GB2516320A

GB2516320A - Game bird rearing

Info

Publication number: GB2516320A
Application number: GB1313720.3A
Authority: GB
Inventors: Matthew Hudson
Original assignee: GOLDEN M Ltd
Current assignee: GOLDEN M Ltd
Priority date: 2013-07-19
Filing date: 2013-07-31
Publication date: 2015-01-21
Also published as: GB201313720D0; GB201312977D0

Abstract

Rearing house for young animals, specifically game birds, comprising, a heating system embedded in the floor 4. The system uses heated water continuously circulated by a pump P through conduit 2 to maintain a constant temperature. At least one sensor 14 is used to trigger a control system 12 which opens a valve 8 to direct water to the heater 6. There may be more than one sensor in the brooder to detect conduit, floor and or air temperature. The pump may be operated at a constant speed. The water heater could be activated only when needed. The controller may be set to pre-programmed temperature profile to prepare the animal for being released. The flooring may form a continuous sealed surface extending across the entire floor, which may extend up one or more of the walls. Also included is a method for rearing young birds using the apparatus disclosed.

Description

Intellectual Property Office Applicacion Nc,. (lB 1313720.3 RTM Dace:3 Dircinbcr 2013 The following terms are registered trade marks and should he rcad as such wherever they occur in this document: Celotex Inlelleclual Property Office is an operaling name of the Pateni Office www.ipo.gov.uk Game Bird Rearing The present invention relates to installations for rearing young birds or animals, and in particular (but not exclusively) to installations for rearing game birds, especially pheasants.

The game shooting industry has been quoted as being worth £1.6 billion to the UK economy. Approximately 40 million game birds are estimated to be raised in Great Britain each year for shooting, of which the majority (at least 80%) are pheasants and most of the rest are red-leg partridge. A few grey partridge and ducks are also farmed. Other game birds, e.g. grouse, quail and ducks, are managed in wild habitats rather than being reared. Pheasants may be hatched from eggs on farms in or else imported, mostly from Europe e.g. France, as eggs or day-old chicks.

The pheasant chicks are reared intensively on the farm before release to the wild for shooting when the season begins.

Game birds have traditionally been bred and reared using simple systems of husbandry. Most game bird farmers use low tech' or traditional equipment.

Commercial poultry systems e.g. known for chicken production, are not generally used to breed game birds. Pheasants are reputedly difficult to rear intensively and are prone to welfare problems, such as pecking. Brooding temperatures can be a critical factor in rearing pheasant chicks. Estimates suggest that around 5% of chicks die in the first two weeks and a further 5% die prior to being placed in the release pens. These figures can vary from year to year, and between estates, in any given year. Weather conditions, bird health and hygiene may all contribute to the variation. A poorly managed pheasant brooder i.e. rearing house may suffer from relatively high mortality rates.

Newly hatched chicks or bought-in poults are placed in a brooder house that provides heat and ventilation in controlled conditions. The chicks are reared under heat for the first three weeks. Heat is gradually reduced and space increased as the birds grow so that by the time their feathers have developed the birds can be given access to outside runs and become acclimatised to being outdoors. They are then be moved to small, enclosed pens until they are fully feathered and ready to be moved to larger release pens.

In the tirst few weeks, chicks are usually confined to brood rings located under suspended brooder hoods that may be air-heated, for example as seen in US 4,637,343. Chicks are not able to control their own body temperature for the first three weeks of life, and thus are very susceptible to changes in temperature in the brooder house. The brooder heaters are usually controlled to provide an air temperature in the range of 30-37 °C in the rings, although temperatures up to 40 °C may be experienced directly under the heater. Traditional thinking is that the chicks can stay comfortable by moving around under the heaters, but in practice movement is limited by the rings and this can result in the problem of bunching.

Pheasant chicks are prone to feather picking problems, which commonly occur when reared in large numbers in confinement, but which can be exacerbated by improper temperature control.

Brooding temperatures are a critical factor in rearing pheasant chicks. The brooder room temperature should be at least 32 °C for the young birds and higher for newly hatched chicks. When the chicks are one week old, the temperature is usually dropped one degree every other day, increasing to one degree every day when they reach three weeks of age. When the chicks go outside at six weeks of age they should be acclimated to the lowest outside temperature. Depending on the time of year, the temperature may need to be lowered a few additional degrees each day approximately one week before the chicks are allowed outside. However it has been found difficult to reliably maintain brooder houses at a constant temperature, especially when the outside temperature may be fluctuating greatly e.g. during spring and early summer. Unreliable brooder temperatures may be a prime contributor to chick mortality rates.

