Objective: This field study aimed to evaluate the effect of cross-fostering on the porcine reproductive and respiratory syndrome virus (PRRSV) transmission within litters. Materials and methods: A breed-to wean farm was selected 15 weeks after a PRRSV outbreak with a L1C.5 strain. Litters included in the study had all piglets individually identified and sampled. Litters were classified as positive when at least one piglet tested positive (PRRSV-2 RNA by quantitative reverse transcriptase-polymerase chain reaction). Cross-fostering was carried out within 48 hours after birth to establish five study groups: one positive piglet moved to a negative litter (n = 15), one negative piglet moved to a positive litter (n = 3), one negative piglet moved to a negative litter (n = 13), and two control groups without cross-fostering (positive litters, n = 5; negative litters, n = 14). All piglets were resampled prior to weaning. The increase in new PRRSV-positive piglets within litters was compared across study groups. Results: Compared to negative litters without cross-fostering, there was no difference in the increase of new PRRSV-positive piglets for groups where negative piglets were moved to either negative or positive litters or the group where a positive piglet was introduced into a negative litter. However, positive litters that did not receive any piglets had a significantly higher count of new PRRSV-positive piglets. Implication: Under the conditions of this study, cross-fostering did not influence the increase in new cases of PRRSV-positive piglets.
Objective: Evaluate the effects of practical alternative livestock trailer cleaning methods on inactivating porcine epidemic diarrhea virus (PEDV), thereby reducing the risk of PEDV introduction to farms via contaminated trailers during pig load out to terminal points of concentration. Materials and methods: Five cleaning methods were tested under experimental conditions: scrape and bake (SB), volume hose and disinfect (VHD), power wash and disinfect (PWD), positive control (PC, no cleaning), and negative control (NC, no PEDV challenge and no cleaning). Model-sized trailers were inoculated with a PEDV cell culture media mixed with PEDV-negative feces to create a fecal slurry. Each treatment had 5 replicates. After 30 minutes of air-drying, treatments were applied, foot traffic was simulated between the trailer and farm site surfaces, samples were collected for quantitative polymerase chain reaction (qPCR) analysis, and 2 PEDV-naïve pigs per replicate were tested via bioassay to assess virus transmission. Results: Pretreatment swabs confirmed high PEDV levels (approximately 9.5 × 106 genomic copies/mL). Post treatment, mean PEDV genomic copies per milliliter at the farm site were 6,148,127 for PC; 94,417 for SB; 10,517 for VHD; and 68 for PWD. Disease transmission was detected via bioassay in all PC replicates and 4 of 5 SB replicates, but not in the VHD, PWD, or NC treatment groups. Implications: Cleaning and disinfecting trailers leaving terminal points of concentration using either water-based methods (VHD or PWD) appear to be practical management strategies for substantively reducing the risk of inter-premises PEDV transmission associated with market pig transport.
Magnesium (Mg) toxicosis in swine is not commonly reported, but the most frequent cause is excess Mg concentration in the feed. The most significant clinical presentation includes diarrhea and caustic cutaneous injury associated with skin contact with urine and feces. Postmortem findings include mild to severe dermatitis and possible gastrointestinal inflammation. Blood chemistry can be used to evaluate electrolyte levels if serum samples are obtained within 48 hours of exposure. However, this is not always feasible and Mg elevations within serum might not be detectable. Collection of suspect feed samples should therefore be prioritized for definitive diagnosis.
A mobile trailer system using nitrogen gas hypoxia for pig depopulation was developed and tested. The system included an 11,360-L liquid nitrogen tank and vaporizer. Oxygen levels dropped from 10% to 2% in < 180 seconds and were maintained at < 2%. Handlers loaded pigs into the trailer. Carcasses were unloaded using a conveyor belt. Trials were conducted in summer and winter conditions with weanlings, grower-finishers, and sows. Cameras inside the trailer allowed observers to note no escape behavior or gasping breathing prior to loss of posture. The operation cycle from filling until unloading the trailer was within 30 minutes.
