The effect of Lameness before and during the breeding season on fertility in 10 pasture-based Irish dairy herds

Background

The effects of lameness on fertility have been documented frequently but few data are available from seasonally breeding, pasture-based herds (such as those used in Ireland) where cows are housed during the winter months but managed at pasture for the remainder of the year. This study determined the prevalence of lameness in a group of 786 cows in 10 pasture-based Irish dairy herds before, during and after the breeding season and assessed the relationship between lameness and the reproductive performance in these herds through serial locomotion scoring during the grazing period.

Results

Lameness prevalences of 11.6 % before, 14.6 % during and 11.6 % after the breeding season were found and these compared favourably to results from housed cattle and are similar to other studies carried out in grazing herds. A Cox proportional hazards model with locomotion score as time varying covariate was used. After controlling for the effect of farm, month of calving, body condition score at calving, body condition score loss after calving and economic breeding index, cows identified as lame during the study were less likely to become pregnant. Cows lame before the earliest serve date but no longer lame during the breeding season, cows becoming lame after the earliest serve date and cows identified lame both before and after this date were respectively 12 %, 35 % and 38 % less likely to become pregnant compared to cows never observed lame during the study. However, these findings were only significant for cows becoming lame after the earliest serve date and cows lame both before and after the start of breeding.

Conclusions

This study found that the reproductive efficiency was significantly (p < 0.05) lower in cows becoming lame during the breeding season and cows lame before and during the breeding season compared to non-lame cows. Cows no longer lame during the breeding season had a lower Submission Rate to first serve within 3 weeks of earliest serve date. However, the Pregnancy Rate was not significantly (p > 0.05) lower in these animals compared to cows never diagnosed as lame. In addition to lameness status, nutritional status and genetics were found to influence the reproductive performance in pasture-based Irish dairy herds.     

Effect of organic acids in drinking water during the last 2 weeks prior to slaughter on Salmonella shedding by slaughter pigs and contamination of carcasses

In this study, we investigated the effect of adding organic acids to the drinking water of finishing pigs 2 weeks prior to slaughter on the shedding and prevalence rate of Salmonella at slaughter. Approximately 600 animals from four Belgian pig herds infected with Salmonella were included. At two herds, the study was conducted twice. Before the start of the study, overshoes were taken at the different herds. Two weeks prior to the expected slaughter date, the pigs were randomly divided into two groups (treatment and control group) each containing on average 50 animals within each herd. The treatment group received from this day onwards acidified drinking water (pH = 3.6-4.0), the control group received non-treated water (pH = 7.8-8.5). All other housing, feeding and management factors were identical in both groups. At the slaughterhouse, 10 pigs of each group (20 pigs for each group of study group 6) were randomly selected and sampled (blood, contents of ileum and rectum, mesenteric lymph nodes and carcass swabs). All samples were immediately transported to the laboratory and submitted to Salmonella isolation. Salmonella was isolated out of 11.9% (66/554) of the samples taken at the slaughterhouse, with the highest frequency found in the content of the ileum (18.7%), followed by 17.8% in the lymph nodes, 7.2% in the content of the rectum and 3.6% in the carcass swabs. The results did not reveal a significant difference between the treatment and control groups for the different slaughterhouse samples. The study documented that the investigated control strategy namely, the strategic application of organic acids during the last 2 weeks prior to slaughter was insufficient to decrease Salmonella shedding and contamination shortly before and during slaughter.     

Effects of Acclimate™ on the frequency and duration of aggressive sequence and growth performance in co-mingled, weaned pigs

Co-mingling weaned pigs often results in aggressive behavior which can result in injury and reduced performance. This experiment examined the effect of Acclimate™, a product reported to reduce equine aggression, on weaned pig aggression and growth performance. Weanling pigs (n=214, avg. wt.=5.93 kg) were blocked by weight, sex and litter (n=25) and randomly assigned to either Acclimate™ treatment or a control group. Acclimate™ treated pigs were marked on the nose, face and neck. Pigs were individually identified and videotaped to determine frequency of aggressive sequence (FAS) and duration of aggression (DOA) on an individual pig basis. Pig weights and feed consumption were used to determine feed intake, total weight gain (TWG), average daily gain (ADG) and feed to gain ratio (F/G). Differences between litter, sex and treatment for FAS, DOA, F/G and ADG were tested using GLM, SAS. Neither Acclimate™ treatment or sex had a significant effect on FAS, TWG or F/G. However, there was a trend towards reduced duration and intensity of aggression in Acclimate™ treated pigs (p=0.1). There was a significant effect of litter (p<0.01) and TWG (p<0.001) on FAS at both 1 and 3 weeks. Acclimate™ treatment of weaned pigs does not decrease FAS, but may decrease the intensity and duration of aggression without negatively effecting growth.     

