Porcine Health Manag

. 2021 Feb 26;7(1):21.

 doi: 10.1186/s40813-021-00203-4.

Effect of PRRSV stability on productive parameters in breeding herds of a swine large integrated group in Spain

D Torrents 1 2, J Miranda 3, P C Gauger 4, A Ramirez 4, Dcl Linhares 4

Affiliations 

• PMID: 33637120
 
• DOI: 10.1186/s40813-021-00203-4

Free article

Abstract

Background: In breeding herds, porcine reproductive and respiratory syndrome (PRRS) clinically manifests as increased abortions, number of stillbirths, and pre-weaning mortality, and as a direct consequence, results in a decrease of the number of piglets weaned per sow per year. Breeding farm classification according the PRRS virus (PRRSV) status (unstable or stable) is a key control strategy for this disease. The aim of this study was to evaluate the production improvement related to achieving a PRRSV stable status in breeding herds in Spain. For this purpose, epidemiological and productivity data were collected from a systematic PRRSV monitoring program in 35 breeding herds from a large integrated swine group in Spain. A comparative statistical analysis was conducted using four key production indicators (KPI) between different PRRSV status and a generalized linear mixed model: weekly abortions/1000 sows (ABTHS), born-alive rate (BAR), pre-weaning mortality rate (PWMR), and number of weaned piglets per 1000 sows (WPTHS).

Results: From the 35 monitored farms during a total period of 58 weeks, we collected 49 to 58 weeks of production data and PRRSV classification status for each study farm. This represented a total of 1997 (741 unstable and 1256 stable) weekly data collected that was eligible for the KPI comparative study. PRRSV stability was associated with significant improvement in BAR (+ 1.10 %, p < 0.001), PWMR (-0.88 %, p < 0.002) and WPTHS (+ 24.52, p < 0.0001).

Conclusions: These results demonstrate for the first time the improved production due to achieving PRRSV stability in breeding herds under field conditions in a European country. Increased number of born-alive piglets and a reduction of piglet pre-weaning mortality represents an increase of 1.28 weaned piglets per sow per year if PRRSV stability was achieved and maintained for one-year period in a breeding farm.

Keywords: Farm classification; Monitoring; Production parameters; Sows; Weaned piglets.

Antibody responses to PRRSv, IAV, and M. hyopneumoniae from weaning to the end of the finisher stage in fourteen groups of pigs in Ontario

 BMC Vet Res

. 2021 Feb 17;17(1):82.

 doi: 10.1186/s12917-021-02756-6.

Antibody responses to porcine reproductive and respiratory syndrome virus, influenza A virus, and Mycoplasma hyopneumoniae from weaning to the end of the finisher stage in fourteen groups of pigs in Ontario, Canada

Elana Raaphorst 1, Abdolvahab Farzan 2 3, Robert M Friendship 4, Brandon N Lillie 1

Affiliations 

• PMID: 33596907
 
• DOI: 10.1186/s12917-021-02756-6

Abstract

Background: Respiratory diseases are among the most important factors affecting swine farm productivity in Canada. The objectives of this study were to investigate antibody responses to porcine reproductive and respiratory syndrome virus (PRRSV), influenza A virus (IAV), and Mycoplasma hyopneumoniae (M. hyopneumoniae) from weaning to the end of the finisher stage on a subset of commercial swine farms in Ontario, Canada, and to examine the association between nursery diet and antibody responses.

Results: Overall, older pigs were more likely to test seropositive for PRRSV and less likely to test seropositive for M. hyopneumoniae (p < 0.001). Pigs were more likely to test seropositive for IAV at weaning and the end of the grower and finisher stages compared to the end of nursery (p < 0.001). Pigs that were seropositive for IAV were more likely to test seropositive for both PRRSV and M. hyopneumoniae (p < 0.001). Two, 9, and 4 groups that had more than 20% of pigs seropositive to PRRSV, IAV, and M. hyopneumoniae, respectively, from the end of nursery to the end of finisher were classified as seropositive. Pigs fed a plant-based (low complexity) diet during nursery were more likely to be seropositive for PRRSV (p < 0.001) but there were no significant differences in seropositivity to IAV or M. hyopneumoniae due to nursery diet complexity.

Conclusions: This study provides information regarding changes in serum antibody in pigs across different stages of production and highlights periods of vulnerability. Additionally, these findings may encourage further research into the effects of nursery diet complexity on disease susceptibility and immune response.

Keywords: Antibody response; ELISA; Influenza A virus; Mycoplasma hyopneumoniae; Nursery diet; Porcine reproductive and respiratory syndrome; swine.

 Prev Vet Med

. 2021 Jan 27;189:105270.

 doi: 10.1016/j.prevetmed.2021.105270.Online ahead of print.

