Housing Requirements

Housing Requirements

1. Good ventilation

   • damp - cold
     • may drop below lower critical temperature of calves
   • stack effect
     • warm air rises up and out
       • draws cold air in from sides
     • used to replace stale wet air with fresh air
       • roof ridge
         • size matters
       • wall slats
     • steeper roof ventilates better
   • cubic capacity
     • allows fresh cold air to come in above cattle level
     • reduces pathogen contamination challenge/meter squared
     • 10 m per calf <90kg
     • 13 m per head <150kg
     • 15m per >150kg
     • generally not an issue because built to suit machinery so tall buildings
   • Balancing Outlet and Inlet
     • inlet must be 4x outlet space
       • outlet 0.04 msq per calf
         • inlet 0.16 msq per calf
       • outlet 0.1 msq per cow
         • inlet 0.4 msq per cow
     • can be tested with smoke bombs
     • simple thing to fix and should be implemented when required

2. Calf Housing

   • healthy environment
     • good site: open and sunny away from other stock
     • limited stocking density
     • adequate ventilation
       • without drafts or damp
   • stress free
     • allow time to aclimatize in isolation
       • should be able to see each other
     • match sizes in 8 week+ groups
     • removed from unnecessary noise
   • dry lying area
     • must be maintained
     • slats around drinkers ideal
   • adequate space
     • comfortable for all to be lying down
     • able to move away from drafts
   • easy to work
     • machine accessable
     • convenient for feeding milk/milk replacer
   • planned correctly prevents redesign/fixes
   • essential for raising healthy and thriving calves

3. Symptoms

   • Moisture
     • too much
       • supports pathogen growth
       • absorbs energy
       • transmission mechanism
       • slippery floors
     • standing water
     • dirty cattle
     • wet floors where they could be dry
     • staining on underside of roof
     • unhealthy animals
   • Fresh Air
     • too little
       • increases airborn pathogen survival time
       • reduced oxygen concentrations
     • smell - ammonia, damp
     • dark corners
     • elevated/variable air temperature in areas
     • unhealthy animals
   • Air Speed
     • too much
       • excessive energy loss
     • avoid certain aeas
     • huddling
     • shaggy coat
     • low production/growth rates
     • too little
       • associated with lack of fresh air
     • avoid certain areas
     • smell
     • unhealthy animals

4. Solutions

   • Moisture
     • drainage
       • within or between pens
       • effective gutters and downpipes
     • manure management
     • air inlet:outlet ratio
     • concrete flooring
     • leaking fixtures?
   • Fresh Air
     • balance air inlet:outlet
   • Air Speed
     • protection to above animal height
     • small holes over big area
       • slatted walls
       • wall cladding

5. Assessing Housing

   • roof
     • sufficient outlet area?
       • 0.04 m3 per calf
       • 0.1 m3 per cow
     • good slope?
   • walls
     • sufficient inlet?
       • 2-4x the outlet area
     • above cow height?
     • large openings creating drafts?
   • cobwebs indicate poor air movement
   • floor
     • standing water or wet surfaces indicate poor moisture control
   • everything comes back to good ventilation