Objective: Evaluate associations between late-gestation hemoglobin (Hb) and sow removal in commercial swine herds. Materials and methods: Sows (n = 1945; parities 0-8) from 4 US commercial herds were tested for blood Hb on day 100 +/- 12 of gestation. Females were classified as non-anemic (Hb >= 10 g/dL; n = 792) or anemic (Hb < 10 g/dL; n = 1153). At blood sampling, caliper score was recorded for each sow (Knauer Sow Caliper, v2). Reproductive performance data were extracted from production records and sow removals (deaths, euthanasia, or non-age-related culls) were tracked for 70 days post Hb testing. Results: Mean anemia prevalence was 59.3% (range: 46.3%-60.7%) across farms. Prevalence increased with parity, from 40.6% in parity 0 to 82.7% in parity 3 (P <.001). Anemic sows had lower caliper score than non-anemic sows (12.5 vs 13.1; P <.001), with Hb positively correlated to caliper score (r = 0.21; P <.001). Anemic sows had more total piglets born (16.4 vs 15.7; P <.001), but a higher stillborn rate than non-anemic sows (5.3% vs 4.2%; P =.01). No difference in piglets weaned was observed. Removal rates were higher among anemic sows than non-anemic sows (8.4% vs 3.5%; P <.001). Each 1 g/dL increase in Hb was associated with a 43% reduction in removal risk (hazard risk = 0.57; P <.001). Implications: Late-gestation anemia is prevalent in prolific sows and associated with early removal, highlighting the importance of iron status.
The present study evaluated the use of high levels of selected trace minerals and vitamins with antioxidant properties to alleviate the peri-ovulatory oxidative burst in sows and improve within-litter homogeneity. Seventy four Yorkshire-Landrace multiparous sows were used in a completely randomized arrangement with two dietary treatments: CTR: regular gestation diet or; TRT: regular gestation diet supplemented with supranutritional levels of copper, manganese, selenium, vitamins A, E, B6, and C (Table 1). Blood samples were collected eight days before the predicted oestrus (d13), the day after the onset of oestrus (d21), and five days later (d26) for the determination of plasma concentrations of retinol, pyridoxal-5-phosphate, copper, and selenium as well as protein carbonyl and 8-hydroxyguanosine (markers of oxidative stress) and the activity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, and catalase in plasma. Sows reproductive performance (body weight, backfat depth, litter size, stillbirth, piglets birthweight, litter homogeneity) was assessed. Plasma selenium and pyridoxal-5-phosphate concentrations were similar between treatments at d13, increased significantly for TRT at d21 and decreased to CTR levels by d26 (P ≤ 0.01). No effect of treatment was detected on plasma retinol and copper concentrations (P ≥ 0.61). No effect of treatment was detected on plasma superoxide dismutase and catalase activities (P ≥ 0.52). Although not statistically different (P = 0.11), glutathione peroxidase activity increased almost 10 % from d21 to d26 in TRT sows compared to less than 3 % in the CTR group. No effect of treatment was detected on plasma protein carbonyl and 8-hydroxyguanosine concentrations (P ≥ 0.23). However, time effects were detected. Plasma copper concentrations were not different between d13 and d21 but decreased at d26 (P = 0.06) whereas plasma retinol concentrations were lowest at d13 and did not differ between d21 and d26 (P = 0.03). Plasma superoxide dismutase activity was lowest at d13, highest at d21, intermediary at d26 (P < 0.01) whereas plasma glutathione peroxidase activity was lowest at d21 and did not differ between d13 and d26 (P < 0.01) and plasma catalase activity was not different between d13 and d21 but increased at d26 (P = 0.04). Plasma protein carbonyl concentrations was highest at d13 and did not differ between d21 and d26 (P < 0.01). Plasma 8-hydroxyguanosine concentrations were not different between d13 and d21 but decreased at d26 (P = 0.01). No effect of treatment was detected on sows reproductive performance (P ≥ 0.17). In conclusion, although supplementation of trace minerals and vitamins with antioxidant properties at high dietary levels enhanced the plasma concentration of some of these nutrients, it had little impact on the modulation of the antioxidant system during the peri-ovulatory period, which apparently did not induce systemic oxidative stress multiparous sows.