Opinions of Spanish pig producers on the role,the level and the risk to public health of antimicrobial use in pigs

Antimicrobial use is a major driver of antimicrobial resistance and prescribers (physicians and veterinarians) and end users (patients, food producers and pet owners) are the cornerstones of this scenario. Intensive pig farming is a livestock activity that has a high antimicrobial use. This study is based on the opinions of pig producers.     

A case–case study comparing the individual risk factors and symptomatology of Salmonella Heidelberg and Salmonella Typhimurium in Ontario in 2015, following implementation of the Ontario Investigation Tools

Salmonella Heidelberg and Salmonella Typhimurium are among the most common serotypes responsible for human salmonellosis in Ontario. Introduction of the Ontario Investigation Tools (OIT) in 2014 allowed for standardized case investigation and reporting. This study compared the risk factors and symptomatology for sporadic S. Heidelberg and S. Typhimurium cases reported in Ontario in 2015, following implementation of the OIT. Multilevel logistic regression models were applied to assess associations between serotype and individual‐level demographic characteristics, exposures and symptoms for sporadic confirmed cases of S. Heidelberg and S. Typhimurium in Ontario in 2015. There were 476 sporadic cases of S. Typhimurium (n = 278) and S. Heidelberg (n = 198) reported in Ontario in 2015. There were significant associations between the odds of the isolate from a case being one of these serotypes, and travel, consumption of sprouts (any type), contact with reptiles and development of malaise, fever or bloody diarrhoea. The S. Typhimurium and S. Heidelberg cases differed in both symptom presentation and risk factors for illness. Case–case comparisons of Salmonella serotypes have some advantages over case–control studies in that these are less susceptible to selection and recall bias while allowing for rapid comparison of cases to identify potential high‐risk exposures that are unique to one of the serotypes when compared to the other. Comparing cases of two different Salmonella serotypes can help to highlight risk factors that may be uniquely associated with one serotype, or more strongly associated with one serotype compared to another. This information may be useful for understanding relative source attribution between common serotypes of Salmonella.     

Investigation of the Concurrent Emergence of Salmonella enteritidis in Humans and Poultry in British Columbia,Canada, 2008–2010

An increase in the rate of human infections with Salmonella enteritidis (SE) occurred between 2007 and 2010 in British Columbia (BC). During the same time period, an increase in SE from poultry‐sourced isolates and increased clinical severity in poultry were also observed in BC. This article describes a multi‐sectoral collaboration during a 3‐year investigation, and the actions taken by public health and animal health professionals. Human cases were interviewed, clusters were investigated, and a case–control study was conducted. Environmental investigations were conducted in food service establishments (FSE). Suspect foods were tested. Laboratory data from poultry‐sourced isolates were analysed. Five hundred and eighty‐four human cases of SE with the same pulsed‐field gel electrophoresis pattern were identified between May 2008 and August 2010. Seventy‐three percentage of cases reported consumption of eggs. The odds of egg consumption were 2.4 times higher for cases than controls. Implicated FSE were found to use ungraded eggs, which had been distributed illegally. Investigation suggested that there were multiple suppliers of these eggs. Collaboration between public health and animal health professionals led to data sharing, improved understanding of SE, engagement with the poultry industry and public communication. Multi‐disciplinary, multi‐sectoral and multi‐pronged investigations are recommended to identify the likely source of illness in large, protracted foodborne outbreaks caused by commonly consumed foods.     

Non‐Typhoidal Salmonella Colonization in Chickens and Humans in the Mekong Delta of Vietnam

