Skip to main content Accessibility help

Production responses of weaned pigs after chronic exposure to airborne dust and ammonia

  • C. M. Wathes (a1), T. G. M. Demmers (a1), N. Teer (a1), R. P. White (a1), L. L. Taylor (a2), V. Bland (a2), P. Jones (a2), D. Armstrong (a3), A. C. J. Gresham (a4), J. Hartung (a5), D. J. Chennells (a6) and S. H. Done (a7)...


Nine hundred and sixty weaned pigs were exposed for 5·5 weeks to controlled concentrations of airborne dust and ammonia in a single, multi-factorial experiment. Production and health responses were measured but only the former are reported here. The treatments were a dust concentration of either 1·2, 2·7, 5·1 or 9·9 mg/m3 (inhalable fraction) and an ammonia concentration of either 0·6, 10·0, 18·8 or 37·0 p. p. m., which are representative of commercial conditions. The experiment was carried out over 2·5 years and pigs were used in eight batches, each comprising five lots of 24 pigs. Each treatment combination was replicated once and an additional control lot (nominally ≈ 0 mg/m3 dust and ≈ 0 p. p. m. ammonia) was included in each batch to provide a baseline. The dust concentration was common across the other four lots in each batch in which all four ammonia concentrations were used; thus the split-plot design was more sensitive to the effects of ammonia than dust.

The pigs were kept separately in five rooms in a purpose-built facility. The pollutants were injected continuously into the air supply. Ammonia was supplied from a pressurized cylinder and its concentration was measured with an NOx chemiluminescent gas analyser after catalytic conversion. The endogenous dust in each room was supplemented by an artificial dust, which was manufactured from food, barley straw and faeces, mixed by weight in the proportions 0·5: 0·1: 0·4. The ingredients were oven-dried, milled and mixed and this artificial dust was then resuspended in the supply air. Dust concentration was monitored continuously with a tribo-electric sensor and measured continually with an aerodynamic particle sizer and gravimetric samplers.

Live weight per pig and cumulative food intake per pen of 12 pigs were measured after 5·5 weeks of exposure. Exposure to both aerial pollutants depressed live weight relative to the control (control v. pollutant, 25·7 v. 25·0 (s.e.d. = 0·33) kg, P = 0·043) and there was a trend for food intake to be lower for pollutant-exposed pigs (control v. pollutant 292 v. 280 (s.e.d. = 7·1) kg per pen, P = 0·124). The reduction in live weight and food intake was dependent upon the concentration of dust (mean across all ammonia concentrations for increasing dust concentration; live weight 25·3, 26·4, 24·0 and 24·5 (s.e.d. = 0·65) kg, P = 0·081; food intake 295, 316, 248 and 263 (s.e.d. = 14·3) kg per pen, P = 0·016) but not ammonia (mean across all dust concentrations for increasing ammonia concentration; live weight 24·4, 25·1, 25·3 and 25·3 (s.e.d. = 0·41) kg, P = 0·158; food intake 279, 275, 288 and 279 kg (s.e.d. = 9·0) kg per pen, P = 0·520). There was an interaction between dust and ammonia for live weight (P = 0·030) but the effects were complicated and may have been the result of a type I error. There was no interaction for food intake (P = 0·210). In general, both food intake and live-weight gain, but not food conversion efficiency, were lower for weaned pigs exposed to 5·1 and 9·9 mg/m3 dust concentrations compared with 1·2 and 2·7 mg/m3 treatments. Other measures of production were also analysed and supported the overall interpretation that dust concentrations of 5·1 mg/m3 and higher depress performance.

This study is the first to quantify the effects of chronic exposure to common aerial pollutants on the performance of weaned pigs. The results suggest that dust concentrations of 5·1 or 9·9 mg/m3 (inhalable fraction) across ammonia concentrations up to 37 p.p.m. adversely affect performance. The commercial significance of these findings depends on the financial benefits of the superior production at low dust concentrations relative to the cost of providing air of this quality.