Objectives: Establish blood reference values and evaluate the influence of age on the hematological profile of indigenous Slovenian Ktikopolje pigs and compare these values with conventionally farmed pigs. Materials and methods: Blood samples were taken from 57 grower and 36 finisher Kigkopolje pigs from 2 organic farms and 183 grower and 47 finisher pigs from 6 conventional farms in Slovenia. Samples were analyzed using an automatic hematology analyzer to measure white blood cell count, red blood cell count (RBC), hematocrit (Hct), hemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and platelet count (PLT). Results: The hematological parameter reference values of the Krgkopolje pig breed corresponded with reference ranges in the literature. Pig age had a significant effect on hematologic parameters. Organic grower pigs had significantly higher RBC and MCHC values and lower Hct, MCV, and MCH values than conventional pigs. Organic finisher pigs had significantly higher PLT values and lower Hb, Hct, MCV, and MCH values than conventional pigs. All reported differences in hematologic values between KrAkopolje and conventional pigs are not expected to affect clinical outcomes. Implications: These hematologic reference values can be used as a diagnostic tool for assessing the health status of Krikopolje pigs, but pig age must be accounted for. Reference values from the literature are suitable for assessing the health status of both conventionally and organically reared pigs.
Ergot alkaloids (EA) are produced by fungi, including Claviceps purpurea, which can lead to EA contamination of wheat and cereal grains and cause sow agalactia by inhibiting prolactin production. In this case of sow agalactia and increased piglet mortality, a diagnosis of ergotism was made based on clinical signs and feed analysis. The lactation diet had EA at 330 ppb and was fed to sows for 12 to 14 days resulting in 79% (50%) mean (SD) mortality in exposed litters. Ergot alkaloid levels as low as 0.33 mg/kg of feed (0.33 ppm) may result in clinical signs in lactating sows.
Infection with porcine reproductive and respiratory syndrome virus (PRRSV) in breeding herds causes significant changes in key production indicators (KPIs). Still, the swine industry lacks a clinical case definition for PRRSV outbreaks based on KPIs, hindering early detection and outbreak characterization. This study analyzed data from 75 outbreaks resulting in a definition based on KPI signals and diagnostic insights. An Excel tool for decision makers was created avoiding complex statistical methods. Using a 15 -week moving average and a 2 SD threshold minimized false negatives and false positives, enabling proactive management and early outbreak detection through a reliable, accessible framework.
Tonsil-oral-scrubbing (TOSc) can retrieve fluids from the sow's oropharyngeal and tonsillar area without snaring and shows comparable porcine reproductive and respiratory syndrome virus RNA detection rates to tonsil scrapings. This descriptive study used an endoscope-like cable with light to visualize the collection process and histopathology to characterize TOSc sample composition. Video showed that the soft palatine tonsils were reached after the TOSc collector passed the hard palate. Histopathology revealed the presence of squamous mucosal cells and small clusters of immune "cells in TOSc samples. This study will help train farm staff and veterinarians on proper TOSc sample collection from sows.
Objective: Evaluate the impact of Lactobacillus salivarius (Ligilactobacillus salivarius comb nov) DSPV014C supplementation on weaned piglet growth performance through its effect on the modulation of microbiota and intestinal morphology. Materials and methods: In a randomized complete block design, 20 piglets were divided into two groups, probiotic group (PG) supplemented with L salivarius DSPV014C and control group (CG) without supplementation, at 28 days of age and kept under study for 42 days. Feces were sampled weekly to evaluate microbial population dynamic and diversity, evenness, and richness indexes.To calculate average daily gain, average daily feed intake, and feed conversion ratio (FCR), piglets were weighed and feed consumption was registered weekly. Three piglets from each group were euthanized on day 42 and samples of the small intestine taken to evaluate intestinal morphology through villi length, crypt depth, and the ratio of the two (V/C). Results: Lactobacillus salivarius was recovered in feces from PG on day 7 demonstrating its ability to reach the intestine. Microbiota modulation differed resulting in different profiles between groups; PG exhibited higher diversity (P =.01) and richness (P =.07) indexes, while no differences were observed for evenness. The PG showed lower FCR and longer villi length and higher V/C ratio than CG (P <.05). Implications: The FCR improved in PG compared to CG piglets, which could be explained by an increase in the digestion and absorption capacity due to longer intestinal villi and differential modulation of the intestinal microbiota with higher richness and diversity indexes.