Biosecurity is also highly important for successful rearing. The main diseases affecting game birds are Hexamitiasis, Trichomanasis and rotavirus (in chicks), Coccidiosis and parasitic worms. Good housing and heating are required to provide steady temperature control in the first few weeks. Stressors that can affect a bird's ability to fight parasitic infections include rapid variations in housing temperature, problems with the water or food quality, other disease conditions such as bacterial enteritis, and competition from other birds in the room. Traditional brooder houses are not easy to clean and tend to harbour disease.

The remains a need for improvements in bird rearing i.e. brooder rooms.

According to a first aspect of the present invention there is provided an installation for rearing young birds or animals, the installation comprising a rearing house having a floor and a water heating system for the floor, the water heating system comprising: a conduit for heated water, the conduit being embedded in the floor; a heat distribution layer arranged in thermal contact with the conduit and substantially extending across the floor; a water heater, a pump and a controller arranged to continuously circulate a substantially fixed volume of heated water through the conduit; and at least one sensor arranged to detect a temperature of the floor and/or conduit; wherein the controller is arranged to act, in response to the at least one sensor, to selectively open flow communication between the heater and the conduit for a finite period of time, so that at least some of the fixed volume of water is re-heated by the heater such that the floor is maintained at a substantially constant temperature.

It will be appreciated that such an installation replaces traditional air i.e. convection heating with under-floor heating, which is much more energy efficient than heating the air above the chicks and using fans to push the warmth down to floor level.

Furthermore, the water heating system has been found to achieve even greater efficiency than existing underfloor heating systems by circulating a substantially fixed volume of heated water and only selectively re-heating the water in batches i.e. intermittently as determined necessary to maintain the floor temperature. The controller is able to determine when water is to be diverted to the heater, and for how long, using intelligence from the sensor(s). By using a fixed volume (i.e. closed loop) system, a connection to a mains water supply is not required, so the installation may be located remotely e.g. close to rearing pens in woodland. This may remove the need to transport chicks in crates after they have been reared.

The water heating system comprises at least one sensor arranged to detect a temperature of the floor and/or conduit, which can be used by the controller to determine when to open flow communication between the heater and the conduit, and for how long. It has been found that the conduit temperature, which is representative of the temperature of the heated water being carried by the conduit, may fluctuate by up to 10 °C, 15 °C, 20 00 or more at a given point in the system.

However, the floor temperature is maintained substantially constant due to the constant circulation of the heated water and mixing that occurs. The controller may be able to determine when it is necessary to dived some of the circulating water to be re-heated based solely on a sensor arranged to detect a temperature of the conduit. The sensor may be positioned in thermal contact with the conduit at a point downstream of the pump, preferably at a point where water has already flowed through the floor. Such a "hot return" can give an idea of the amount of heat transferred to the floor. Of course the sensor may instead be positioned in thermal contact with the conduit at any other point in the system. The sensor may be placed in thermal contact with the conduit rather than in direct contact with the heated water so as to avoid the need for an immersed sensor and sealing.

However a sensor that protrudes through the conduit to be in direct contact with the heated water may also be used if desired.

In one set of embodiments the water heating system comprises at least one sensor arranged to detect a temperature of the conduit and at least one sensor arranged to detect a temperature of the floor. The floor temperature sensor may advantageously be used by the controller to provide for fine tuning after an initial determination based on the conduit temperature. For example, if re-heating results in an overshoot of the floor temperature, or an under-temperature, then this can be detected quickly and compensated for. In at least some embodiments the heating system comprises at least one sensor arranged to detect an air temperature in the rearing house, preferably in addition to the conduit sensor and/or floor sensor. This sensor may provide an additional check in the event of a false reading by one or more other sensors in the system. The air temperature sensor (e.g. a thermistor) may be positioned in the rearing house above floor level, for example positioned closer to the ceiling than to the floor.

The controller is preferably an electronic controller comprising a microprocessor arranged to act in response to signals from the one or more sensors. The sensor(s) may take the form of electrical sensors, e.g. a thermistor. The controller could be arranged to control the pump while water is being circulated, for example repeatedly turning it on/off for pulsed operation or adjusting the pump speed to control circulation of the heated water. However, it is preferable that the pump is operated at a constant speed. The pump is preferably an electric pump.

