental interface.

Biosecurity and Hygiene Procedures in Pig Farms: Effects of a Tailor-Made Approach as Monitored by Environmental Samples

In livestock, the importance of hygiene management is gaining importance within the context of biosecurity. The aim of this study was to monitor the implementation of biosecurity and hygiene procedures in 20 swine herds over a 12-month period, as driven by tailor-made plans, including training on-farm. The measure of adenosine triphosphate (ATP) environmental contents was used as an output biomarker. The presence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) and extended-spectrum β-lactamase producing Escherichia coli (ESBL-E. coli) was also investigated as sentinels of antibiotic resistance. A significant biosecurity improvement (p = 0.006) and a reduction in the ATP content in the sanitised environment (p = 0.039) were observed. A cluster including 6/20 farms greatly improved both biosecurity and ATP contents, while the remaining 14/20 farms ameliorated them only slightly. Even if the ESBL-E. coli prevalence (30.0%) after the hygiene procedures significantly decreased, the prevalence of LA-MRSA (22.5%) was unaffected. Despite the promising results supporting the adoption of tailor-made biosecurity plans and the measure of environmental ATP as an output biomarker, the high LA-MRSA prevalence still detected at the end of the study underlines the importance of improving even more biosecurity and farm hygiene in a one-health approach aimed to preserve also the pig workers health.

Are There Effective Intervention Measures in Broiler Production against the ESBL/AmpC Producer Escherichia coli?

Extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase (AmpC) producing Enterobacteriaceae occur frequently in livestock animals and the subsequent stages of the meat production chain and are therefore considered a risk for human health. Strict biosecurity measures and optimal farm management should reduce or even prevent poultry flock colonization at farm level. This review summarizes and evaluates published information on the effectiveness of specific intervention measures and farm management factors aiming to reduce the occurrence and spread of ESBL/AmpC producing or commensal or pathogenic E. coli in broiler chicken farms. In this systematic literature review, a total of 643 publications were analyzed, and 14 studies with significant outcome about the effectiveness of specific measures against E. coli and ESBL/AmpC producing E. coli in broiler chicken farms were found. Different feed additives seem to have an impact on the occurrence of those microorganisms. The measures ‘cleaning and disinfection’ and ‘competitive exclusion’ showed strong effects in prevention in some studies. In summary, some intervention measures showed potential to protect against or eliminate ESBL/AmpC-producing, commensal or pathogenic E. coli at farm level. Due to the high variability in the outcome of the studies, more specific, detailed investigations are needed to assess the potential of the individual intervention measures.

Oocyst shedding patterns of Eimeria species and their association with management and performance at ten rose veal starter farms in the Netherlands

Coccidiosis at rose veal starter farms is often diagnosed however, this was the first study performed considering this topic on this type of rearing unit. The objective of this study was to identify Eimeria species faecal shedding patterns at ten Dutch rose veal starter farms during rearing. Further objectives were to investigate associations with (gut) health, production and management decisions. Faecal samples from twelve randomly selected calves per farm were collected weekly during 9 consecutive weeks. Thereafter samples were pooled in a predetermined composition of six. These calves were clinically evaluated every sample visit and weighed at the first and last visit. Laboratory tests included a flotation test of the samples. If this yielded Eimeria oocysts, both oocysts per gram feces (OPG) and species differentiation were established using a modified McMaster method. Management parameters and technical herd results were identified after finalizing the study period using a questionnaire. Studied patterns in oocyst shedding included the pool's cumulated OPG, maximum OPG level and the number of sample days (SD) that OPG exceeded a confirmed level. Statistical analysis included univariate and multivariate analysis. Associated (p < 0.10) OPG patterns considering rumen fill, faecal consistency and average daily weight gain (ADG) were tested using a model with herd included as random effect. RESULTS: on all ten farms E. alabamensis, E.bovis and E. zuernii besides non-pathogenic species were identified, often as mixed infections. Peak OPG occurred predominately at SD 21 and 28 (E. alabamensis and E. bovis), and at SD 42 (E. zuernii). In 16 pools, OPG levels ≥500 for E. bovis or E. zuernii, were found. Significant correlation (p < 0.0001) showed between the log₁₀ OPG of pathogenic Eimeria and of all Eimeria species. Multivariate analysis showed significant correlation between cumulative faecal consistency scores and cumulative log₁₀ OPG of pathogenic Eimeria species (β = 0.16; p = 0.008). Pools exceeding 750 OPG for E. bovis showed 93 g lower ADG and pools experiencing ≥2 SD with >1000 OPG for E. alabamensis 141 g lower ADG. From the questionnaire we identified lower cumulated OPG of all Eimeria species except for E. bovis at farms where the units were cleaned before arrival of the calves. CONCLUSION: As a rule, on Dutch rose veal starter farms, mixed Eimeria infections occur, but shedding patterns differ between farms. Clinical and growth performance is related to OPG patterns found. Cleaning units before arrival of calves lowers oocyst shedding during the rearing period.

