Search

Few studies have examined sows and piglets' use of outdoor access during their first weeks of life, when reared with access to a hut and a pasture as in the organic system. We studied whether the age of the piglets and the season of the year influenced the use of an outdoor area by piglets and the sow, and the use of indoor spaces. For this, the localisation of sows and their piglets inside and outside the hut was analysed on 16 sows and their litters during the summer and 16 others during the winter, by scan sampling, on days 2, 7 and 13 after parturition in an organic herd in Denmark. When inside the hut, the number of piglets in the creep area, next to the sow or other piglets was noted. All parameters were analysed by linear mixed-effects ANOVA models. Sows were less often observed outside the hut in the wintertime and during the mornings compared to later times of the day (P<0.001). Furthermore, the sows increased their outdoor use with the age of their litter (P<0.001). The season also influenced the piglet use of outdoor areas (winter < summer; P<0.001). Piglets that were observed outside for the first time were older (8.9±0.9 d) during winter than during summer (3.5±0.5 d). The proportion of piglets observed outside increased with age, with a significant Season x Age interaction (P<0.001). The proportion of observations where the sows and piglets were outdoors together increased with the piglets' age (P < 0.001). Sows' outing was correlated with summer (R=0.3) and winter (R=0.2) temperatures, unlike piglets, where outings were correlated only with summer temperatures (R=0.3, P<0.001). The proportion of piglets observed in the creep area was significantly affected by the age with a Season x Age interaction effect (P<0.001). Piglets were rarely observed lying alone inside the hut. The proportion of piglets in contact with the sow and other piglets inside the pen was influenced by a significant Age x Season interaction effect (P<0.001). We showed that piglets given access to an outside paddock gradually increase their use with age and don't go outside right away. Their first exit and the proportion of piglets outside depended also on the season. In general, a higher proportion of sows and piglets were observed indoor during the wintertime. Thus, sows and piglets adjust their use of outdoor paddock with season and piglet age during the first weeks of life. • Piglets adjust their use of outdoor paddock according to season and age. • Outdoor use by sows, with or without their piglets, increased with piglets' age. • The first observation of piglets outside was later in winter than in summer. • Use of creep area depended on Season x Age interaction. • Contact between the sow and other piglets inside the hut depended on Season x Age. [ABSTRACT FROM AUTHOR]

The purpose of the paper is to highlight the reproductive performance obtained in a pig farm in Denmark following the treatment of sows with a hormonal preparation used to synchronize oestrus. The research involved the study of 105 YL (Yorkshire x Landrace) cross-breed females, all between the ages of 28 and 30 weeks, weighing between 100 and 120 kg, exploited for the production of bacon. The following indicators were followed: fertility, index of use of sows for reproduction, prolificacy, number of piglets weaned on female and piglets' mortality. The obtained results showed higher values for all the indicators analysed at the batch treated with the hormonal preparation compared to the control group (fertility 94.99 vs 91.66%; the index of use of sows for reproduction 2.47 vs 2.29; prolificacy 16.7 vs 15.6 piglets; number of weaned piglets on female 15.7 vs 15 piglets). The results of the study demonstrate that hormone treatment in sows leads to improvement of reproduction indicators in sows. [ABSTRACT FROM AUTHOR]