Accordingly the power draw of the pump may be substantially constant, which can be especially beneficial if the system is run by an electrical generator rather than a mains electrical supply. Again, this means that the installation is well suited for remote locations. Similarly, the controller could be arranged to control the water heater, for example turning it on/off or adjusting the temperature to which water is heated. However, in addition or alternatively, it is preferable that the controller is not directly linked to the water heater. Thus in preferred embodiments the water heater and/or pump do not receive any control signals from the controller, or at least during steady state circulation. The controller may be linked to the pump (and possibly the water heater) solely to connect/disconnect electrical power when the entire water heating system is to be turned on/off. Otherwise the controller is used to control the flow of water through the system as will be described below.

It is an advantage of the water heating system that the controller is used mainly, and preferably solely, to open/close flow communication between the heater and the conduit while heated water is being circulated. When the flow communication is closed then the conduit is a closed loop including the pump. When the flow communication is open then at least some of the water circulating through the loop is diverted to the water heater to be re-heated. The water heating system may include at least one flow control valve that is operated by the controller to open flow communication between the heater and the conduit. Preferably the water heating system includes two flow control valves, a flow inlet valve located in the conduit upstream of the heater's water inlet and a flow outlet valve located in the conduit downstream of the heater's water outlet. This means that the inlet and outlet valves can be controlled independently and opened/closed at different times.

As is mentioned above, it is preferable that the controller is not arranged to directly control the water heater. The water heater may therefore operate to turn itself on/off when it is put into flow communication with the conduit. This could be achieved by connecting the flow inlet valve to the water heater such that its opening triggers heating. However, in a preferred solution the water heater comprises a pressure-operated heater control, for example a diaphragm located at the heater's water inlet. When flow communication with the conduit is closed then there is no water pressure to operate the heater. When flow communication with the conduit is open then a pressure differential is created which can operate the heater control e.g. diaphragm so that the water heater is turned on. When flow communication with the conduit is closed, the pressure drops and the diaphragm returns so that the heater turns itself off. If the water heater is a gas water heater then the pressure-operated heater control may simply open/close a gas burner valve. If the water heater is an electric water heater then the pressure-operated heater control may connect/disconnect the electrical power supply to the water heater. A gas water heater is preferred as it does not require a mains supply or generator and can simply use bottles of gas.

The water heater may be set to heat water to a fixed temperature. In one example, the water heater may be set to heat water to at least 25°C above ambient temperature! and possibly up to 40 °C or even 50 °C above ambient temperature.

The water heater may optionally be provided with a water temperature selector, but it is not necessary for a user to adjust the temperature achieved by the water heater as the controller is able to maintain the floor temperature regardless of the temperature to which water in the conduit is heated. For example, the higher the temperature setting of the water heater the smaller the time period that flow communication between the heater and the conduit is open.

The efficiency and accuracy of the water heating system may also be ensured by using a water heater that has a much smaller volume than the volume of water being circulated through the conduit. Preferably the fixed volume of water in the conduit is at least 50 or 60 times greater than the volume of the water heater.

Further preferably the fixed volume of water in the conduit is at least 70, 80, 90 or times greater than the volume of the water heater. A larger volume of circulating water may help to avoid evaporation. This has been found helpful for achieving a substantially constant floor temperature. It is an advantage of the water heating system that it can be scaled up or down depending on the size of a particular installation.

Any suitable pump can be used to ciiculate heated watei in the conduit. In at least some embodiments it may be preferable for the pump to provide a water pressure of at least 1 bar, and preferably around 1.5 bar, so that there is a sufficient pressure differential to operate a pressure-operated heater control, where one is provided.

The construction of the floor can also contribute to the ability of the water heating system to maintain a substantially constant floor temperature. It will be appreciated that the conduit being embedded in the flooi means that the conduit is not exposed to birds or animals in the rearing house. Heat is conducted from the water flowing in the conduit, through the conduit walls to the floor. To optimise this heat transfer, a heat distribution layer is arranged in thermal contact with the conduit and substantially extends across the flooi. Of course one or moie heat distiibution layers may be used. In one embodiment, the heat distribution layer comprises a foil layer underneath the conduit and a sheet layer above the conduit. The more flexible foil layer conforms to the outer walls of the conduit and extends around the walls of the conduit to contact the sheet layer above. Together the heat distribution layers therefore surround the conduit.

The heat distribution layer(s) may be made of a conductive material such as aluminium. It will be appreciated that the heat distribution layer(s) may not extend entirely to the perimetel edges of the floor, but pieferably they do.