Objective: Evaluate the effects of a novel oral drench suspension formulation of meloxicam on sow body temperature within 24 hours post farrowing, piglet survivability, and piglet growth. Materials and methods: A total of 837 sows in a commercial farm were randomly assigned to either receive a single, 90-mg dose (6 mL of a 1.5% suspension) of meloxicam via oral drench upon completion of farrowing (MEL; n = 419) or no treatment post farrowing (CON; n = 418). Rectal temperatures were recorded at the end of farrowing, and 12 and 24 hours post farrowing. Farm protocol required sows with a rectal temperature 39.67 C to receive flunixin and ampicillin for 3 days (FA; n = 243). Litter size and weight were recorded on day 0 and before weaning, with daily tracking of piglet mortality and causes. Results: Meloxicam reduced sow rectal temperatures by 0.08 C in the first 12 hours post farrowing (P =.03). Additionally, MEL+FA sows (n = 119) tended to have lower rectal temperatures by 0.15 C in the first 12 hours after farrowing (P =.09). Treating parity 1 sows with MEL reduced preweaning diarrhea in piglets compared to CON (18.5% vs 33.8%,respectively; P <.01). Meloxicam did not significantly impact preweaning mortality or piglet growth performance. Implications: This study exhibited the ability of a single dose of meloxicam administered to the sow at farrowing to reduce fever within the first 12 hours of dosing and its potential to reduce the incidence of preweaning diarrhea in nursing piglets.
Objective: This study aimed to analyze the serological dynamics of Lawsonia intracellularis under field conditions in intensive swine production systems in Chile. Materials and methods: Between 2013 and 2018, 80 serological profiles were collected from 23 intensive central-Chilean swine farms, containing 3257 serum samples from different animals. A cross-sectional study design with multiple sampling points was used and samples were classified into commercial pigs, growing gilts, or breeding sows. Herds were classified as single or multisite. Samples were collected after weaning in a 3- to 4-week interval. Samples were analyzed for the presence of anti-L intracellularis antibodies using a commercial enzyme-linked immunosorbent assay. Results: Of the 3257 serum samples analyzed, 56.62% were positive and 15.94% were suspect for L intracellularis. Higher seropositivity was observed in breeding sows and commercial pigs, with the lowest seropositivity in growing gilts (P < .05). In commercial pigs, the highest seropositivity was observed in ages closer to market with statistical differences between production systems at specific age ranges. For growing gilts, we observed a constant increase in seropositivity without evidence of maternal immunity decline. Breeding sows had the highest seropositivity, with parity 6 or more having the highest percentage of inhibition, even though there were differences among parity groups.
A Mycoplasma hyopneumoniae elimination program was undertaken on a 1200-sow farm. While the exact duration is not known, it is estimated that despite an extended closure and treatments with different antibiotics, some sow tracheobronchial swabs remained M hyopneumoniae positive for at least 365 days.
This paper reports the occurrence of swine rabies in Brazil and discusses the difficulties of clinical and laboratory diagnosis in this species. Two pigs from different farms, were diagnosed with rabies and were raised where cattle had previously died from the disease. Affected pigs had hindlimb paralysis, lateral recumbency, and paddling movements. Histological examination of the brain revealed lymphoplasmacytic encephalitis, although intracytoplasmic inclusions were lacking. Immunohistochemistry revealed intense staining of rabies antigen in brainstem neurons, moderate immunoreactivity was observed in the cerebrum, and was absent in the cerebellum. Immunohistochemistry was effective in the definitive diagnosis of rabies encephalitis in swine.
Two naive sow herds became infected with porcine reproductive and respiratory syndrome virus (PRRSV) and were exposed by live virus inoculation (LVI) on week 0. Serum and tonsil scrapings were collected on week 20 post LVI and tested for PRRSV by reverse-transcriptase polymerase chain reaction (RT-PCR). For either sample type, non-negative animals were considered infected. Prolonged infection rate was 3.56% in herd 1 and 1.76% in herd 2. Age and breed were significant factors of prolonged infection. Twenty of thirty-five infected animals removed from herd 2 and resampled on week 27 were still PRRSV positive using RT-PCR on tonsil scrapings.
