Livestock farmers continue to express concern about animal safety during manure removal from deep pitted barns. Wheat will be harvested soon and as stubble fields become available many farmers will be pumping pits, covering those fields with manure. Now is an opportune time to review the recommended practices for avoiding animal losses during pit agitation and manure pumping.
- When hauling manure do not enter, and do not let any employees enter, the room being pumped. The risk to human life is too great to allow for visual monitoring.
- Manure foam is 60 – 70 percent methane; be extremely cautious when pumping foaming pits. Reduce the risk of explosion by turning off all heaters, pilot lights and non-ventilation electrical equipment in the room being pumped.
- Enforce no smoking rules in and around barns. Again, manure foam has a high concentration of methane. Smoking in and around barns increases the opportunity for an accident.
- Reduce static pressure within the barn by increasing the air inlet opening. Lowering static pressure helps ensure that wall fans don’t overpower the pit ventilation and draw pit gases up into the air space above the slats.
- Use a tarp or other flexible material to seal around the manure pump and agitation return on the pump out ports where equipment has been installed. If left uncovered these ports serve as air inlets to the manure pit and reduce the effectiveness of the pit fans and ventilation system in the animal area. Be sure all covers on unused pump out ports are in place as well.
- Maximize ventilation during warm weather.
- During cool weather set the pit ventilation at its maximum level and run at least one wall fan (20 – 30 CFM per pig, minimum).
- Naturally ventilated barns depend upon, at a minimum, a 5 mph breeze to circulate air through the animal space. Avoid agitating manure below naturally ventilated barns when the outside air is calm and stable. Use stir fans when they are available.
- If the pit is nearly full of manure or a combination of manure and foam, don’t start agitating until 2 - 3 feet of manure has been removed from the pit. Lack of air space between the surface of the manure and the slatted floor reduces the effectiveness of the pit ventilation and allows gases to escape into the animal area above the slats.
- Discharge all agitated manure under the manure surface. Do not shoot manure over the surface (rooster tail) and do not shoot manure against walls and pillars. As the pit empties shut down the agitation when the returning stream begins to disturb the manure surface.
- Allow the ventilation system to operate at increased levels for at least 30 minutes after disturbing the manure.
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