Salmonellosis is a public health concern in both the developed and developing countries. Although the majority of human non‐typhoidal Salmonella enterica (NTS) cases are the result of foodborne infections or person‐to‐person transmission, NTS infections may also be acquired by environmental and occupational exposure to animals. While a considerable number of studies have investigated the presence of NTS in farm animals and meat/carcasses, very few studies have investigated the risk of NTS colonization in humans as a result of direct animal exposure. We investigated asymptomatic NTS colonization in 204 backyard chicken farms, 204 farmers and 306 matched individuals not exposed to chicken farming, in southern Vietnam. Pooled chicken faeces, collected using boot or handheld swabs on backyard chicken farms, and rectal swabs from human participants were tested. NTS colonization prevalence was 45.6%, 4.4% and 2.6% for chicken farms, farmers and unexposed individuals, respectively. Our study observed a higher prevalence of NTS colonization among chicken farmers (4.4%) compared with age‐, sex‐ and location‐ matched rural and urban individuals not exposed to chickens (2.9% and 2.0%). A total of 164 chicken NTS strains and 17 human NTS strains were isolated, and 28 serovars were identified. Salmonella Weltevreden was the predominant serovar in both chickens and humans. NTS isolates showed resistance (20–40%) against tetracycline, chloramphenicol, sulfamethoxazole‐trimethoprim and ampicillin. Our study reflects the epidemiology of NTS colonization in chickens and humans in the Mekong delta of Vietnam and emphasizes the need of larger, preferably longitudinal studies to study the transmission dynamics of NTS between and within animal and human host populations.     

Successful treatment of infectious (Salmonella type III: 44) polyarthritis and osteomyelitis in a 4‐week‐old foal

This article describes the acute onset of infectious polyarthritis and osteomyelitis in a 4‐week‐old foal. Analysis of synovial fluid obtained from the left femoropatellar and right tarsocrural joints combined with clinical signs consisting of joint effusion and lameness yielded a diagnosis of septic arthritis. Bacterial culture of synovial fluid from the left stifle revealed Salmonella type III: 44. Rapid, sustained clinical improvement was noted following discontinuation of empirical antimicrobial therapy (potassium penicillin and amikacin sulphate) and initiation of treatment with ceftiofur and ampicillin. The importance of combining knowledge of veterinary pharmacology and microbiology so that appropriate antimicrobials may be selected with regard to the local environment in which they are to eradicate infection is emphasised. Despite frequent reference to amikacin sulphate as an effective antimicrobial for treating infections in foals caused by Salmonella, factors are discussed that explain why amikacin may not be clinically effective for treating infectious arthritis caused by Salmonella.     

The effect of amino acid restriction during the grower phase on compensatory growth, carcass composition and nitrogen utilisation in grower–finisher pigs

Three hundred and ninety six pigs weighing 42 kg (s.d. +/− 2.5 kg), (progeny of Landrace × Large White sows × Meatline boars) (216 boars and 180 females) were assigned to four dietary treatments to determine the effects of restricting dietary lysine during the grower period (approximately 42 to 63 kg) on nitrogen (N) intake, retention and excretion during the finisher period (approximately 63 kg to slaughter at 94 kg). Two experiments, a performance experiment (nine replicates/treatment) and a N balance experiment (four replicates/treatment) were carried out. The experimental treatments were (1) 1.25% lysine from d 0 to d 28 and 1.05% lysine from d 29 to slaughter (HM), (2) 1.05% lysine from d 0 to slaughter (MM), (3) 0.85% lysine from d 0 to d 28 and 1.05% lysine from d 29 to slaughter (LM) and (4) 0.85% lysine from d 0 to slaughter (LL). All diets were pelleted and formulated to contain 13.8 MJ DE/kg. The pigs were group fed in mixed sex pens using single space feeders (11 pigs/feeder, 6 boars and 5 females). In the N balance experiment, sixteen entire male pigs, after 16 days on the diets were placed individually in metabolism crates and urine and faeces were collected. The pigs offered the 0.85% lysine diets during the grower period had a lower average daily gain (ADG) and a poorer feed conversion ratio (FCR) than the pigs offered 1.25% and 1.05% lysine diets (P < 0.05). During the early finisher period (days 29–42) and overall finisher period (days 29–56) pigs on treatment LM had a higher ADG (P < 0.01) and a better FCR (P < 0.05) than pigs on treatment LL. Pigs on treatment LM also had a better FCR than pigs on treatment HM and MM (P < 0.05) during the early finisher period. Pigs on treatment LM had a significantly (P < 0.05) higher lean meat proportion than pigs on treatment LL. During the grower N balance, pigs on the 0.85% lysine diets (treatments LM and LL) had lower N intakes (P < 0.001), N excretions (P < 0.001) and a higher (P < 0.001) nitrogen utilisation than pigs on treatments MM and HM. During the finisher N balance, pigs on treatment LL had a lower N intake (P < 0.001), N excretion (P < 0.01) and N retention (P < 0.05) than pigs on all other treatments. In conclusion, restricting dietary lysine during the grower period reduced growth rate but resulted in a more efficient growth during the early finisher period once dietary lysine was restored.     