Evaluation of adenosine triphosphate testing for on-farm cleanliness monitoring compared to microbiological testing in an empty pig farrowing unit

Careful cleaning and disinfection of pigpens is essential to prevent disease spread and avoid the resultant economic losses. Hygiene in pigpens is generally evaluated by visual monitoring supplemented with bacteriological monitoring, which includes counting the total aerobic bacteria (TAB) and/or fecal indicator bacteria (FIB). However, these methods present drawbacks such as time and labor requirements. As adenosine triphosphate (ATP) is ubiquitous in all living organisms including microorganisms, this study aimed to directly compare the results of microbial assessment and ATP quantification, and to suggest possible detailed application methods of the ATP test for hygiene evaluation in pigpens of a farrowing unit. Before and after standard cleaning procedures, samples were collected from the floor corner, floor center, and feeding trough of four pigpens at different time points. No FIB were detected and both the TAB and ATP levels were significantly decreased in the floor center area after cleaning. FIB were continuously detected after cleaning and disinfection of the floor corners, and there was no significant ATP level reduction. The feeding trough did not show any significant difference in these values before and after cleaning, indicating insufficient cleaning of this area. The levels of TAB and ATP after cleaning were significantly correlated and the average ATP value was significantly lower in the absence of FIB than in their presence. In the absence of standard references, a more thorough hygiene management could be achieved evenly by supplementing cleaning or disinfection based on the lowest ATP results obtained at the cleanest test site, which in the present study was the floor center. Overall, these results indicate that the on-farm ATP test can be used to determine the cleanliness status, in addition to visual inspection, as an alternative to laboratory culture-based testing for the presence of microorganisms.

Postweaning mortality in commercial swine production. I: review of non-infectious contributing factors

Postweaning mortality is a complex causal matrix involving animal, environment, and infectious etiologic factors. Despite advances in swine productivity such as total pigs born, growth rate, feed intake, and efficiency, there have been modest to no improvements in postweaning mortality rates over the last several years. Industry averages for postweaning mortality range from four to eight percent for each the nursery, grow-finish, or wean-finish stages. Retrospective mortality causal analyses of individual databases have been performed. However, little information derived from meta-analysis, systematic review, or comprehensive literature reviews are available. In order to develop and evaluate strategies to comprehensively manage and reduce postweaning mortality, addressing the complexity and range of impact that factors have on mortality is necessary to identify and prioritize such contributing factors. Our objective is to describe the current state of knowledge regarding non-infectious causes of postweaning mortality, focusing on estimates of frequency and magnitude of effect where available. Postweaning mortality can be generalized into non-infectious and infectious causes, with non-infectious factors further classified into anatomic abnormalities, toxicity, animal factors, facility factors, nutritional inadequacies, season, and management factors. Important non-infectious factors that have been identified through review of literature include birth weight, pre-weaning management, weaning age and weight, and season. Additionally, reasons for mortality with a low incidence but a high magnitude include abdominal organ torsion/volvulus, sodium ion or ionophore toxicosis, or dietary imbalance due to feed formulation or manufacture error. Many interactive effects are present between and among infectious and non-infectious factors, but an important trend is the impact that non-infectious factors have on the incidence, severity, and resolution of infectious disease. Strategies to reduce postweaning mortality must consider the dynamic, complex state that forms the causal web. Control of postweaning mortality through understanding of the complexity, evaluation of mortality reduction strategies through rigorous scientific evaluation, and implementation remains an area of opportunity for continued growth and development in the global swine industry.

Individual training for farmers based on results from protein and ATP rapid tests and microbiological conventional cultural methods improves hygiene in pig fattening pens

Optimal hygiene management is an essential part of maintaining a high standard of health in conventional pig production systems and for the successful interruption of infection chains. Currently, efficiency assessments on cleaning and disinfection are only performed by visual inspection or are neglected completely. The aim of this study was to evaluate the available methods for on farm monitoring of hygiene, identify critical points in pig pens and use the data obtained for training purposes. In addition to visual inspection by assessing the cleanliness, microbiological swab samples, i.e., aerobic total viable count (TVC), total coliform count, methicillin-resistant Staphylococcus aureus (MRSA), and extended-spectrum β-lactamases-producing bacteria (ESBL), swab samples for ATP as well as protein residues and agar contact plates combined with 3 different culture media, were applied and ranked according to their suitability for livestock farming. Samples were collected on at least 15 critical points from one representative pen on 6 pig fattening farms with various hygiene management practices after cleaning and disinfection. After the first sampling, farmers were trained with their individual results, and sampling was repeated 6 mo after training. Nipple drinkers, feeding tubes (external and inner surface), and troughs (external and inner surface) showed the greatest bacterial loads (TVC: 4.5-6.7 log10 cfu cm-2) and values for ATP and protein residues; therefore, these surfaces could be identified as the most important critical points. Spearman rank correlations (P < 0.01) were found between the different assessment methods, especially for the TVC and ATP (r = 0.82, P < 0.001). For rapid assessment on farms, ATP tests represented an accurate and cost-efficient alternative to microbiological techniques. Training improved cleaning performance as indicated by a lower rating for visual inspection, TVC, ATP, MRSA, and ESBL in the second assessment. The monitoring of cleaning efficiency in pig pens followed by training of the staff constitutes a valuable strategy to limit the spread of infectious diseases and antibiotic-resistant bacteria. Special attention should be paid to the sufficient hygiene of drinkers and feeders.

Biosecurity practices in Belgian veal calf farming: Level of implementation, attitudes, strengths, weaknesses and constraints

The shift from cure toward prevention in veterinary medicine involves the implementation of biosecurity. In cattle farming, the application of biosecurity measures has been described to a limited degree, yet no data on biosecurity on veal farms is available. A high degree of commingling of veal calves from multiple farms causes frequent disease outbreaks, and thereby high antimicrobial usage and increased risk of antimicrobial resistance. Therefore, this study aimed to describe the current implementation of biosecurity on veal farms in Belgium. To this extent, a list of the most important calf diseases (n = 34) was created, and risk factors and related biosecurity measures for these diseases were determined and included in a questionnaire. Herd visits and face-to-face interviews were conducted on 20 randomly selected veal farms, comprising 8.3% of the target population. A categorical principal component and clustering analysis were performed to determine the influence of the veal companies on the farms' biosecurity level. Awareness of biosecurity was very low among the farmers. All farms used an "all-in, all-out" production system with calves originating from multiple farms without quarantine. On average, farms were filled in 11.4 days (range 2-52). The degree of commingling for these farms was 1.24, meaning that, on average, 124 calves originated from 100 farms. Veterinarians wore farm-specific boots on eight farms (40%) and farm-specific clothes on six farms (30%), while technical advisors wore farm-specific boots on six farms (30%) and farm-specific clothes on four farms (20%). Disinfection footbaths were only used in five farms (25%) despite being present in all farms in the sample. Concerning internal biosecurity, none of the farmers isolated sick animals; only one farmer (5%) had a physically separated hospital pen, and only 11 farmers (55%) both cleaned and disinfected the stables after each production cycle. In most farms, animals were of comparable age. Healthy calves generally remained in the same compartment during the entire production cycle, limiting the risks associated with the movement of animals. No influence of the integrations on the biosecurity level could be determined. It can be concluded that a few biosecurity measures, such as "'all-in, all-out" and compartmentation, are implemented relatively well, while other measures, such as good cleaning and disinfection and proper entrance measures for visitors and personnel can easily be improved. The improvement of measures regarding the introduction of animals of different origins will require more fundamental changes in the veal industry.

Antimicrobial policies in animals and human health

This invited commentary aims to highlight 3 recommendations to rationalize antimicrobial consumption in livestock, in order to minimize the spread of resistant bacteria and simultaneously safeguarding animal and public health.