Corresponding author

Corresponding author. E-mail:


Hide All
Demmers, T. G. M., Wathes, C. M., Richards, P. A., Teer, N., Taylor, L. L., Bland, V., Goodman, J., Armstrong, D., Chennells, D. and Done, S. H. 2003. A facility for controlled exposure of pigs to airborne dusts and gases. Biosystems Engineering 84: 217230.
Doig, P. A. and Willoughby, R. A. 1971. Response of swine to atmospheric ammonia and dust. Journal of American Veterinary Medical Association 159: 13531361.
Done, S. H., Gresham, A. C. J., Chennells, D. J., Williamson, S., Hunt, B., Taylor, L. L., Bland, V., Jones, P., Armstrong, D., White, R. P., Demmers, T. G. M., Teer, N. and Wathes, C. M. 2004. The clinical and pathological responses of weaned pigs to atmospheric ammonia and dust. Veterinary Record In press.
Donham, K., Reynolds, S., Whitten, P., Merchant, J., Burmeister, L. and Popendorf, W. 1995. Respiratory dysfunction in swine production facility workers: dose-response relationships of environmental exposures and pulmonary function. American Journal of Industrial Medicine 27: 405418.
Drummond, J. G., Curtis, S.E., Simon, J. and Norton, H. W. 1980. Effects of aerial ammonia on growth and health of young pigs. Journal of Animal Science 50: 10851091.
Hamilton, T. C. D., Roe, J. M., Hayes, C. M., Jones, P., Pearson, G. R. and Webster, A. J. F. 1999. Contributory and exacerbating roles of gaseous ammonia and organic dust in the etiology of atrophic rhinitis. Clinical and Diagnostic Laboratory Immunology 6: 199203.
Hamilton, T. C. D., Roe, J. M., Hayes, C. M. and Webster, A. J. F. 1998a. Effects of ammonia inhalation and acetic acid pretreatment on the colonisation kinetics of toxigenic Pasteurella multocida within the upper respiratory tract of swine. Journal of Clinical Microbiology 36: 12601265.
Hamilton, T. C. D., Roe, J. M., Hayes, C. M. and Webster, A. J. F. 1998b. Effect of ovalbumin aerosol exposure on colonisation of the porcine upper airway by Pasteurella multocida and effect of colonisation on subsequent immune function. Clinical and Diagnostic Laboratory Immunology 5: 494498.
Hamilton, T. C. D., Roe, J. M. and Webster, A. J. F. 1996. The synergistic role of gaseous ammonia in the aetiology of P. multocida-induced atrophic rhinitis in swine. American Journal of Clinical Microbiology 34: 21852190.
Jones, J. B., Burgess, L. R., Webster, A. J. F. and Wathes, C. M. 1996. Behavi 5 M Enterprise, Sheffield.
Reynolds, S., Donham, K., Whitten, P., Merchant, J., Murmeister, L. and Popendorf, W. 1996. Longitudinal evaluation of dose-response relationships for environmental exposures and pulmonary function in swine production workers. American Journal of Industrial Medicine 29: 3340.
Robertson, J. F., Wilson, D. and Smith, W. J. 1990. Atrophic rhinitis: the influence of the aerial environment. Animal Production 50: 173182.
Turner, L. W., Wathes, C. M. and Audsley, E. 1993. Dynamic probabilistic modelling of atrophic rhinitis in swine. International winter meeting, Chicago, American Society of Agricultural Engineers, St Joseph, USA, paper no. 934559.
Wathes, C. M. 1998. Environmental control in pig housing. Proceedings of the 15th international Pig Veterinary Society congress, Birmingham, UK, vol. I (ed. Done, S., Thomson, J. and Varley, M.), pp. 257265. Nottingham University Press.
Wilkinson, J. 1996. Lack of research threatens UK pig herd. Veterinary Record 139: 223.



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed