General Housing Requirements
Dairy cattle will be more efficient in the production of milk and in reproduction if they are protected from extreme heat, and particularly from direct sunshine. This can be achieved through provision of shade in tropical and subtropical climates. If dairy cattle are confined, the area should be free of mud and manure in order to reduce hoof infection to a minimum. Concrete floors or pavements are ideal where the area per cow is limited. However, where ample space is available, an earth yard, properly sloped for good drainage is adequate.
Majority of dairy animals are kept by smallholder farmers under zero grazing or semi zero grazing systems. Below is a layout of a zero grazing unit five cows.
When constructing a shade structure, it should allow 2.5 to 3m per animal which will give the minimum desirable protection for cattle, whether it be for one animal belonging to a small holder or many animals in a commercial herd. The roof should be a minimum of 3m high to allow air movement. If financially feasible, all the area that will be shaded some time during the day should be paved with good quality concrete.
The size of this paved area depends on the orientation of the shade structure. If the longitudinal axis is east and west, part of the floor under the roof will be in shade all day. Extending the floor approximately one third its length on the east and on the west, a paved surface will provide for the shaded area at all times.
If the longitudinal axis is north and south, the paved area must be 3 times the roof area i.e. 1/3 to the east, 1/3 to the west and l/3 underneath.
In deciding which orientation to build, the following factors need be considered:
- With the east-west orientation the feed and water troughs can be under the shade which will allow the cows to eat and drink in shade at any time of the day. The shaded area, however, should be increased to 3 to 4m² per cow. By locating the feed and water in the shade, feed consumption will be encouraged, but also more manure will be dropped in the shaded area which in turn will lead to dirty cows.
- With the north-south orientation, the sun will strike every part of the floor area under and on either side of the roof at some time during the day. This will help to keep the floored area dry. A shaded area of 2.5 to 3m² per cow is adequate if feed and water troughs are placed away from the shaded area.
- If it is felt that paving is too costly, the north-south orientation is the best choice in order to keep the area as dry as possible.
- In regions where temperatures average 30°C or more for up to five hours per day during some period of the year, the east-west orientation is most beneficial.
The gable roof is more wind resistant than a single pitch roof and allows for a centre vent. A woven mat of local materials can be installed between the rafters and the corrugated iron roof to reduce radiation from the steel and lower temperatures just under the roof by 10°C or more.
In a deep-bedded system, straw, sawdust, shavings or other bedding material is periodically placed in the resting area so that a mixture of bedding and manure builds up in a thick layer. Although this increases the bulk of manure, it may be easier to handle than wet manure alone. This system is most practical when bedding is plentiful and cheap. By designing the building to be partially enclosed on the east and west, the shading characteristics can be improved. In as much as a well drained earth floor is quite adequate, such a building will compare favourably in cost with a shaded area which is paved.
Loose Housing with Free Stalls
Although simple yard and a shade or yard and bedded shed systems are entirely satisfactory in warm climates, particularly in semi-arid areas, some farmers may prefer a system with somewhat more protection. A loose housing yard and shed with free stalls will satisfy this need. Less bedding will be required and less manure will have to be removed.
Free stalls must be of the right size in order to keep the animals clean and to reduce injuries to a minimum. When stalls are too small, injuries to teats will increase and the cows may also tend to lie in other areas that are less clean than the stalls. If the stalls are too large, cows will get dirty from manure dropped in the stall and more labour will be expended in cleaning the shed area. A bar placed across the top of the free stalls will prevent the cow from moving too far forward in the stall for comfortable lying down movements, and it will encourage her to take a step backwards when standing so that manure is dropped outside the stall.
The bar must, however, not interfere with her normal lying and rising movements. The floor of the stall must be of a non-slippery material, such as soil. A good foothold is essential during rising and lying down movements to avoid injury. A 100mm ledge at the back edge of the free stall will prevent any bedding from being pulled out to the alley. The number of stalls should ordinarily correspond with the number of animals housed, except that in large herds (80 or more), only about 90% of the animals need to be accommodated at one time. Young stock may be held in yards with shade or in sheds with either free stalls or deep bedding.
