HOUSING DESIGN OF DAIRY ANIMAL TO REDUCE STRESS UNDER INDIAN CONDITION
Dr.Chandrakiran Sant, Dairy Advisor,Pune.
India is a subtropical country, wherein the climate is of variable type. A shelter is required both in summer as we ll as in winter to counter the various vagaries of adverse climate and to provide a comfortable environment to the animals. The principle functions
of any system of housing for dairy cattle are:
(1)Provision of health sustaining and comfortable
environment to different categories of dairy cattle for
idea l productivity, health and longevity (2) Provision
of desirable working conditions for labour and
supervisory staff on the farm (3) Integration of
ho using with feeding, wa te ring, milk ing a nd manure
ha ndling systems.
Small and landless farmers that keep one or two
animals have limited income from them and do not
provide shelter for the animals. Ga wa li et al (2005)
repo rted that fa rme r sho uld provide housing utilizing
cheapest possible resources like wo oden logs, stra w,
tree lea ves combined with bamboo mat o r plastic
sheet. She lte r system should create a microenvironment inside animal sheds to provide pro te ctio n to anima ls aga inst stressful conditions.
Planning for shelter requirement for any region
should include agro -climate condition of region and
so cio e conomic conditio n o f its people . It sho uld be
co ndusive fo r expression o f its no rma l beha vio r.
The co nditio n inside the anima l houses in affe cted to a co nside rable ex tent by meteo rolo gical f ra ctio n of
external environment, the construction itself and
anima ls housed in them (Pa dmanabhamurthy, 1983). The max imum tempe ra ture inside the barns is invariably higher by 2oc than loose housing and open system in a ll seasons (Sa stry and Geo rge, 1985) Humidity, tho ugh higher in the loose house than in the open, is highest in the barn ho use .
Various Types Of Housing Systems Prevalent In India
Livestock may be successfully housed under a wide variety of conditions, ranging from closed confinement to little restriction ex cept a t milk ing time . Housing fo r ca ttle is commonly described as loose housing a nd conventiona l (o r sta nchion) barn system .
Loose Housing System: Loose housing is a rra nged
so tha t the animals can roam a t will within the
ho using a rea . Fo rage is usua lly pro vided in feed
mange rs a t a mo re o r less free cho ice basis,
depe nding upon the de tails o f the feeding
programme. Milk ing is do ne in a room designed
spe cifica lly fo r this purpose ca lled up m ilk pa rlour.
Shinde (1984) in a study of crossbred cows in loose
ho using obse rved tha t tempe ra ture and hum idity of environment significantly reduced milk yield.
Co rrela tion o f THI with m ilk yield pe r da y was
ne gative a nd highly significan t in a ll stages of
lactation. Korsun (1993) reported that milk yield of
co ws ke pt in shady co nditio ns we re significant in a ll
stage s o f la cta tion.
Conventional Barn System: Conve ntio nal ba rns
re fe rred to housing in which the co ws a re co nfined closed toge the r o n a pla tfo rm and se cured a t the ne ck by stanchio ns. Fee d is pro vided a t the
stanchions and the co ws a re milked the re . The
a tmosphe ric hum idity is highe r in ho t seaso n in loose
ho use than in she d. In co ld sea son the humidity is
simila r. The minim um tempe ra ture tested to be in
compa rison to ope n, consistently highe r by 1oc to
2.5oc in loose house , by 2oc to 5oc in shed. The
diffe re nce be tween inside and o utside va lue be ing fa r
highe r in coo le r sea son (P rasad 2004). The findings
indica ted that housing o f ca ttle in ho t hum id tropics
should be m inimal to allo w max imum ventilatio n and
air movement.
Importance Of Floor Space And Ventilation In Animal Housing
P ra ctica lly the re a re no sta nda rds fo r spa ce
requirement a nd spe cifica tions o f structures based on
experimental evidence designed to gauze animal com fo rt, o ptimum productio n a nd suitability to a spe cified management system . Ba sed on de libe ra tion among ex pe rie nced a nima l husbandry spe cia list, ra the r tha n o n empirica l findings the Bureau of Indian Sta nda rds (BIS) has brought out standa rds on spa ce requirements and construction de ta ils fo r ca ttle a nd buffa lo fa rms of diffe rent sizes.
