Animal Hygienic Principles Of Construction And Reconstruction Of Stables Flashcards
Animal hygienic principles of stables
- protection from weather extremes and predators
- meeting the ethological demands of farmed animals and the ergonomic needs of farmers
General considerations
- construction elements
- technological systems
- cheap, old barns
- modern barns
- what the vet should know about the structure?
Construction elements
‣ base/footing of the house ‣ walls ‣ roofing ‣ floor ‣ windows/doors/gates ‣ Separation from the environment ‣ Protects the animals and the technological systems ‣ Long lifetime
Technological systems
‣ Thephilosophyofthesystem • tied down/loose keeping • keeping with/without bedding • closed/open confinements etc. ‣ Technical/engineering equipment systems that realize philosophy • system of ventilation • feed distribution (solid/wetetc.) • cages/batteries etc.
Cheap old barns
‣ Technological systems ‣ Simple structure ‣ Cheap to build ‣ Cleaning by hand ‣ Human labor required
Modern barns
‣ Technological systems can be changed
‣ Large number of animals
‣ Usually framework based animal shed/stable
What the vet should know about the structure?
◦ Physical/ thermal/ biological properties of building materials
◦ Hygienic requirements for walls/ windows/ roofs/ floors
◦ Ventilation/ heat balance of closed animal stables
Properties of building materials
• Thermal characteristics ◦ Long term effect on thermal properties of the building • Disinfectibility • Not poisonous or radioactive ◦ Asbestos ◦ Dross
Physical/ thermal/ biological properties of materials
- Density: kg/m3 (δ)
- Specific heat:kJ/kg* (c)
- Heat capacity: δ/c (kJ/m3)
- Thermal conductivity
- Thermal transmittance (U)
Density
kg/m3 (δ)
Specific heat
- kJ/kg (c)
- amount of heat required to increase the temperature by 1 C of a material of 1 kg mass
Heat capacity
- δ/c (kJ/m3)
- Equal to the ratio of the heat added to (or removed from) an object to the resulting temperature change
Thermal conductivity
- Ability of homogenous material to conduct heat.
- Amount of heat passing through 1m2 x-section of a material when a temperature difference of 1oC is maintained between opposite surfaces of 1m thickness
Thermal transmittence
- (U)
- Amount of heat (watts) transmitted through 1m2 surface of a construction from the air inside to the air outside when there is a 1oC difference between inside and outside.
- Should be <2.8
Vapour transmittancen
- Water vapour transmitted through 1m2 surface of stable construction from indoor to outdoor.
- 1 Hgmm difference in aerial vapour pressure
Thermal characteristics of building
- thermal lag:
- how fast will the temp change inside if it changes outside the building
- depends on heat capacity (C)
- thermal damping:
- how big temp difference can be between the inside and outside
Walls
- foundation: weight bearing, min. 50-70cm
- basement: first 30-50cm, water sealing, good insulation is important
- material: brickwork, concrete block etc.
- general demands: good heat characteristics, strong, fire resistant, simple easy cheap
- animal hygienic demands: good heat isolation, make vapour diffusion possible, vapour sealing inside, no precipitation, resistant against rodents
Doors and windows
• Proper sealing
• Wind-break: If cold sensitive animals are in the barn, Storage room, Canvas
• Doors: Animals can go through easily, Do not cause harm, Opens both ways Or to the main direction, 2 doors/stables
• Windows: Illumination, Air change: Carefully! in Winter (heatloss)
• Position of the windows: in the walls, in the roof skylight
• Stables wider than 12m should have roof windows for the sake of illumination
◦ Too much heat gain in summer
◦ Too much heat loss in winter
Roof
• Demands for the roof of animal houses:
◦ well insulated, most of the heat lost here
◦ good vapor transmittance
◦ light coloured and heat reflective (to decrease the solar heat gain)
◦ Roofshell: protection against precipitation
◦ Ceiling:
‣ heat insulation (requested insulation: 17-21kW/m2)
‣ carrying weights (e.g.storing grains, hay,etc.)
Floor
- bedding material +/-
- straw bedding: good foot holding, soft, good thermal properties, water absorption, lessens the germ load
Floor
- bedding +/-
- straw bedding: good foot holding, soft, good thermal properties, water absorption
- resting area
- handling passages / dunging area: animals stay for short periods, not slippery, resistant to rodents/ mechanical cleaning/ chemicals
- removal: faeces, urine, microorganisms, gas, NH3, CO2, ventilation requires energy
- wet floor: animal don’t lie down, infection, heat loss
Resting area
- deep bedding: 20-25cm, refreshment daily, cattle/sheep/poultry
- superficial bedding: 5-10cm
- no bedding
- animals stay for long periods
Slatted floor
- cattle/sheep/pig/rabbit/poultry
- material: wood/ metal wire/ plastic rubber
- thermal attributes of slat materials should not be worse than the relevant value for the solid floor
- In poultry and rabbit operations slats should be made of light materials (welded mesh, plastic slats) to facilitate speedy warming up to body temperature
Demands for upper cover layer
- have about 3% slope towards dunging area
- water proof
- no cracks, good weight bearing
- capacity, resistance to strong water flush (cleaning), resistante to disinfectants
- warm, elastic, non-slippery, low germ content, easy cleaning, easy disinfection
Structural requirements of the floor
- cattle: proper cubicle size and settings, neck rail
- pigs: dirtying the same area, manure is important source of infection (E.coli, Ascaris suum), removal from the farm (150-200m)
Removal of faeces
- mechanical: automatic scraping with machines, no water added for less liquid manure
- hydraulic: high pressure water, slower flowing method