Until recently, the pre-slaughter logistic chain of cull sows had received limited study, and their behaviour during transport remains understudied. Previously, an observational study of journeys up to 8 h in Denmark showed that the clinical condition of sows had deteriorated from departure until arrival at the slaughterhouse. The suggested main risk factors for this were journey duration, in-vehicle temperature and stationary periods, often in interaction. To disentangle these risk factors, we performed a 3 × 2 factorial study simulating commercial conditions of varying journey durations (4 h, 6 h, 8 h) and the presence of a stationary period of 30–50 min after 1–4 h of driving (long stop: yes/no). In 28 vehicle loads of sows from six herds, behaviour (posture and aggression) and in-vehicle temperature were recorded in the rear compartment holding 11–12 sows during transport to a Danish slaughterhouse. Unexpectedly, the sows were generally standing during transport (median 89–92% standing sows per hour). More sows were standing in the initial hours compared to later. Fewer sows were standing when in-vehicle temperature was higher and with higher temperature standard deviation per hour. We found that fewer sows were standing during the long stop when the latency until the long stop was longer. There was variation in the frequency of aggression among sows (median 2–3, range: 0–155 events per sow), but no differences were detected in the rate of aggression as an effect of time since departure, the presence of a long stop, or in-vehicle temperature. The frequency of aggression received per sow positively correlated with number of scratches on the front of the sow (r = 0.24). Comparing the present results with the scientific literature on finisher pigs, cull sows seem to differ in their tendency to remain standing and show aggressive behaviour throughout journeys to the slaughterhouse. We discuss possible explanations including the pre-transport clinical condition of cull sows, their sensitivity to heat stress and mixing of unfamiliar animals in a confined space as well as the experimental design choice of observing sows in the rear compartment of the vehicle. In conclusion, contrary to expectations, sows were generally standing during transport, and aggression was found throughout the journeys. The higher proportion of sows lying down during a long stop with longer time until the stop may suggest fatigue. These initial findings on the behaviour of cull sows during transport suggest challenges to their welfare. • To our knowledge, the first description of cull sow behavior during transport. • Journeys of 4 h, 6 h and 8 h with and without a long stop was investigated. • The sows were generally standing during transport irrespective of journey duration. • The proportion of standing sows was lower with higher temperature inside the vehicle. • The rate of aggression did not change as an effect of time since departure. [ABSTRACT FROM AUTHOR]

Influenza A virus (IAV) is a highly contagious pathogen in pigs. Swine IAV (swIAV) infection causes respiratory disease and is thereby a challenge for animal health, animal welfare and the production economy. In Europe, the most widespread strategy for controlling swIAV is implementation of sow vaccination programs, to secure delivery of protective maternally derived antibodies (MDAs) to the newborn piglets. In this study we report a unique case, where a persistently swIAV (A/sw/Denmark/P5U4/2016(H1N1)) infected herd experienced an acute outbreak with a new swIAV subtype (A/sw/Denmark/HB4280U1/2017(H1N2)) and subsequently decided to implement a mass sow vaccination program. Clinical registrations, nasal swabs and blood samples were collected from four different batches of pigs before and after vaccination. Virus isolation, sequencing of the virus strain and hemagglutinin inhibition (HI) tests were performed on samples collected before and during the outbreak and after implementation of mass sow vaccination. After implementation of the sow mass vaccination, the time of infection was delayed and the viral load significantly decreased. An increased number of pigs, however, tested positive at two consecutive sampling times indicating prolonged shedding. In addition, a significantly smaller proportion of the 10–12 weeks old pigs were seropositive by the end of the study, indicating an impaired induction of antibodies against swIAV in the presence of MDAs. Sequencing of the herd strains revealed major differences in the hemagglutinin gene of the strain isolated before- and during the acute outbreak despite that, the two strains belonged to the same HA lineage. The HI tests confirmed a limited degree of cross-reaction between the two strains. Furthermore, the sequencing results of the hemagglutinin gene obtained before and after implementation of mass sow vaccination revealed an increased substitution rate and an increase in positively selected sites in the globular head of the hemagglutinin after vaccination. [ABSTRACT FROM AUTHOR]