Air movement and exchange (ventilation) is critical to
mainta in to co w com fo rt. Ventilatio n is a system of
air exchange to provide fresh air, temperature
There has always been a desire by dairy scientists, agricultural engineers, and producers to optimize the animal environment to allow animals to be as productive as possible. The challenge is to design the animal housing design with due consideration to animal health, feed cost, labor requirements, and the system’s environmental impact. To maximize profitability the costs of improving the animal’s environment must be realized by the benefits gained in improved animal productivity. The housing designs should be prepared in such a way, so that it improves the cow comfort during resting, and provide an environment where the cow can maximize heat loss during hot weather and minimize heat loss during cold weather. Choosing a particular housing system design is difficult because it is not always known how the system design will affect growth, health, and production of the animal.
Physical factors associated with housing facilities may have a greater influence on cow performance than climatic factors. Climate dictates what type of facilities is required for maximum production. The use of a cooling system or protection from winter conditions is determined by the location of the dairy. Since climate conditions vary widely, different facilities are required in different areas of the world. Choices made in housing designs may reduce or increase the effects of climate. Ultimately the housing designs play an important role in reducing the stress.
Stress on animals:
Stress is the body’s reaction to a change that requires a physical, mental or emotional adjustment or response. Excessive stresses due to a limitation in the animal’s environment will contribute to illness, compromise growth and the genetic potential of the animal. In facility design the goal is to minimize these stresses on the animal. Common stresses on animals are air quality (noxious Gases, airborne particles), thermal, transportation, vaccinations, changing rations, regrouping etc.
Various components of Housing Designs
Floor
The floors should be hard, impervious to water and easy to clean. The floors shall have a gradient of 1 in 40 to 1 in 60 towards the drains so that wash water can run into drains easily. The raised-slotted floor with thatched roof is best suited for growth, feed conversion efficiency and economic. Dairy cows always prefer soft floor, soft materials such as rubber mats and mattresses were suitable coverings and have shown good results. Ammonia emission from the compartment with the grooved solid floor operating with open perforations is reduced by 46% compared to the traditional slatted floor.
Roof
The roof should be light, strong, durable, weather proof, bad conductor of heat and free from tendency to condense moisture inside. The pitch of roof should be, 350 for thatched roof, 25 to 300 for tile roof and 12 to 180 for a sheet roof. The pitch should not exceed 450 at any circumstances.
Ranking of roof materials in terms of in house temperature reduction:
- Thatch 2. Clay tiles 3. Wood 4. Sun screen 5. RCC 6. Galvanized sheets
- Asbestos and 8. Plastic sheets.
Wall
For ordinary walls, thickness should not exceed 35 cm. Partition walls lining the open areas should be 22.5 cm (two brick) thick. Height of walls should be 2-2.5 m for houses with sloping roofs. When solid concrete walls are removed and replaced by steel piping, the roof is raised 1 m and outside paddocks is provided with palm thatch shelters, almost no trouble is experienced from climatic stress. It is necessary to cool cattle with a sprinkler during a particularly hot season, which was effective even with water temperatures of 350 C.
Insulating Materials:
The choice of an insulating material will depend on the application, availability and cost. Loose granular materials work best when installed above a ceiling or poured into existing wall cavities. Batting or blanket materials are easiest to install as walls are constructed. Rigid insulating boards may be placed under concrete floors or cemented to masonry walls. Reflective surfaces such as aluminium foil or paint are most effective when exposed and not in contact with other materials. They are also more effective in preventing the downward flow of heat and in relatively high temperature applications. Local natural materials such as straw, shavings, coffee hulls, etc., although not as high in resistance to heat flow as commercial insulations, may be the material of choice because of availability and low cost. A greater thickness will be required when using the natural materials and they may not be as fire and vermin resistant.
Table 1. Thermal Resistance of Pitched-Roof Spaces:-
Resistance (m² ° K/ W)
Direction of heat flow High emittance surfaces* Low emittance surfaces**
Ventilated Up Nil 0.34
roof space Down 0.46 1.36
Non-ventilated Up 0.18 0.56
roof space Down 0.28 1.09 - *dull, dark surfaces ** shiny, light surfaces
General Requirements for cow comfort
Sun Shade:
A shade structure allowing 2.5 to 3m: per animal will give the minimum desirable protection for cattle, whether it will be for one animal belonging to a small holder or many animals in a commercial herd. A 3x7m roof will provide adequate shade for up to X cows. 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. If the longitudinal axis is east and west, pan 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 as shown in Figure 1, 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 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.