In a preferred set of embodiments the floor comprises a heat distribution layer, e.g. a sheet layer, arranged over the conduit and having sufficient thermal mass to maintain the floor at a substantially constant temperature. For a sheet aluminium layer, it has been found that a thickness of at least 3 mm works better than thinner layers. The floor may include one or more furthei layers that can assist the heat distribution layer in maintaining the substantially constant temperature. For example, the floor may further comprise one or more thermal insulation layers e.g. formed of an open cell material. The thermal insulation layer(s) may be arranged under the conduit to prevent heat loss. In addition, oi alternatively, the floor may comprise one or more layeis of theimal reflective insulation, e.g. aluminium foil bonded to insulating foam or bubble sheeting.

Preferably the floor is maintained at a substantially constant temperature of 38 °C +1-0.5 °C when the installation is housing newly hatched chicks. The controller may be pre-programmed with a floor temperature profile that changes in time e.g. gradually decreasing the temperature as the chicks grow. The floor temperature program may be initiated when the water heating system is turned on at day one for a new batch of hatchlings. The controller may then automatically reduce the floor temperature in the following days and weeks according to the program, so that no user input is required. The controller may be linked to a weather station, which can be used to adjust the floor temperature program in response to conditions outside the installation. The installation itself may include a weather station, or the controller may be linked to a separate weather station (wirelessly or using physical connection).

A benefit of the floor temperature being maintained substantially constant (at any particular point in a pre-programmed temperature profile) is that it ensures the droppings on the floor are always properly dried out. This can prevent the spread of infection and make the installation easier to clean out. The rearing house may further comprise ventilation to aid in the removal of ammonia.

Another aspect of biosecurity is to eliminate floor contamination so that disease is not spread from one batch of chicks to another. The Applicant has recognised that biosecurity can be improved by sealing the surface of the heated floor. This is in contrast to some conventional brooder floors, which comprise a wire mesh extending over heating pipes so that droppings can fall through the floor to be collected below. Instead, the controlled floor temperature is used to dry out the droppings so that they can be easily removed from the floor itself. Thus in a preferred set of embodiments the floor comprises an upper layer in thermal contact with the heat distribution layer and forming a continuous sealed surface extending across the floor.

This is considered novel and inventive in its own right, and thus according to a second aspect of the present invention there is provided an installation for rearing young birds or animals, the installation comprising a rearing house having a floor and a water heating system for the floor, the water heating system comprising: a conduit for heated water, the conduit being embedded in the floor; a water heater, a pump and a controller arranged to continuously circulate a substantially fixed volume of heated water through the conduit and maintain the floor at a substantially constant temperature; a heat distribution layer arranged in thermal contact with the conduit and substantially extending across the floor; and a continuous sealed surface layer in thermal contact with the heat distribution layer.

The continuous sealed surface layer may be a substantially planar surface e.g. forming an upper surface of the floor. However the Applicant has appreciated that biosecurity may be improved by extending the sealed surface layer at least partly up the walls of the rearing house, so that there are no cracks at the edges of the floor where faecal matter may accumulate. In a set of embodiments (according to either aspect of the invention) the rearing house includes walls and the continuous sealed surface layer extends from the floor up one or more of the walls.

An installation according to the second aspect of the invention may have any of the features already described hereinabove. There will now be described some further features applicable to either aspect of the invention.

Game birds, and in particular pheasant chicks, are prone to feather picking problems. These commonly occur whenever birds are grown in large numbers in confinement. Feather picking may be intensified by lack of feed or water, nutritional deficiencies, improper temperatures, overcrowding or the use of bright lights that shine directly upon the chicks. Once feather picking begins it is difficult to control.

Feather picking and cannibalism may be controlled by attaching anti-picking devices, such as bits (small plastic C-shaped clips fitted to the beaks) or peepers, or even by de-beaking procedures. Chicks are often "bitted" at 2-3 weeks of age.

However these procedures can cause welfare concerns.

The Applicant has recognised that one way to mitigate feather picking problems is to prevent the birds from huddling in the rearing house. Advantageously, this may be achieved using the layout of the heated water conduit in the floor. In a preferred set of embodiments the conduit is laid in a serpentine pattern with a spacing Si between adjacent runs of the conduit. Preferably the spacing Si is substantially -10-constant so that the floor is evenly heated and there are no "hot spots" that might attract a huddle of birds or animals. However it is preferable that there is a spacing S2, between the conduit and the perimeter of the floor, that is larger than Si. This means that the floor temperature may drop slightly towards the edges so that the birds or animals are less likely to huddle along the walls or in corners of the rearing house. The spacing S2 may be at least 1.5, 1.6, 1.7, 1.8, 1.9 or about 2 times greater than the spacing Si. For example, if the main conduit spacing Si is about mm then the perimeter spacing 52 may be about 400 mm.