The objective of the current study was to determine the optimal concentration of dietary standardized ileal digestible (SID) Lys required to maximize litter gain and minimize sow BW loss in modern high-yielding lactating sows when SID CP was kept constant across dietary treatments. A total of 396 parity 1 to 5 sows (L × Y, DanBred, Herlev, Denmark) were included in the study from day 3 after farrowing until weaning at day 26. Sows were allocated to 6 dietary treatments increasing in SID Lys concentration (6.19, 6.90, 7.63, 8.33, 9.04, and 9.76 g/kg). Diets were isoenergetic (14.04 MJ ME/kg as-fed). Litters were standardized to 14 piglets at day 3 ± 2 d postpartum. At day 3 ± 2 d and at day 26 ± 3 d in lactation, litter weight, and sow BW and back fat were registered. On a subsample of 72 parity 2 to 4 sows, litters were additionally weighed at days 10 and 17 ± 3 d, and milk and blood were sampled at day 3 ± 2 d, and 10, 17 and at 24 ± 3 d in lactation. For the 72 sows, body pools of fat and protein were also determined at days 3 ± 2 and 26 ± 3 d using the D2O dilution technique. All data were analyzed as a randomized complete block design using PROC MIXED in SAS. Furthermore, data were subjected to linear and quadratic polynomial contrasts. Variables with quadratic or linear effects or days in milk × treatment interactions were selected for analysis in PROC NLMIXED using linear broken-line models to evaluate optimal SID Lys concentrations. Only models that converged and the best fitting models were included. Average daily litter gain increased until a breakpoint at 8.11 g/kg of SID Lys (as-fed). At and above the breakpoint, multiparous and primiparous sows had litter gains of 3.36 and 2.93 kg/d, respectively. Weaning litter size (13.0 ± 0.1) was similar between the 6 dietary treatments (P = 0.28). Lactation sow BW loss was minimized to 0.17 kg/d at 9.05 g/kg of SID Lys and sow body protein loss was minimized to 0.23 kg at 9.22 g/kg of SID Lys. Linear broken-line analyses showed that for 3, 10, 17, and 24 DIM, plasma urea was minimized at 7.02, 8.10, 8.73, and 8.32 g/kg of SID Lys, respectively, and milk fat was maximized at 7.80 g/kg of SID Lys. In conclusion, in our conditions, high-yielding lactating sows required 8.11 g/kg of SID Lys to maximize litter gain and 9.05 g/kg of SID Lys to minimize sow BW loss. Based on plasma urea, the optimal dietary concentration of SID Lys was lowest in week 1, intermediate in week 2 and 4, and greatest in week 3 of lactation. [ABSTRACT FROM AUTHOR]

The objective of the current study was to determine the requirement of standardized ileal digestible (SID) CP for maximal litter gain in high-yielding lactating sows due to insufficient supply of either His, Leu, Val, Ile, or Phe. The content of SID Lys was formulated at 95% of the recommended level, while that of Met, Met+Cys, Thr, and Trp was formulated at 100% of the recommended level or slightly greater using crystalline AA. A total of 540 parity 1 to 5 sows (L×Y, DanBred, Herlev, Denmark) were included in the study from day 3 after farrowing until weaning at day 26. Sows were allocated to six dietary treatments increasing in SID CP content (96, 110, 119, 128, 137, and 152 g/kg). Litters were standardized to 14 piglets at day 3 ± 2 after farrowing. At day 3 ± 2 after farrowing and at day 26 ± 3, sow BW and back fat, and litter weight were recorded. On a subsample of 72 sows (parity 2 to 4), litters were also weighed at days 10 and 17 ± 3, and milk and blood were sampled at day 3 ± 2 d, and 10, 17 and at 24 ± 3 d in lactation. Sow body pools of protein and fat were determined on the 72 sows at days 3 ± 2 and 26 ± 3 d using the D2O dilution technique. All data were subjected to ANOVA, and to linear and quadratic polynomial contrasts. Variables with quadratic effects or days in milk × treatment interactions were analyzed using linear regression or one-slope linear broken line using the NLMIXED procedure of SAS. Average daily litter gain reached a breakpoint at 125 g SID CP/kg (as-fed). Multiparous sows had a greater litter gain than primiparous sows (3.33 vs. 3.02 kg/d above the breakpoint; P < 0.001) but litter size (13.1 ± 0.1) at weaning were unaffected by dietary treatment (P = 0.62). Sow BW loss was minimized at 102 g SID CP/kg. Concentrations of protein and casein in milk increased linearly with increasing SID CP (P < 0.001). Milk urea reached a minimum at 111–118 g SID CP/kg (P < 0.05) and milk fat a maximum at 116 g SID CP/kg (P < 0.05). In conclusion, 125 g SID CP/kg feed was required to maximize litter gain. [ABSTRACT FROM AUTHOR]

