Division 4.13.1 Techniques for reducing ammonia emissions from houses for laying hens, broiler breeders or pullets
United Kingdom
| Housing system | Description |
|---|---|
| Unenriched cage system | Broiler breeders are housed in unenriched cage systems fitted with perches, litter area and nest. Pullets should be given appropriate experience of management practices (e.g. particular feeding and watering systems) and environmental conditions (e.g. natural light, perches, litter) to enable them to adapt to the husbandry systems which they will encounter later in life. The cages are usually arranged on three or more tiers. |
| Enriched cage system | Enriched cages are built with sloping floors, are made of welded wire mesh or plastic slats and are equipped with fixtures and increased space for feeding, drinking, nesting, scratching, perching and egg collection. The capacity of the cages can vary from around 10 to 60 birds. The cages are usually arranged on three or more tiers. |
| Deep litter with manure pit | At least one-third of the total floor in the housing is covered with litter (e.g. sand, wood shavings, straw). The remaining floor area is slatted, with a manure pit underneath. Feeding and drinking fixtures are located over the slatted area. Additional structures can be present inside or outside the housing, such as verandas and free-range system. |
| Aviaries | Aviaries are divided into different functional areas for feeding, drinking, egg laying, scratching and resting. The usable area is increased by means of elevated slatted floors combined with tiers. The slatted area ranges between 30 % and 60 % of the total floor area. The remaining floor is typically littered. In plants for laying hens and broiler breeders, the system can be combined with verandas with or without free-range system. |
| X1Technique | Description |
| Manure removal by belts (in case of enriched or unenriched cage systems) with at least:
| Belts are placed under the cages for manure removal. The frequency of removal can be once every week (with air drying) or more (without air drying). The collection belt may be ventilated for drying the manure. Whisk-forced air drying in the manure belt can be also used. |
| Manure belt or scraper (in case of deep litter with a manure pit). | Manure is removed by scrapers (periodically) or by belts (once every week for dried manure, twice every week without drying). |
| Forced ventilation system and infrequent manure removal (in case of deep litter with a manure pit) only if used in combination with an additional mitigation measure, e.g.:
| The deep litter system (see above for description) is combined with infrequent manure removal, e.g. at the end of the rearing cycle. A minimum dry matter content of manure of around 50-60 % is ensured. This is achieved by an appropriate forced ventilation system (e.g. fans and air extraction placed at floor level). |
| Forced air drying of manure via tubes (in case of deep litter with a manure pit). | The deep litter system (see above for description) is combined with manure drying by means of forced ventilation applied through tubes that blow air (e.g. at 17-20 °C and 1,2 m3/bird) over the manure stored under the slatted floor. |
| Forced air drying of manure using perforated floor (in case of deep litter with a manure pit). | The deep litter system (see above for description) is equipped with a perforated floor placed underneath the manure which allows for forced air blowing from below. The manure is removed at the end of the rearing cycle. |
| Manure belts (in case of aviary). | Manure is collected on belts under the slatted floor and removed at least once every week by ventilated or not ventilated belts. Littered and solid floors can be combined in aviaries for pullets. |
| Forced drying of litter using indoor air (in case of solid floor with deep litter). | In a deep litter system without a manure pit, indoor air recirculation systems can be used to dry the litter, while meeting the physiological needs of the birds. To this end, fans, heat exchangers and/or heaters can be used. |