The HemoCue 201 was used to compare hemoglobin (HbC) across blood sampling sites. Tail docking samples had lower HbC than both ear and mammary vein samples (P = .001). Both point-of-care and laboratory HbC testing methods showed agreement, with biases of 0.2 g/dL (ear) and -0.45 g/dL (jugular).
Objective: Investigate the influence of influenza A(H1N1)pdm09 virus (pH1N1v) on feed conversion efficiency (FCE) in Norwegian Landrace and Duroc pigs. Materials and methods: This observational study analyzed the growth and serological data of 1954 grower pigs collected from 43 nucleus breeding herds in eastern Norway between 2009 and 2012. Serial serological tests, enzyme-linked immunosorbent assay, and hemagglutination inhibition were used to detect pH1Nlv antibodies in pigs weighing 100 kg. Statistical analyses included mixed-effects regression modelling, Cox regression, and Kaplan-Meier Failure analysis to assess the effects of breed on pH1Nlv influence on growth performance. Results: Duroc pigs experienced a greater reduction in FCE (5.6%; 95% CI, 5.5%-5.7%) compared to Landrace pigs (3.5%; 95% CI, 1.3%-5.6%) when exposed to pH1N1v. Seropositive pigs of both breeds maintained normal growth rates under ad libitum feeding conditions. To reach 100 kg body weight, seropositive Landrace pigs consumed 2.4 kg (95% CI, 0.9-3.9 kg) more feed, while Duroc pigs consumed 3.8 kg (95% CI, 3.7-4.0 kg) more feed than their seronegative counterparts. Implications: Results suggest breed-specific differences in resilience to influenza even though the overall appetite of seropositive pigs was unimpaired during the growth phase (approximately 33-100 kg body weight). Study findings highlight the economic implications of selecting appropriate breeds for specific environmental challenges. However, the study's observational nature limits the ability to infer causality and may not be generalized to other breeds or crossbreeds. By understanding breed-specific responses to influenza, producers can optimize breed selection strategies to enhance overall herd resilience and efficiency, contributing to more sustainable pork production.
Porcine reproductive and respiratory syndrome (PRRS) continues to represent a significant cost to the swine industry and efforts are focused on prevention and mitigation of losses across production phases. Herein describes a PRRS modified -live virus (MLV) vaccinated breeding herd that changed commercial MLV vaccines to improve post-weaning performance. Two whole -herd vaccinations with a new PRRS MLV vaccine, administered 4 weeks apart, occurred without breeding herd production disruptions and with limited changes in diagnostic results. Replacement gilts tested PRRS virus negative 10 weeks post vaccination with the new MLV vaccine. Diagnostics were intermittently positive in the breeding herd and early nursery.
Objective: To conduct a pilot study, under noncommercial conditions, to assess the potential efficacy of ivermectin administered subcutaneously to pigs following a porcine reproductive and respiratory syndrome virus (PRRSV) 1-4-4 L1C challenge. Materials and methods: A total of 50 feeder pigs were enrolled and allocated into 2 groups. On day 0, all pigs were challenged with PRRSV 1-4-4 L1C. Animals in group 1 received an ivermectin dose of approximately 500 µg/kg administered subcutaneously at 1 and 3 days post challenge (DPC). Group 2 animals remained untreated. Serum was collected from each animal on DPC 1, 3, 5, 7, 10, and 14 and tested individually to assess PRRSV viremia levels via quantitative polymerase chain reaction (qPCR). On DPC 14, pigs were weighed, euthanized, necropsied, and lungs were scored for lung lesions. Bronchoalveolar lavage (BAL) was performed on each set of lungs and the corresponding level of viremia was measured via qPCR. Any animal that died prior to necropsy was weighed, received a lung score, and BAL collected. Results: There was no significant difference in viremia levels between treatment groups. There was a trend toward significance between treatment groups in lung lesion scores with the ivermectin-treated pigs exhibiting less lung pathology compared to the control group (P = .05). Implications: Ivermectin administered to pigs post virulent PRRS 1-4-4 L1C challenge did not reduce the level of viremia in serum or BAL fluid but may have reduced lung lesions.