• Animal welfare and a reduced usage of antibiotics in pig herds can go hand in hand. • Systemic conditions play major roles in antibiotic usage in pig herds. • Prudent use of antibiotics in pigs is challenged by uneducated employees. • Regulations on antibiotics in pig herds feels both helpful and counterproductive. • Hyperprolific sows challenge the agenda on prudent use of antibiotics. The usage of antibiotics in pig production is much debated due to the risk for antimicrobial resistance where routine usage is necessary to protect animal welfare. Denmark has a relatively low usage of antibiotics in pigs. Thus, the Danish context provides critical insight on how to achieve a lower usage of antibiotics in pigs, and experiences from Danish farmers and veterinarians are useful when debating possibilities for reduction. In this study, we conducted semi-structured interviews with ten pig farmers and six pig veterinarians in Denmark to examine how they perceived animal welfare to be affected in herds where the usage of antibiotics or pZnO had been reduced. The study aimed to explore dilemmas and difficulties in relation to protection of animal welfare while having a low usage of medicine. The interviews were conducted in spring 2022, thus, prior to the ban on pZnO in June 2022. We found that the participants in the study had many positive experiences with achieving a lowered need for antibiotics and pZnO. By upgrading on feeding and management and focusing on prevention of diseases, many herds had succeeded in lowering the usage of medicine with no harmful effect on animal welfare. Many years of strict regulatory measures was highlighted as a major reason for this success, but other contextual factors such as production within the "Pure Pork" concept, which provides an economic reward for pigs raised without use of antibiotics, were also acknowledged to play a positive role. The study illustrated how antibiotics are an integrated part of everyday practice in pig herds. Systemic conditions like difficult employee situations, breeding for high prolificacy and bad economy came forward as major explanations for usage of antibiotics. The study also pointed out how antibiotics were sometimes used routinely and thereby highlighted how reductions should still be achievable. Examples were systematic injections to all piglets at birth and to sows post farrowing. In some cases, routine use was explained by having many employees in the pig herds with no education in how to take care for pigs or how to recognize disease. Avoiding pen or batchwise medication of weaners and thereby avoid treatment of healthy animals was a point of controversy, putting spotlight on grey zones and challenges between productivity and animal welfare. [ABSTRACT FROM AUTHOR]

The objective was to investigate the variation in backfat at weaning and its relations to reproduction results in organic sow herds in Denmark. The study included eight herds and 573 sows. The average backfat at weaning (mean = 13 mm; SD = 4.2 mm) ranging from 10.5 to 17.3 mm among herds shows that it is possible to avoid poor body condition at weaning even with a lactation length of seven weeks or more. No main effect of backfat at weaning on reproduction performance was found, but the probability of a successful reproduction after weaning tended to decrease with decreasing backfat for first parity sows, whereas the opposite was the case for multiparous sows. [ABSTRACT FROM AUTHOR]

Simple Summary: Over recent decades, the number of piglets and, therefore, the number of stillborn piglets per litter have been increasing. Blood and oxygen supply are crucial for piglets to survive the birth process. Blood flow might be increased through vasodilation by dietary nitrate supplementation, which is known in sports nutrition to increase endurance. The current study evaluated the effects of nitrate supplementation to sows on the incidence of stillbirth at a commercial farm. In total, 120 sows received either a control diet or a diet containing 0.1% of calcium nitrate from approximately 5 days until 4 days after farrowing. The number of piglets born alive, stillborn, or that died from birth to weaning were recorded. Piglets were weighed at birth, after cross-fostering, 24 h after cross-fostering, at 3 days of age, and at weaning. Placentas were collected after expulsion and were visually scored on redness. No effect of nitrate supplementation to the sow was found on placental redness, piglet weights, and growth or incidence of death after being born. Dietary nitrate supplementation decreased the stillbirth percentage from 9.9 to 7.4%, making it a potential approach to decrease stillbirth. The objective of the current experiment was to investigate whether or not maternal dietary nitrate supplementation, a nitric oxide (NO) precursor, could reduce piglet losses under commercial circumstances. In the current experiment, 120 hyper prolific gilts and sows (Landrace x Yorkshire: Danbred) on a commercial farm in Denmark received either a control lactation diet or a lactation diet containing 0.1% of calcium nitrate (containing 63.1% of nitrate) from approximately 5 days pre-farrowing until day 4 of lactation. The number of piglets born total, alive, and stillborn, as well as birth weights, weights after cross-fostering (approximately 1 day of age), 24 h after cross-fostering, day 3 of age, and at weaning was recorded. Placentas of sows were collected after expulsion and scored on redness. No effect of nitrate supplementation was found on piglet weight, piglet growth, placental redness score, and pre-weaning mortality during lactation. Maternal dietary nitrate supplementation decreased stillbirth percentage with 2.5% (9.9 vs. 7.4%; p = 0.05). It can be concluded that maternal dietary nitrate supplementation shows the potential to decrease the incidence of stillbirth in hyper prolific sows. [ABSTRACT FROM AUTHOR]

The article ponders whether loose housing of sows in Denmark connotes good welfare. The reasons behind the popular use of crates as a housing method for sows are explained including its importance to behaviour control. Sows in loose housing are said to be provided with better welfare than stall housing when electronic sow feeding (ESF) or one eating stall per sow (OESPS) systems are well designed and management is good. It points out the importance of adequate attention to the complexity of the animal and its housing system.

