Concentration of pollutant levels in the finisher barn were distinctly higher during winter than during summer.
Use of a wet feed system reduced respirable endotoxin concentrations substantially.
Evolving production practices in the swine industry may alter the working environment. The second part of this research project characterized the wet versus dry feed in finishing on air contaminant concentrations.
Eight-hour time-weighted ammonia, hydrogen sulfide, respirable dust, respirable endotoxin, and carbon dioxide concentrations and temperature were measured regularly at stationary locations throughout a year in a facility with parallel finishing rooms using dry and wet feed delivery systems.
All ammonia, respirable dust, and carbon dioxide concentrations were below relevant regulatory and recommended levels . Hydrogen sulfide concentrations were always below the regulatory levels but they reached one of the recommended threshold levels on two occasions in the dry feed room. Respirable endotoxin concentrations regularly exceeded the proposed health-based recommended occupational exposure limit during autumn in the dry feed room and in both rooms during winter.
In all cases, concentrations varied significantly as a function of time. Concentrations of respirable dust, endotoxin and carbon dioxide were distinctly higher during winter than during summer. Temperatures varied significantly with time, but this difference was driven more by the need of the growing piglets than by seasonal differences.
Use of a wet feed system reduced respirable endotoxin concentrations substantially. Changing ventilation rates in response to seasonal differences influenced contaminant concentrations more than feed type.
Pollutant levels increased as ventilation rates decreased during the cold months.
Pen housing lead to higher levels of NH3, respirable dust, and endotoxin when compared to stalls.
Evolving production practices in the swine industry may alter the working environment. This research project characterized the influence of stall versus pen gestation housing on air contaminant concentrations.
Eight-hour time-weighted ammonia, hydrogen sulfide, respirable dust, respirable endotoxin, and carbon dioxide concentrations and temperature were measured
regularly at stationary locations throughout a year in a facility with parallel gestation stall and open pen housing. Hazard indices were calculated using ammonia,
hydrogen sulfide, and endotoxin concentrations and relevant occupational exposure limits.
Due to reductions in ventilation rates as outdoor temperatures decreased, season affected pollutant levels more than other factors. Concentrations were greater during the
winter than summer (Figure 1). Ammonia, dust, and endotoxin were 25%, 43%, and 67% higher, respectively, on average, in the room with gestation pens than in the room with stalls. While individual contaminant concentrations were generally below regulatory limits, hazard index calculations suggest that the effects of combined exposures on respiratory health may pose a risk to farm workers. Additionally, elevated levels of respirable endotoxin and hydrogen sulfide were detected during power washing.
Ventilation changes in response to seasonal requirements influenced air contaminant concentrations more than production practices, especially housing type.
Cumulative incidence of PED and PDCoV in Canada is decreasing according to data coming from the industry for the year 2014, 2015 and 2016.
PED showed a cyclical pattern when looking at the number of farms infected. However, PDCoV showed a more erratic pattern with no clear trends.
Industry driven disease control programs provide useful information to understand temporal evolution and disease patterns.
The primary goal of this study was to estimate herd-level incidence and prevalence measures for PEDV and PDCoV in swine herds in Ontario (Canada) between January 2014 and December 2016, based on industry data (Ontario Swine Health Advisory Board (OSHAB) Disease Control Program (DCP)).
The full paper was published in the Transboundary and Emerging Diseases journal.
Herd-level incidence risk and rate of two novel porcine coronaviruses (PEDV and PDCoV) in Ontario swine herds between 2014 and 2016, and estimated prevalence of positive cases at the end of each year based on data provided in the Ontario Swine Health Advisory Board (OSHAB) Disease Control Program (DCP) database (average number of herds for 2014–2016 = 1093).
PED showed a cyclical pattern over the three years of the study while PDCoV showed a more erratic pattern. Incidence decreased over time between 2014 and 2016 in both, PED and PDCoV.
Porcine Deltacoronavirus (PDCoV) was first reported in the US in 2014.
Monitoring of PDCoV cases showed that it is still present in pig herds from the United States.
PDCoV testing and reporting must continue in order to increase our understanding of the disease.
Porcine Deltacoronavirus (PDCoV) was first detected in the US in 2014. The complete genome of a United States’ PDCoV isolate was characterized by Marthaler et al. (2014), which was ~99% similar to a virus detected in Hong Kong.
Clinical signs may be similar to Porcine Epidemic Diarrhea (PED) and Transmissible gastroenteritis coronavirus (TGEV), including acute diarrhea, mild to moderate vomiting, and ultimately death especially in neonatal pigs.
PDCoV continues to be present in the United States swine herd. Since March, 2017 PDCoV cases have been passively reported to MSHMP. Over this period of time, 37 cases have been reported by six participant systems.
Since November 2017, 24 PDCoV cases were communicated to MSHMP, representing 67% of the reported cases.
PDCoV still occurs in the US at an apparent low number of reported cases. Swine producers and veterinarians must stay vigilant for clinical signs compatible with PDCoV and continue to test for this pathogen.
Even though small differences between both EWMAs exist, the EWMA of the original 13 participating systems is still a good indicator of the overall PRRS EWMA.
Questions from participants are always welcome and help us to provide answers and insights to all of you.
REMINDER: WHAT IS THE EWMA?
The Exponential Weighted Moving Average (EMWA) is a statistical method that averages data over time, continually decreasing the weight of data as it moves further back in time. An EWMA chart is particularly good at monitoring processes that drift over time and is used to detect small shifts in a trend.
In our project, EWMA is used to follow the evolution of the % of farms at risk that broke with PRRSV every week. EWMA incorporates all the weekly percentages recorded since the beginning of the project and gives less and less weight to the results as they are more removed in time. Therefore, the % of farms at risk that broke with PRRSV last week will have much more influence on the EMWA than the % of farms at risk that broke with PRRSV during the same week last year.
Results from this year’s comparison
EWMA 13 is still a good representation of the overall EWMA. The reason that the EWMA 13 is still representative may be because they cover a wide area of the States and they still represent a high percentage of the final EWMA. A minor difference occurred in 2017’s summer as some farms of the 13 experienced outbreaks. However, as we have discussed in previous science pages each state or region seems to have a different EWMA pattern.
Many swine producers have been looking for an alternative to tail docking since it is a painful procedure for pigs.
A study examining welfare and performance of pigs with docked and undocked tails was performed
Performance was unaffected by tail docking, and it reduced incidence of tail damage
A study was conducted to evaluate the effect of tail docking on welfare and performance of growing-finishing pigs. Pigs, including 120 pigs that were tail-docked at birth and 120 pigs that remained with intact tails were used. Pigs were housed in 8 pens of 30 pigs in a
confinement barn for 16 weeks, with 4 pens each housing pigs of both sexes with docked or intact tails.
Results indicate that tail docking did not affect daily gain, feed intake, gain to feed ratio. During the study period, 5% of docked pigs were removed from their home pen due to tail damage, compared to 21% of intact pigs were removed for reasons associated with tail biting or tail damage. Consequently, 97% of docked pigs and 90% of intact pigs were sold for full value.
This study suggests that tail docking did not affect growth performance of pigs or eliminate occurrence of tail biting, but it reduced the incidence of
tail damage in pigs housed in a confinement system.