Association of wild-type PRRSV detection patterns with mortality of MLV-vaccinated growing pig groups

Cesar A A Moura 1, Reid Philips 2, Gustavo S Silva 1, Alejandro Ramirez 1, Phillip C Gauger 1, Derald J Holtkamp 1, Daniel C L Linhares 3

Affiliations 

• PMID: 33550121
 
• DOI: 10.1016/j.prevetmed.2021.105270

Abstract

PRRS is a viral disease characterized by increasing reproduction losses in breeding herds and worsening performance of growing pigs, which leads to a considerable economic impact. A better understanding of the differences in the infection patterns of the virus in growing pig batches would help to develop cost-effective surveillance methods and disease control and elimination programs. Therefore, field studies documenting growing pig productivity according to the patterns of wild-type-PRRSV (wt-PRRSV) detection in the field are needed. This study was conducted with the objectives to (1) characterize patterns of wt-PRRSV-1 and wt-PRRSV-2 RNA detection over time in modified-live virus (MLV)-vaccinated batches of growing pigs raised in pig-dense regions of the USA; (2) compare wean-to-finish mortality among batches of growing pigs characterized with the different patterns of wt-PRRSV-1 and wt-PRRSV-2 detection; and (3) compare wean-to-finish mortality among batches of growing pigs characterized with the different patterns of wt-PRRSV-2 detection and vaccinated with two different doses of PRRS MLV vaccine. Eighty-one batches of growing pigs were originated from PRRSV positive-stable and unstable sow farms and vaccinated with two different doses of PRRS MLV vaccine. All batches were monitored for wt-PRRSV by testing six oral fluids every three weeks from weaning to marketing. Diagnostics were conducted to detect wt-PRRSV-1 and wt-PRRSV-2 by RT-qPCR testing and ORF-5 region sequencing. K-means clustering analysis was applied to identify batches sharing similar patterns of wt-PRRSV detection over time. Regression analyses were used to compare mortality among batches of growing pigs characterized with different patterns of wt-PRRSV detection over time. Thirty-eight percent of batches were detected with wt-PRRSV-1 during the growth phase, with three different patterns of detection. Detection of wt-PRRSV-1 was not associated with significant increase on mortality. Ninety-one percent of batches were detected with wt-PRRSV-2 during the growth phase, with four different patterns of detection. Batches originated from PRRSV positive-unstable farms had highest mortality rate (p < 0.0001) and were characterized as Unstable wt-PRRSV-2 detection pattern. Batches characterized with Early wt-PRRSV-2 detection pattern had higher mortality than batches characterized by Mid, Late and No wt-PRRSV-2 detection during the growth phase (p < 0.0001). Batches with Mid wt-PRRSV-2 detection had higher mortality than batches characterized with Late wt-PRRSV-2 detection (p < 0.0124). Mortality rate of batches characterized with Unstable and Early wt-PRRSV-2 detection patterns was lower when pigs were vaccinated with two doses of PRRS MLV vaccine, compared to batches that received only one dose. Results presented in this study suggested that early wt-PRRSV exposure on pig populations was associated with higher wean-to-finish mortality. Additionally, results suggested that vaccination with two PRRS MLV doses was associated with lower mortality rate, when growing pig populations had early wt-PRRSV exposure.

Keywords: Field epidemiology; Growing pigs; Mortality; PRRSV; Swine.

Copyright © 2021 Elsevier B.V. All rights reserved.

Survival of PRRSV and PEDV in compost formed from preprocessed carcasses

 Transbound Emerg Dis

Survival of swine pathogens in compost formed from preprocessed carcasses

Brent Pepin 1, Todd Williams 1, Dale Polson 2, Phillip Gauger 3, Scott Dee 1

 doi: 10.1111/tbed.13876.

Abstract

An introduction of a Foreign Animal Disease (FAD) like African Swine Fever Virus (ASF) would be financially devastating. For example, ASF, a highly contagious pathogen with high mortality rates, is a World Health Organization reportable disease that has recently been spreading across Asia and Europe. Control of ASF would likely require mass euthanasia of infected and exposed animals similar to the United Kingdom's elimination of Foot and Mouth Disease (FMD). Subsequent disposal of infectious carcasses must adequately eliminate the virus and prevent further transmission of the disease. Although composting swine carcasses is widely used throughout the industry, limited data is available describing pathogen survival or elimination during this process. While current methods have evaluated the composting of swine carcasses under temperature-controlled settings, they have not considered the effects of adverse weather conditions (e.g., cold winter conditions) where composting is routinely performed. This study utilized preprocessing (grinding) of swine carcasses prior to composting, which decreases the amount of required carbon material and land space. The ability of composting to reduce the level of viral nucleic acid during cold weather conditions and the risk of environmental contamination that may occur during preprocessing was evaluated. In this study, pigs challenged with Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) and Porcine Epidemic Diarrhea Virus (PEDV), common domestic diseases, before euthanasia provided infectious carcasses containing pathogen surrogates. Composting of preprocessed carcasses achieved adequate temperatures necessary to eliminate FAD and common swine pathogens during cold weather conditions (monitored by compost temperature over time, virus diagnostic testing, and swine bioassay for PRRSV and PEDV). Under the conditions of this study, composting preprocessed carcasses presents minimal risk to air and groundwater contamination. In conclusion, composting preprocessed euthanized swine under adverse weather conditions is a safe and feasible option for mass disposal of infected carcasses.