Background: Joint lesions occur widespread in the Danish sow population and they are the most frequent cause for euthanasia. Clinically, it is generally impossible to differentiate between various types of non-inflammatory joint lesions. Consequently, it is often necessary to perform a post mortem examination in order to diagnose these lesions. A study was performed in order to examine the relation of abnormal gait and posture in sows with specific joint lesions, and thereby obtaining a clinical diagnostic tool, to be used by farmers and veterinarians for the evaluation of sows with joint problems. Methods: The gait, posture and lesions in elbow- and knee joints of 60 randomly selected sows from one herd were scored clinically and pathologically. Associations between the scorings were estimated. Results: The variables 'fore- and hind legs turned out' and 'stiff in front and rear' were associated with lesions in the elbow joint, and the variables 'hind legs turned out' and 'stiff in rear' were associated with lesions in the knee joint. Conclusion: It was shown that specified gait and posture variables reflected certain joint lesions. However, further studies are needed to strengthen and optimize the diagnostic tool. [ABSTRACT FROM AUTHOR]

Background: The aims of the present work was to study whether there are any relationships between cortisol and PG-metabolite in mated sows or inseminated with the intrauterine technique and compare these to changes occurring in conventionally inseminated sow. Methods: Thirty three crossbred sows (Danish Landrace x Danish Large White) were fitted with jugular vein catheters through vena auricularis from one of the ears. The sows were randomly divided into three groups (Boar-, IUI- and AI-group) and blood samples were collected before, during and after service. In a final evaluation only 25 sows that became pregnant and farrowed piglets at full term were used. Results: Cortisol concentrations increased in all groups but Boar-group (n = 8) had a significantly higher cortisol during 10 to 20 min after service than sows in AI-group (n = 8). In mated sows cortisol concentrations peaked at 15 minutes after service. The Boar-group (n = 8) showed no ascending PG-metabolite levels during the whole experiment, while both IUI- and AI-groups (n = 9 and n = 8, respectively) had a 2.5-fold increase in PG-metabolite 15 minutes after service. Conclusion: In conclusion, mating of sows by a boar results in a greater increase of cortisol than AI and without an elevation of PG-metabolite levels, which was seen in both the inseminated groups. It was also demonstrated that IUI-group had an earlier significant increase of PG-metabolite levels than sows inseminated conventionally. Further investigation using different semen extenders or even different type of insemination catheters might be helpful in understanding the reason for an immediate increase of PG-metabolite after insemination but not after mating. [ABSTRACT FROM AUTHOR]

We investigated the prevalences and intercorrelations of all daily meat-inspection recordings at four Danish sow abattoirs in the year 2000 from 23,794 sows coming from 207 sow or farrow-to-finisher herds. The meat-inspection data were obtained from databases at the Danish Bacon and Meat Council (DBMC). Prevalences generally were low—but large herd-to-herd variations were seen. Despite low prevalences, many slaughtered sows had recordings which raise welfare concerns. Intercorrelations between the meat-inspection recordings were evaluated using exploratory factor analysis describing underlying latent factors related to health and welfare problems within herds. [Copyright &y& Elsevier]

In recent years, there has been a considerable increase in the use of Modified Live PRRSV Vaccines (MLV) for mass vaccination in Denmark. The potential risks and negative impact of this strategy have been sparsely studied. The aim of this study was to investigate the impact of quarterly sow mass vaccination in two Danish sow herds. The study was performed as an observational prospective cohort of 120 sows in each of two commercial breeding herds in a paired design. Blood samples were taken from sows and oral fluid samples from nursery pigs (four to ten weeks old) before and after vaccination. The presence of PRRSV-1 RNA was measured by real time quantitative reverse transcription-polymerase chain reaction (RT-qPCR), and the level of PRRSV-1 specific antibodies was measured by two different serological assays. PRRS virus was not detected in the sow herds two days before and two weeks after vaccination, but the vaccine strain virus was detected in the nursery pigs. The prevalence of sows without antibodies towards PRRSV-1 went from 6–15% before vaccination to 1–4% after vaccination depending on the serological assay used, despite the fact that they had previously been repeatedly vaccinated. Four sows tested negative for antibodies in both assays after vaccination. [ABSTRACT FROM AUTHOR]

