Right now with have some info...Suggest you evaluate the amount of dust, and possible water mist when cleaning down, as most animal pens use steam cleaners. A commercial alarm panel would be best here, with siren/strobe on outside of building, as i believe sounders are really painful to animals ears. If the dust level is fairly low the ionization smokes will be required, optical are no use in this enviroment. If there is alot of dust and water spray, a optical beam detector can be powered and linked off the control panel. Placed 500mm below the highest point of the roof, it can be adjusted to most situations. would suggest Fire Beam Company units, very easy to setup, cheaper and quicker than fitting 3 or 4 detectors down the building....hope this helps