Improvement of bacterial clearance and relief of clinical signs of Salmonella enterica serovar Typhimurium infection in pigs through upregulation of Th 1-specific responses by administration of a combination of two silicate minerals,biotite and bentonite

Biotite and bentonite are phyllosilicate minerals that were originally used inindustrial applications. Several beneficial activities of them have recently beenreported, especially regulation of the immune system and antimicrobial effects. Therefore,we investigated the immune-enhancing and bacterial clearance effects of a biotite andbentonite mixture (BBM) on experimental infection of Salmonella entericaserovar Typhimurium (S. Typhimurium) to determine whether the BBM couldbe used as an alternative antibiotic. We administered 1% or 2% BBM as a feed supplement.We then evaluated the bacterial clearance effects of the BBM against S.Typhimurium. We also evaluated the immune-enhancing effect of the BBM through severalimmunological experiments that included examination of the lysozyme activity,CD4⁺/CD8⁺ T lymphocyte ratio and the T-helper type 1 (Th 1)cytokine profile. The clinical signs of S. Typhimurium and the number ofviable bacteria in feces and tissues were significantly decreased in both BBM groups,especially in the 2% BBM group. The BBM also markedly enhanced the lysozyme activity,CD4⁺/CD8⁺ T lymphocyte ratio and expression levels of IFN-γ andIL-12 in S. Typhimurium-challenged pigs. Therefore, the BBM could be agood candidate as an alternative antibiotic that improves Th 1-specific immune responsesand the bacterial clearance effect.     

Prevalence of enteric non‐typhoidal Salmonella in humans in the Middle East and North Africa: A systematic review and meta‐analysis

To enhance efforts related to controlling foodborne pathogens in the Middle East and North Africa (MENA), information on epidemiology of non‐typhoidal Salmonella enterica (hereafter termed “Salmonella”) is limited. We quantified the overall regional and country‐specific Salmonella prevalence in different human populations and identified the most common serotypes. Published literature of Salmonella prevalence was systematically reviewed and reported following the Preferred Items for Systematic Reviews and Meta‐Analysis (PRISMA) guidelines. Pooled Salmonella prevalence measures were estimated using a random‐effects model. We identified 46 research reports that reported 84 Salmonella prevalence measures in 15 out of 24 countries in MENA. There were 252,831 tested humans with 6,356 Salmonella‐positive cases. The pooled Salmonella prevalence in MENA was estimated at 6.6% (95% confidence interval (CI): 5.4%–7.9%). The highest pooled Salmonella prevalence measures were in Morocco (17.9%, 95% CI: 5.7%–34.8%, 1997–2012), Tunisia (10.2%, 95% CI: 4.3%–18.0%, 1988–2009) and Sudan (9.2%, 95% CI: 6.5%–12.2%, 2006–2008), while the lowest were in Jordan (1.1%, 95% CI: 0.1%–3.0%, 1993–2010), Oman (1.2%, 95% CI: 1.2%–1.3%, 1998–2002) and Palestine (1.2%, 95% CI: 0.4%–2.1%, 1999–2011). In MENA, Salmonella pooled prevalence in gastrointestinal symptomatic, gastrointestinal asymptomatic and food handlers population groups was 13.0% (95% CI: 7.6%–19.6%), 11.4% (95% CI: 2.2%–25.7%) and 3.8% (95% CI: 1.0%–8.0%), respectively. Salmonella prevalence was 14.5% (95% CI: 8.7%–26.1%) in studies tested <100 subjects, whereas 4.6% (95% CI: 3.6%–5.8%) in studies tested ≥100 subjects. Salmonella Enteritidis (29.8%) and Typhimurium (23.6%) were the most common serotypes. Salmonella was a common foodborne pathogen in MENA countries, particularly in North African countries. Findings inform the scientific community, the public and the decision‐makers with Salmonella prevalence and gaps in evidence in MENA to support control and prevention strategies and could leverage more research studies.     

Genetic diversity,anti‐microbial resistance,plasmid profile and frequency of the Vi antigen in Salmonella Dublin strains isolated in Brazil

Salmonella Dublin is strongly adapted to cattle causing enteritis and/or systemic disease with high rates of mortality. However, it can be sporadically isolated from humans, usually causing serious disease, especially in patients with underlying chronic diseases. The aim of this study was to molecularly type S. Dublin strains isolated from humans and animals in Brazil to verify the diversity of these strains as well as to ascertain possible differences between strains isolated from humans and animals. Moreover, the presence of the capsular antigen Vi and the plasmid profile was characterized in addition to the anti‐microbial resistance against 15 drugs. For this reason, 113 S. Dublin strains isolated between 1983 and 2016 from humans (83) and animals (30) in Brazil were typed by PFGE and MLVA. The presence of the capsular antigen Vi was verified by PCR, and the phenotypic expression of the capsular antigen was determined serologically. Also, a plasmid analysis for each strain was carried out. The strains studied were divided into 35 different PFGE types and 89 MLVA‐types with a similarity of ≥80% and ≥17.5%, respectively. The plasmid sizes found ranged from 2 to >150 kb and none of the strains studied presented the capsular antigen Vi. Resistance or intermediate resistance was found in 23 strains (20.3%) that were resistant to ampicillin, ciprofloxacin, chloramphenicol, imipenem, nalidixic acid, piperacillin, streptomycin and/or tetracycline. The majority of the S. Dublin strains studied and isolated over a 33‐year period may descend from a common subtype that has been contaminating humans and animals in Brazil and able to cause invasive disease even in the absence of the capsular antigen. The higher diversity of resistance phenotypes in human isolates, as compared with animal strains, may be a reflection of the different anti‐microbial treatments used to control S. Dublin infections in humans in Brazil.     

Evaluation of Pet‐Related Management Factors and the Risk of Salmonella spp. Carriage in Pet Dogs from Volunteer Households in Ontario (2005–2006)

The purpose of this study was to determine pet‐related management factors that may be associated with the presence of Salmonella spp. in feces of pet dogs from volunteer households. From October 2005 until May 2006, 138 dogs from 84 households in Ontario were recruited to participate in a cross‐sectional study. Five consecutive daily fecal samples were collected from each dog and enrichment culture for Salmonella spp. was performed. A higher than expected number of the dogs (23.2%; 32/138) had at least one fecal sample positive for Salmonella, and 25% (21/84) of the households had at least one dog shedding Salmonella. Twelve serotypes of Salmonella enterica subsp. enterica were identified, with the predominant serotypes being Typhimurium (33.3%; 13/39), Kentucky (15.4%; 6/39), Brandenburg (15.4%; 6/39) and Heidelberg (12.8%; 5/39). Univariable logistic regression models were created with a random effect for household to account for clustering. Statistically significant risk factors for a dog testing positive included having contact with livestock, receiving a probiotic in the previous 30 days, feeding a commercial or homemade raw food diet, feeding raw meat and eggs, feeding a homemade cooked diet, and having more than one dog in the household. In two‐variable models that controlled for feeding raw food, the non‐dietary variables were no longer statistically significant. These results highlight the potential public health risk of including raw animal products in canine diets.     

The pupillary light reflex and menace response in neonatal calves: the role of environmental isolation on development of the menace response

The aim of this study was to investigate the development of the pupillary light reflex in neonatal calves and the effect on the development of the menace response of keeping them in individual stalls. Seventy-three Holstein calves were divided into test (n = 44) and control (n = 29) groups and the animals were kept in individual stalls for the first 32 ± 4 and 73 ± 5 days post partum, respectively. They were then moved to group pens. All calves in both groups were observed daily from the first day after birth until the pupillary light reflex and menace response had become well established.All 73 calves had a positive pupillary light reflex on the first day post partum. None of the animals developed a menace response during the time they were housed in individual stalls. Over 14 days (test group) and 12 days (control group) after the calves had been moved to the group pens they became positive to the menace response at ages 41 ± 4 and 81 ± 5 days, respectively. The Mann–Whitney test revealed a significant difference (P < 0.001) in the ages of the calves with positive menace responses between groups. Group rearing may produce more visual threats to the eyes and the calves learn the menace response by closing the lids in response to sudden alarming movements.     

Changes in the risk management of Salmonella enterica subspecies diarizonae serovar 61:(k):1, 5, (7) in Swedish sheep herds and sheep meat due to the results of a prevalence study 2012

Background

The prevalence of Salmonella in food producing animals is very low in Sweden due to rigorous control programmes. However, no active surveillance is in place in sheep. The authorities decided to perform a prevalence study in sheep herds because findings at slaughter indicated that sheep associated S. diarizonae (S. enterica subspecies diarizonae serovar 61:(k):1, 5, (7)) might be common in sheep. Sampling was stratified by herd size in two groups, small herds with ≤ 30 animals and large herds with > 30 animals. In each stratum, 237 herds were selected at random. Faecal samples received from 244 out of the 474 randomly selected herds were analysed.