Simple Summary: Piglet mortality is an ongoing concern for pig production worldwide. Piglets that have a low piglet birth weight (PBW), suffer from intrauterine growth restriction (IUGR) or are born from litters with a high within-litter variation in PBW (CVPBW) have an increased risk of dying before weaning. IUGR piglets, CVPBW and a low PBW might be connected by the same risk factors, and in order to optimize fetal development in the litter, these risk factors should be identified. Free-access stall feeding, floor feeding and electronic sow feeding systems are commonly used feeding systems for gestating sows in Denmark. These systems differ in several points, including in sow competition at feeding. The nutritional status of the sow is important for fetal development, and so the feeding method during gestation is also expected to affect such development. Of the risk factors identified in this study, increasing litter size was considered the most critical. Only small differences were found between the feeding systems and these differed amongst groups. The results should inspire further investigation of those risk factors to clarify causes of the observed effects and what drives individual herd differences. This study aimed to identify risk factors affecting PBW, high CVPBW and the occurrence of IUGR piglets in 12 commercial Danish herds with hyperprolific sows using free-access stalls, floor or electronic sow feeding systems in the gestation unit. The following factors were investigated: the duration of previous lactation, the length of the interval from weaning to insemination, the length of gestation, litter size, parity, sow backfat thickness in late gestation and the type of feeding system in the gestation unit. The study included newborn piglets from 452 litters with the following production indicator averages: 21.3 piglets/L, 1235 g PBW, 22.9% CVPBW and 10.9% and 11.8% within-litter occurrence of severe and mild IUGR piglets, respectively. Increasing length of weaning-to-insemination interval decreased PBW by 25.8 g/day. For 2nd to 9th parity sows, each additional piglet in the litter increased CVPBW by 0.38%, the occurrence of severe IUGR piglets by 0.68% and mild IUGR piglets by 0.50%. Sows of 5th parity and older had a 1.39% higher CVPBW and 49.1 g lighter piglets compared with sows of 2nd to 4th parity. PBW was lower in one ESF herd, suggesting complex interactions that need to be further elucidated. The main critical risk factor observed was litter size. [ABSTRACT FROM AUTHOR]

Atypical porcine pestivirus (APPV) was first discovered in North America in 2015 and was later shown to be associated with congenital tremor (CT) in piglets. CT is an occasional challenge in some Danish sow herds. Therefore, we initiated an observational case control study to clarify a possible relationship between CT and APPV in Danish pig production. Blood samples were collected from piglets affected by CT (n = 55) in ten different sow herds and from healthy piglets in five sow herds without a history of CT piglets (n = 25), as well as one sow herd with a sporadic occurrence of CT (n = 5). APPV was detected by RT-qPCR in all samples from piglets affected by CT and in three out of five samples from piglets in the herd with a sporadic occurrence of CT. In the herds without a history of CT, only one out of 25 piglets were positive for APPV. In addition, farmers or veterinarians in CT-affected herds were asked about their experience of the issue. CT is most often seen in gilt litters, and a substantial increase in pre-weaning mortality is only observed in severe cases. According to our investigations, APPV is a common finding in piglets suffering from CT in Denmark. [ABSTRACT FROM AUTHOR]

