Division 4.12.1 Description of floor types and techniques for reducing ammonia emissions in pig houses

United Kingdom

Type of floor	Description
Fully slatted floor	A floor where the whole area is slatted using metal, concrete or plastic floor with openings that allows faeces and urine to drop into a channel or a pit beneath.
Partly slatted floor	A floor that is partly solid and partly slatted using metal, concrete or plastic floor with openings that allows faeces and urine to drop into a channel or a pit beneath. Fouling of the solid floor is prevented by proper management of the indoor climate parameters, especially under hot conditions, and/or by proper design of the housing systems.
Solid concrete floor	A floor where the entire area consists of solid concrete. The floor can be covered with litter (e.g. straw) to varying degrees. The floor is usually sloped to facilitate the drainage of urine.

The floor types listed above are used in the described housing systems, when appropriate:

Technique	Description
A deep pit (in case of a fully or partly slatted floor) only if used in combination with an additional mitigation measure, e.g.: a combination of nutritional management techniques; air cleaning system; pH reduction of the slurry; slurry cooling.	Pens are equipped with a deep pit below the slatted floor that allows for the storage of the slurry between infrequent removals. For fattening pigs, an overflow manure channel can be used. Removal of slurry for landspreading or to outdoor store takes place as frequent as possible (e.g. at least every two months) unless there are technical restrictions (e.g. storage capacity).
A vacuum system for frequent slurry removal (in case of a fully or partly slatted floor).	Outlets at the bottom of the pit or channel are connected to a discharge pipe underneath which transfers slurry to outdoor storage. Slurry is frequently discharged by opening a valve or a plug in the main slurry pipe, e.g. once or twice every week; a slight vacuum develops and allows the complete emptying of the pit or channel. A certain depth of slurry needs to be obtained before the system can operate properly to allow the vacuum to be effective.
Slanted walls in the manure channel (in case of a fully or partly slatted floor).	The manure channel creates a V section with the point of discharge at the bottom. The slope and the smoothness of the surface facilitate the slurry discharge. Manure removal is carried out at least twice every week.
A scraper for frequent slurry removal (in case of a fully or partly slatted floor).	There is a V-shaped channel with two inclined surfaces on each side of a central gutter, where urine can be drained to a collection pit through a drain in the bottom of the manure channel. From the pit, the solid fraction of the manure is extracted frequently (e.g. daily) by a scraper. The addition of a coating on the scraped floor is recommended in order to achieve a smooth(er) surface.
Convex floor and separated manure and water channels (in case of partly slatted pens).	Manure and water channels are built at opposite sides of the convex and smooth solid concrete floor. The water channel is installed underneath the side of the pen where the pigs tend to eat and drink. Water for cleaning the pens may be used to fill the water channels. The channel is partially filled with at least 10 cm of water. The manure channel can be built with flashed gutters or slanted walls which are normally flushed twice every day for example with water from the other channel or the liquid fraction of the slurry (dry matter content no higher than approximately 5 %).
V-shaped manure belts (in case of partly slatted floor).	V-shaped manure belts roll inside the manure channels covering the whole surface, so that all faeces and urine are dropped on them. Belts are run at least twice every day to separately carry urine and faeces to closed manure storage. Belts are made of plastic (polypropylene or polyethylene).
Reduced manure pit (in case of partly slatted floor).	The pen is equipped with a narrow pit with a width of about 0,6 m. The pit can be placed in an external alley.
Frequent slurry removal by flushing (in case of fully or partly slatted floor).	A very frequent removal (e.g. once or twice per day) of the slurry is performed by flushing the channels with the liquid fraction of the slurry (dry matter content no higher than approximately 5 %) or water. The liquid fraction of the slurry can also be aerated before flushing. This technique can be combined with individual variations of the bottoms of channels or pits, e.g. gutters, tubes or a permanent slurry layer.
Kennel/hut housing (in case of partly slatted floor).	Separate functional areas are organised in the pens of naturally ventilated houses. The lying area (about 50-60 % of the total area) consists of a levelled insulated concrete floor with covered, insulated huts or kennels, with a hinged roof that can be raised or lowered to control temperature and ventilation. The activity and feeding areas lie on a slatted floor with a manure pit underneath and frequent manure removal, e.g. by vacuum. Straw can be used on the solid concrete floor.
Full litter system (in case of solid concrete floor).	A fully concrete floor almost completely covered with a layer of straw or other lignocellulosic material. In the litter-floored system, solid manure is frequently removed (e.g. twice per week). Alternatively in the deep litter system, fresh straw is added on top and the accumulated manure is removed at the end of the rearing cycle. Separate functional areas can be organised into lying, feeding, walking and defecating areas.
Littered external alley (in case of solid concrete floor).	A small door allows the pig to go out to defecate in an external alley with a concrete littered floor. The manure falls into a channel from where it is scraped once every day.
Feeding/lying boxes on solid floor (in case of litter-based pens).	Sows are kept in a pen divided into two functional areas, the main one littered and a series of feeding/lying boxes over a solid floor. Manure is captured in the straw or other lignocellulosic material, which is regularly supplied and replaced.
Manure collection in water.	Manure is collected in the cleaning water that is kept in the manure channel and refilled up to a level of around 120-150 mm. Slanted channel walls are optional. After each rearing cycle, the manure channel is emptied.
A combination of water and manure channels (in case of fully slatted floor).	The sow is kept in a fixed place (by using a farrowing crate) with a specific defecating area. The manure pit is split up into a wide water channel at the front and a small manure channel at the back, with a reduced manure surface. The front channel is partly filled with water.
Manure pan (in case of fully or partly slatted floor).	A prefabricated pan (or pit) is placed under the slatted floor. The pan is deepest at one end with a slope of at least 3° towards a central manure channel; the manure discharges when its level reaches around 12 cm. If a water channel exists, the pan can be subdivided into a water section and a manure section.
Straw flow system (in case of solid concrete floor).	Pigs are reared in pens with solid floors, where a sloped lying area and an excretion area are defined. Straw is provided to the animals daily. Pig activity pushes and distributes the litter down the pen's slope (4-10 %) to the manure collection aisle. The solid fraction can be removed frequently (e.g. daily) with a scraper.
Littered pens with combined manure generation (slurry and solid manure).	Farrowing pens are equipped with separate functional areas: a bedded lying area, walking and dung areas with slatted or perforated floors, and a feeding area on a solid floor. Piglets are provided with a littered and covered nest. Slurry is frequently removed with a scraper. Solid manure is manually removed from the solid floor areas on a daily basis. Litter is regularly provided. A yard can be combined with the system.
Use of floating balls in the manure channel.	Balls half-filled with water and made of special plastic with non-sticky coating, float on the surface of the manure channels.