Results

A total of 40 of 100 (40%) of large herds and 17 of 144 (12%) of small herds were positive. The overall adjusted prevalence was 17.6% (95% CI, 12.9-22.2). Sheep associated S. diarizonae was detected in all counties (n = 21). Scientific opinions and an evaluation of on-farm control measures performed concluded that the impact of sheep associated S. diarizonae on human health is very low, and that risk management measures applied in response to findings of sheep associated S. diarizonae in sheep or sheep meat can be expected to have very little impact on reducing risks to human health. As a result, Swedish authorities decided to make an exemption for sheep associated Salmonella diarizonae in sheep and sheep meat in the current Salmonella control measures.

Conclusions

Sheep associated S. diarizonae is endemic in Swedish sheep herds. It is more common in large herds and not limited to certain parts of the country. The responsible authorities concluded that current risk management actions regarding sheep associated S. diarizonae in sheep and sheep meat are not proportional to the risk. This is the first time in the history of the Swedish Salmonella control programme that an exemption from the legislation has been made for a specific serovar. If there is any future indication of an increasing risk, due to e.g. change in the pathogenicity or development of antimicrobial resistance, the risk assessment will be re-evaluated and control measures reinforced if needed.     

The effects of the supplementation of multi‐strain probiotics on intestinal microbiota,metabolites and inflammation of young SPF chickens challenged with Salmonella enterica subsp. enterica

This study assessed the effect of probiotics on cecal microbiota, cecal short‐chain fatty acids (SCFAs), and the gene expression of cytokines in young specific‐pathogen‐free (SPF) chickens infected with S. enterica subsp. enterica. One‐day‐old SPF chickens (n = 105) were randomly assigned to one of the three treatment groups: control (Cont) group, Salmonella‐infected (Sal) group, and a Salmonella‐infected group treated with multi‐strain probiotics (ProSal group). All chickens except those in the Cont group were challenged orally with 1 × 10⁸ cfu/ml of Salmonella 4 days after hatching. Chickens in the Sal group exhibited more abundance of Proteobacteria than those in the Cont and ProSal groups. At the genus level, chickens in ProSal group exhibited increased numbers of Lactobacillus and Oscillospira compared with those in the other groups. Chickens in the ProSal group exhibited a significant increase of cecal SCFAs compared with chickens in the Sal group. Chickens in the ProSal group exhibited increased gene expression of anti‐inflammatory cytokines, IL‐10 and TGF‐β4, and decreased expression of the proinflammatory cytokine, IFN‐γ, in the cecal tonsil compared with those in the Sal group. The results of this study indicated that the administration of probiotics can modulate microbiota, SCFAs, and immunomodulatory activity in SPF chickens.     

Phage and MLVA Typing of Salmonella Enteritidis Isolated from Layers and Humans in Belgium from 2000–2010, A Period in which Vaccination of Laying Hens was Introduced

The aim of the study was to characterize isolates of Salmonella enterica serovar Enteritidis (S. Enteritidis) obtained from humans and layer farms in Belgium collected during 2000–2010. Three periods were compared, namely (i) before implementation of vaccination (2000–2004), (ii) during voluntary vaccination (2005–2006) and (iii) during implementation of the national control program (NCP) for Salmonella including mandatory vaccination against S. Enteritidis (2007–2010). The characteristics compared across time periods were distributions of phage type and multiple‐locus variable number tandem‐repeat assay (MLVA). While PT4 and PT21 were predominantly isolated in Belgium in layers and humans before 2007, a significant reduction of those PTs was observed in both populations in the period 2007–2010. The relative proportion of PT4b, PT21c and PT6c was found to have increased considerably in the layer population since 2007. In the human population, PT8, PT1 and the group of ‘other’ PTs were more frequently isolated compared to the previous periods. When comparing the proportion of the predominant MLVA types Q2 and U2, no significant difference was found between the layer and human population in the three periods and between periods within each category (layer and human). A significant difference in isolate distribution among MLVA clusters I and II was found between human and layer isolates recovered during Period 3 and in the human population between Period 1 and 3. Results suggest that the association between S. Enteritidis in layers and the occurrence of the pathogen in humans changed since implementation of the NCP in 2007.