Pigs are one of several host species for Toxoplasma gondii parasites, and consumption of infected pork may lead to toxoplasmosis in humans. We estimated seroprevalence in sows and finishers from conventional and organic herds in Denmark and discussed the strategies for reducing the risk from pork. We collected 447 blood samples from 59 herds, and additional meat-juice samples from 212 of the same pigs. Using a T. gondii IgG commercial ELISA test, we found 2% (95% CI = 0.4%–5%) apparent seroprevalence of T. gondii in conventional finishers, 11% (95% CI = 6%–17%) in organic finishers, 19% (95% CI = 11%–30%) in conventional sows and 60% (95% CI = 47%–72%) in organic sows. The odds of an animal testing positive for T. gondii was 16 times higher (95% CI = 4.6–74.3) in organic compared to conventional herds. The odds were 22 times higher (95% CI = 6.5–88.3) if the animal was a sow compared to a finisher. Meat-juice ELISA values were significantly correlated with plasma results (P < 0.001), but on average 64% of the blood-plasma ELISA values. Lowering the recommended cut-off from 20 to 13 percent positive values of the positive control for meat-juice ELISA, resulted in the meat-juice ELISA identifying 93% of the plasma positives as positive and 99% of the plasma negatives as negative. The time taken to detect one or more infected pigs from a T. gondii positive herd at slaughter was estimated using abattoir data on pigs (17,195,996) and batches (165,569) delivered to Danish abattoirs in 2018. The time to detection was affected by the seroprevalence, frequency at which the pigs were delivered, the number of samples tested per batch delivery and the batch sizes. Time to detection was long in conventional finisher herds due to low prevalence, and in sow herds because of intermittent delivery of a low number of sows. In organic finisher herds, time to detection was short due to medium prevalence and frequent delivery of a high number of finishers. Conventional finisher herds may be classified as low-risk, organic finisher herds as medium-risk, and conventional and organic sow herds as high-risk herds. Risk-mitigation strategies at processing plants (freezing or curing) or at the consumer level (heat treatment) for meat originating from high-risk herds, surveillance of medium-risk herds, and auditing for controlled housing (high biosecurity) in low-risk herds may be cost-effective alternatives to serological surveillance of all Danish pig herds. [ABSTRACT FROM AUTHOR]

Serological tests are routinely used to detect Toxoplasma gondii specific IgG antibodies in serum. Serological surveys of T. gondii show a medium to high prevalence in Danish indoor sows at the time of slaughter. However, little is known about when sows acquire T. gondii, and for how long they remain seropositive. Our focus was on quantifying the incidence rates in different age-cohorts and on investigating the T. gondii IgG antibody dynamics in sows. Four large Danish sow farms were longitudinally surveyed for 1 year. A total of 320 animals from 6, 12, 18, and 24-months age-cohorts were sampled at 5-week intervals. In total, 2989 plasma samples were tested using commercial enzyme linked immunosorbent assay (ELISA). The incidence rate in each of the four age-cohorts was calculated, and a time-to-event analysis was applied to the interval censored data to investigate the relationship between age and probability of T. gondii seroconversion. In the initial ELISA testing, eight sows tested positive for T. gondii at first survey, of which seven remained seropositive throughout the follow-up period. Additionally, 16 sows seroconverted, but only five of these remained seropositive. Weekly incidence rates in the 6, 12, 18, and 24-month age-cohorts were 0.0017 (95% CI = 0.0008 - 0.0037), 0.0009 (95% CI = 0.0003 - 0.0027), 0.0003 (95% CI = 0.0000 - 0.0018), and 0.0023 (95% CI = 0.0010 - 0.0051), respectively. Time-to-event analysis suggested that the incidence rate increased with age but could not conclude this definitively. The retesting of a subsample of the sows (n = 200) with the same ELISA and with modified direct agglutination test (MAT), and western blot (WB) assays suggested that 12 out of the 24 initial ELISA seropositive sows may have been false positive. These 12 sows also showed fluctuating antibody dynamics in ELISA. Hence, the unstable antibody dynamics in ELISA may pose a challenge for serological surveys of T. gondii in sows., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Toxoplasma gondii is found worldwide, and consumption of undercooked meat is considered a significant risk factor for human infections. In Denmark, little is known about the distribution of T. gondii, but a recent study revealed a seroprevalence of 34% in Danish indoor sows. The present cross-sectional study aimed to investigate the role of mice for the transmission of T. gondii in Danish indoor sow herds. Results: In total, 56 sow herds were visited, 137 mice were caught by snap traps from 32 farms, and 52 cat faecal samples were collected from 22 farms. Eight percent of the mice were positive for T. gondii DNA, representing 11% of the farms. Significant associations were found between the presence of T. gondii-positive mice and both open feed systems (P= 0.041) and extra rodent control on the farm (P= 0.024). All cat faecal samples were deemed negative for T. gondii by light microscopy examination and real-time polymerase chain reaction analysis. Conclusion: Mice captured inside Danish sow herds were found to be infected with T. gondii and may thus contribute to the transmission of T. gondii to sows, which may explain the high seroprevalence found in Danish pigs. [ABSTRACT FROM AUTHOR]