In addition, or alternatively, one or more other means may be used to mitigate feather picking. For example, the rearing house may include red lighting to avoid pecking. In another example, the rearing house may have a floor that comprises at least two different levels connected by a slope. This acts like a weir so that huddles of birds are forced to slide down from one level to another and become separated.

The installation may further comprise one or more of the following features: -an outdoor run to allow the birds to acclimatise to outdoor living after release; -visible and/or infrared lighting; -surveillance cameras inside and/or outside the rearing house, to enable surveillance of the birds and/or for security purposes; -air vents in opposite walls of the rearing house for a cross-flow of air; -water feeders, for example water channels provided with nipple feeders; -dry feed channels.

It has been found that birds will spread evenly in the rearing house rather than huddling under brooder hoods, as in conventional brooder houses, so they have better access to feeders. Water and/or dry feed channels can extend across the rearing house rather than only providing local feeders at each heated brood ring.

The rearing house may be a permanent or semi-permanent structure. However, as game birds are only reared at certain times of the year it may be desirable for the rearing house to be mobile, designed to be dismantled or collapsible. In one set of embodiments the rearing house consists of panels connected by releasable joints.

When the house is not in use, the panels can be separated and stacked for storage and/or transportation. -11 -

The present invention extends to use of a rearing house (i.e. a brooder house) as described herein to rear pheasant chicks up to six weeks of age.

According to a further aspect of the present invention there is provided a method of rearing young birds or animals, in particular game birds, and preferably pheasants, comprising: housing the young birds or animals in a rearing house having a floor and a water heating system for the floor, the water heating system comprising: a conduit for heated water, the conduit being embedded in the floor; a heat distribution layer arranged in thermal contact with the conduit and substantially extending across the floor; a water heater, a pump and a controller arranged to continuously circulate a substantially fixed volume of heated water through the conduit; and at least one sensor arranged to detect a temperature of the floor and/or conduit; and controlling the water heating system, in response to the at least one sensor, to selectively open flow communication between the heater and the conduit for a finite period of time, so that at least some of the fixed volume of water is re-heated by the heater such that the floor is maintained at a substantially constant temperature.

Preferably the method comprises maintaining the floor at a substantially constant temperature of 38 00 +/-0.5 00, e.g. at least when housing newly hatched chicks, in particular pheasant chicks. Such methods may include any of the features of a rearing house in an installation already described hereinabove.

A preferred embodiment of the present invention will now be described, by way of example only, and with reference to the accompanying Figures, in which: Figure 1 is a schematic diagram of a water heating system; and Figure 2 is a schematic cross-sectional diagram of a floor in a rearing house.

There is seen in Figure 1 the water heating system of game bird rearing house, including a conduit 2 for heated water leading to/from the floor 4 of the rearing house. A pump P causes a substantially fixed volume, e.g. 15-20 litres, of water to continuously circulate through the conduit 2. A water heater 6 can be selectively -12-put into flow communication with the conduit 2 by valves 8, 10. The valves 8, 10 can be operated by a controller 12 in response to the conduit temperature detected by a sensor 14. When the valve 8 is opened, at least some of the fixed volume of water in the conduit 2 is diverted to the water heater 6 to be re-heated. The valve 10 may be opened at the same time or after a delay. The floor 4 is thereby maintained at a substantially constant temperature.

The water heating system optionally includes an expansion chamber 16 and an air release outlet 18.

There is seen in Figure 2 a schematic cross-section (not to scale) of a rearing i.e. "brooder" house 20 having a water-heated floor 4 and walls 22. The floor 4 is made up of various layers from top to bottom: a sealed surface layer 24; an aluminium heat distribution layer 26 in contact with the heated water conduit 2; an aluminium foil layer 28 encapsulating the conduit 2; a thermal insulation layer 30 e.g. of Celotex or the like; a reflective foil insulation layer 32; and another thermal insulation layer 34. Two further temperature sensors can be seen -a sensor 36 embedded in the floor 4 and a sensor 38 to measure the air temperature in the house 20. The sensors 36, 38 may provide temperature measurements for the controller 12 seen in Figure 1.