The alley behind the free stalls (cubicles) must be wide enough to allow the cows smooth passage and the following minimum widths apply:
The tie and feed barrier construction must allow the cow free head movements while lying down as well as standing up, but should prevent her from stepping forward into the feed trough. Most types of yokes restrict the cow’s movements too much. A single neck nail, set about 1 m high and 0.2m in over the merger may bruise the cow’s neck when she pushes forward to reach the feed.
A bull pen should have a shaded resting area of 12 to 15m² and a large exercise area of 20 to 30m². The walls of the pen must be strong. Eight horizontal rails of minimum 100mm round timber or 50mm galvanised steel tubes to a total height of 1.5m and fixed to 200mm timber posts not more than 2m apart will be sufficient. The gate must be designed so that the bull cannot lift it off its hinges and there should be at least two exits where the herdsman can escape.
A service stall where the cow can be tethered prior to and during service is usually provided close to the bull pen.
It is desirable to pave the alley, but if that is not possible, the distance between the free stalls (cubicles) and the feed trough should be doubled or tripled.
A concrete pit or sloping slab in which to accumulate manure is essential. If the alley is paved, the pit can also collect urine. In fact, paving the alley not only saves space, but the value of the urine will help to pay for the paving.
The circular manure tank a volume of 10m³ will be adequate to store the manure produced during one month plus any rainfall collected in the alley. If more stalls are added the capacity of the tank will need to be increased or the interval between the emptying shortened.
A water tank to collect water from the roof can be very useful unless there is an abundant supply of water nearby.
Housing for the Medium to Large Scale Herds
For the farmer with up to 30 cows a yard with paved shade and feed area would be suitable. The yard and feeding area may alternatively be combined with an open sided barn designed for deep bedding or equipped with free stalls and where the herd consists of high yielding cows the milking shed may be equipped with a bucket milking machine. Some farmers with up to 30 cows may even consider using an open sided tie-stall shed.
In general a medium or large scale dairy unit may include the following facilities:
- Resting area for cows:
- Paved shade, or
- Deep bedding in an open sided barn, or
- Free-stalls in an open sided barn
- Exercise yard (paved or unpaved)
- Paved feed area:
- Fence line feed trough (shaded or unshaded), or
- Self-feeding from a silage clamp
- Milking Centre:
- Milking shed or parlour,
- Collecting yard (part of the exercise yard),
- Dairy including milk store
- Motor room
- Calving pen(s)
- Calf accommodation
- Young stock accommodation (yard with paved shade and feed area)
- Bulk feed store (hay and silage)
- Concentrate feed store
- Veterinary facilities:
- Diversion pen with Artificial Insemination stalls
- Isolation pen
- Waste stores:
- Slurry storage, or
- Separate storage of solids and effluents
- Office and staff facilities
Each of the parts of the dairy unit may be planned in many different ways to suit the production system and the chosen method of feeding. Some requirements and work routines to consider when the layout is planned are as follows:
- Movement of cattle for feeding, milking and perhaps to
- Movement of bulk feed from store to feeding area and concentrates from store to milking shed or
- Transfer of milk from milking shed or parlour to dairy and then off the farm. Clean and dirty activities, such as milk handling and waste disposal, should be separated as far as
- The diversion pen with Artificial Insemination stalls and any bull pen should be close to the milking centre as any symptoms of heat or illness are commonly discovered during milking and cows are easily separated from the rest of the herd while leaving the
- Easy and periodical cleaning of accommodation, yards, milking facilities and dairy, and transfer of the waste to storage and then to the fields.
- The movements of the herdsman. Minimum travel to move cows in or out of milking
- Provision for future expansion of the various parts of the