Science Page: Effects of gestation pens versus stalls and wet versus dry feed on air contaminants in swine production (Part 2)

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, we are sharing the second part of a scientific paper from faculty in the School of Public Health at the University of Minnesota, regarding the effect of gestation pens versus group housing and dry versus wet feed on air contaminants. This week we are sharing the second part of the results, you may read the first half here.

Keypoints:

  • 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.

Objective:

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.

Methods:

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.

Results

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.

wet versus dry feed air quality.jpeg

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.

Conclusions

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.

You can also read the full article on the journal’s website.

Science Page: Effects of gestation pens versus stalls and wet versus dry feed on air contaminants in swine production (Part 1)

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, we are sharing part of a scientific paper from faculty in the School of Public Health at the University of Minnesota, regarding the effect of gestation pens versus group housing and dry versus wet feed on air contaminants. This week we are sharing the first half of the results, join us next week to read the second part.

Keypoints:

  • 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.

Objective

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.

Methods

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.

air contaminant group housing versus stall

Results

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.

Conclusions

Ventilation changes in response to seasonal requirements influenced air contaminant concentrations more than production practices, especially housing type.

You can also read the full article on the journal’s website.