Example

An installation as described above was used to rear batches of pheasant chicks during a period from November to July. During this time the water heating system was run continuously with the same fixed volume of water. Each batch of around 4000 chicks was reared for six weeks with a decreasing floor temperature profile being applied by the controller. The temperature control was found to be very accurate; initially maintaining the floor at a temperature of 38 °C +1-0.5 °C. Very low mortality rates were observed. The system proved to be extremely energy efficient, using only half a canister of gas to run the water heater in that period -as compared to around 90 canisters for a conventional brooder house of the same size. -13-

Claims

Claims 1. An installation for rearing young birds or animals, the installation comprising a rearing house having a floor and a water heating system for the floor, the water heating system comprising: a waler heater; a conduit for heated water, the conduit being embedded in the floor; a heat distribution layei arianged in thermal contact with the conduit and substantially extending across the flooi; a pump and a controller arranged to continuously circulate a substantially fixed volume of heated water through the conduit; and at least one sensor airanged to detect a temperatule of the floor and/or conduit; wherein the controller is arranged to act, in response to the at least one sensor, to selectively open flow communication between the heater and the conduit foi a finite peiiod of time, so that at least some of the fixed volume of watel is re-heated by the heater such that the floor is maintained at a substantially constant temperature.
2. An installation according to claim 1, comprising at least one sensor arranged to detect a temperature of the conduit and at least one sensoi arianged to detect a temperature of the floor.
3. An installation according to claim 1 or 2, comprising at least one sensor arranged to detect an air temperature in the rearing house.
4. An installation accoiding to any preceding claim, wheiein the pump is operated at a substantially constant speed.
5. An installation according to any preceding claim, wherein the controller is arianged to operate a flow control valve so as to selectively open and/oi close flow communication between the heater and the conduit while heated watel is being circulated. -14-
6. An installation according to claim 5, comprising a flow inlet valve located in the conduit upstream of the water heater and a flow outlet valve located in the conduit downstream of the water heater.
7. An installation according to any preceding claim, wherein the water heater comprises a pressure-operated heater control.
8. An installation according to claim 7, wherein the heater control is operated when flow communication between the heater and the conduit is opened.
9. An installation according to claim 7 or 8, wherein the water heater is turned off when flow communication with the conduit is closed.
10. An installation according to any preceding claim, wherein the water heater is set to heat water to a fixed temperature.
11. An installation according to any preceding claim, wherein the controller is pre-programmed with a floor temperature profile that changes in time.
12. An installation according to any preceding claim, wherein the floor comprises an upper layer in thermal contact with the heat distribution layer and forming a continuous sealed surface extending across the floor.
13. An installation for rearing young birds or animals, the installation comprising a rearing house having a floor and a water heating system for the floor, the water heating system comprising: a water heater; a conduit for heated water, the conduit being embedded in the floor; a pump and a controller arranged to continuously circulate a substantially fixed volume of heated water through the conduit and maintain the floor at a substantially constant temperature; a heat distribution layer arranged in thermal contact with the conduit and substantially extending across the floor; and a continuous sealed surface layer in thermal contact with the heat distribution layer. -15-
14. An installation according to claim 12 or 13, wherein the rearing house includes walls and the continuous sealed surface layer extends from the floor up one or more of the walls.
15. An installation according to any preceding claim, wherein the conduit is laid in a serpentine pattern with a spacing Si between adjacent runs of the conduit.
16. An installation according to claim 15, wherein the conduit is laid with a spacing S2, between the conduit and the perimeter of the floor, that is larger than Si.
17. An installation according to any preceding claim, wherein the floor comprises at least two different levels connected by a slope.
18. An installation according to any preceding claim, wherein the rearing house consists of panels connected by releasable joints.
19. A method of rearing young birds or animals, in particular game birds, and preferably pheasants, comprising: housing the young birds or animals in a rearing house having a floor and a water heating system for the floor, the water heating system comprising: a water heater; a conduit for heated water, the conduit being embedded in the floor; a heat distribution layer arranged in thermal contact with the conduit and substantially extending across the floor; a pump and a controller arranged to continuously circulate a substantially fixed volume of heated water through the conduit; and at least one sensor arranged to detect a temperature of the floor and/or conduit; and controlling the water heating system, in response to the at least one sensor, to selectively open flow communication between the heater and the conduit for a finite period of time, so that at least some of the fixed volume of water is re-heated by the heater such that the floor is maintained at a substantially constant temperature. -16-
20. A method according to claim 19, comprising maintaining the floor ata substantially constant temperature of 38 °C ÷1-0.5 °C.