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.
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.