Keywords: Compost; Grinding; PEDV; PRRSV; Pathogen; Pre-processing.

This article is protected by copyright. All rights reserved.

Spatial relative risk and factors associated with PRRS outbreaks in US breeding herds

 Prev Vet Med

. 2020 Sep 1;183:105128.

 doi: 10.1016/j.prevetmed.2020.105128. Online ahead of print.

Spatial relative risk and factors associated with porcine reproductive and respiratory syndrome outbreaks in United States breeding herds

Juan M Sanhueza 1, Mark A Stevenson 2, Carles Vilalta 3, Mariana Kikuti 4, Cesar A Corzo 4

• PMID: 32937200
 
• DOI: 10.1016/j.prevetmed.2020.105128

Abstract

Details of incident cases of porcine reproductive and respiratory syndrome (PRRS) in United States breeding herds were obtained from the Morrison's Swine Health Monitoring Project. Herds were classified as cases if they reported an outbreak in a given season of the year and non-cases if they reported it in a season other than the case season or if they did not report a PRRS outbreak in any season. The geographic distribution of cases and non-cases was compared in each season of the year. The density of farms that had a PRRS outbreak during summer was higher in Southern Minnesota and Northwest-central Iowa compared to the density of the underlying population of non-case farms. This does not mean that PRRS outbreaks are more frequent during summer in absolute terms, but that there was a geographical clustering of herds breaking during summer in this area. Similar findings were observed in autumn. In addition, the density of farms reporting spring outbreaks was higher in the Southeast of the United States compared to that of the underlying population of non-case farms. A similar geographical clustering of PRRS outbreaks was observed during winter in the Southeast of the United States. Multivariable analyses, adjusting for the effect of known confounders, showed that the incidence rate of PRRS was significantly lower during winter and autumn during the porcine epidemic diarrhea (PED) epidemic years (2013-2014), compared to PRRS incidence rates observed during the winter and autumn of PED pre-epidemic years (2009-2012). After 2014, an increase in the incidence rate of PRRS was observed during winter and spring but not during autumn or summer. Pig dense areas were associated with a higher incidence rate throughout the year. However, this association tended to be stronger during the summer. Additionally, herds with ≥2500 sows had an increased incidence rate during all seasons except spring compared to those with <2500 sows. PRRS incidence was lower in year-round air-filtered herds compared to non-filtered herds throughout the year. We showed that not only the spatial risk of PRRS varies regionally according to the season of the year, but also that the effect of swine density, herd size and air filtering on PRRS incidence may also vary according to the season of the year. Further studies should investigate regional and seasonal drivers of disease. Breeding herds should maintain high biosecurity standards throughout the year.

Keywords: Factors; Incidence; PRRS; Risk; Sow; Spatial.

Copyright © 2020 Elsevier B.V. All rights reserved.

Feasibility of oral fluid collection from pre-weaning piglets

. 2020 Feb 13;9:100099.

 doi: 10.1016/j.vas.2020.100099. eCollection 2020 Jun.

Feasibility of pooled oral fluid collection from pre-weaning piglets using cotton ropes

Gwenaël Boulbria 1, Valérie Normand 1, Mily Leblanc-Maridor 2, Catherine Belloc 2, Pauline Berton 1, Franck Bouchet 1, Arnaud Lebret 1

Affiliations

• 1Porc.Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France.
• 2BIOEPAR, INRA, Oniris, Université Bretagne Loire, 44307 Nantes, France.

• PMID: 32734109
 
• PMCID: PMC7386738
 
• DOI: 10.1016/j.vas.2020.100099

Free PMC article

Abstract

Collection of pooled oral fluid (OF) by allowing pigs to chew on a cotton rope is an alternative to blood sampling. However, little is known about the applicability of this method to suckling piglets. The objectives of the present study were to describe the spontaneous interaction of suckling piglets with a rope and to investigate the influence of a rope pre-exposure on the success rate of sampling. We studied the interaction dynamics of 21 and 28 days-old suckling piglets with a cotton rope presented for 30 min. Ropes were manually wrung out inside plastic bags to release the oral fluid. A total of 49 litters were included. Percentages of success of pooled OF collection for 28-day-old, 21-day-old and 21-day-old pre-exposed litters were 82%, 62% and 100%, respectively. The mean volume collected did not differ between groups. Without pre-exposure, 84.7% and 95% of piglets interacted spontaneously with the rope at 21 and 28 days of age, respectively. The latency between rope presentation and interaction was highly variable between piglets within litters: from < 10 s to 30 min. Among piglets having interacted with the rope, the interaction lasted for at least 60 s for 90% and 91.4% of 21 and 28-day-old piglets, respectively. Pooled OF collection is achievable prior to weaning in piglets of at least 21 days of age. Pooled OF sampling is representative at litter level if collection is successful. In order to improve the success rate of collection, pre-exposing the piglets with a rope one day prior to sampling is effective.

Keywords: Diagnostic; Disease surveillance; Oral fluid; Pig; Suckling piglets.

© 2020 The Author(s).