A gable roof shade is shown in Figure. The gable roof is more wind resistant than a single pitch roof and allows for a center 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.Fig 1: Sun shadeYards:
If space is severely limited and only 4 to 5m² per cow is available, then concrete paving is highly desirable. If up to 40 to 60m² per cow is available, then unpaved yards should be quite satisfactory as long as the feed and shade areas are paved and the yard is graded for good drainage. A number of trees in the yard will provide sufficient shade.
Fig 2: Yard with fence line feed trough, paved feed area and earth mound
Free-stalls:–
Free-stall design must consider lying/standing space along with moving or dynamic space requirements of the cow. A solid front must not interfere with the cow lunging forward. The brisket board positions the cow correctly in the stall, thus keeping the rear of the stall cleaner. The stall width of 1.22 m is adequate for cow comfort and minimizing injuries. A lateral slope of three percent across the width encourages cows to lie in the same direction, again reducing the chance of udder and teat injury from adjacent cows. A longitudinal slope of two to six percent is suggested to encourage the cows to rest toward the rear of the stall. Another design consideration is the rear curb. With curbs of 20 to 30 cm in height, manure overflow from alley scraping is minimized. The partition for free-stalls is also an important design consideration.
Tie-Stall Sheds:-
Only in the case of purebred herds where considerable individual attention is given to cows can a tie-stall system be justified in tropical areas. 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. Stall partitions should be used at least between every second cow to prevent cows from trampling each other’s teats and to keep the cow standing straight so that the manure falls in the gutter.
Tie-Stall System Dimensions (metres):
Cow live weight
Stall Section 450 kg 550 kg 650 kg
Platform width 1.1 1.2 1.3
length 1.6 1.7 1.8
Manger width 0.5 0.6 0.65
Platform slope 2 – 4%
Stall Bed Alternatives:
The flooring material used for rest areas is very important for cow comfort. Free-stall surfaces had a profound effect on resting times.
Fabric covered “mattress” stall bed:
This type of stall bed is gaining popularity especially in concrete free-stalls. The mattresses are made of a tough interwoven material and sewn into longitudinal segments. The segments are filled with an inert rubber material such as ground rubber (Figure 3). The individual mattresses, one per stall, are covered with one continuous top sheet. The material is very resilient and appears to distribute the load, especially from bony protrusions, uniformly into the mattress. Usually a thin layer of dry bedding is spread over the fabric on a weekly basis to absorb moisture and reduce soiling. Bedding can consist of long straw, chopped straw, or kiln dried sawdust or shavings.
A commercially available mattress
Earth freestall bed:
An earth bed provides some cushion for cows resting in stalls and provides good footing during access to the stall. An earthen free-stall requires a significant amount of bedding for cow comfort. A disadvantage of this system is the maintenance of the bed level. Mechanical freestall levellers are not readily available.
Sand Bed:
Clean sand provides an excellent bed for free-stalls as it moves readily because it is cohesionless. Growth of bacteria causing environmental mastitis is minimal as well. Sand that does work into the alley provides good traction for the cattle. Quality of sand is very important as high clay content will create mud when it comes in contact with moisture.
Cow Comfort and Floor Design
Skid-resistant walking surfaces reduce injuries, and enhance estrus detection. Grooved floors are superior to smooth surfaces. Figure 4 shows how a hexagonal pattern of grooves improve skid resistance over a parallel pattern of grooves. Cows have been reported to walk from 180 to 2500 m per day in confined housing, thus they are at a great risk of injury from smooth floors.
Hexagonal vs parallel grooved patterns in a floor surface
Cow Comfort and Ventilation
A proper ventilation system must be designed to avoid high humidity and drafts during the winter, and high temperatures and stagnant air during the summer. An acceptable air quality in terms of respirable dust, ammonia, manure gases, and disease organisms should be maintained throughout the animal space. Ventilation or air exchange can be provided naturally or mechanically. Naturally ventilated barns can either be “warm” or have a “modified environment”. High relative humidities are observed in the modified environment barns. High humidity causes straw to pick up moisture at a faster rate thus resulting in more bedding maintenance. Equipment deterioration also occurs at a high humidity.
Naturally ventilated warm vs modified environment barns
Warm barn Modified environment barn
Natural/Mechanical ventilation Natural ventilation, uninsulated curtains
Insulation Minimal insulation
Inside 10 C, Relative humidity 70% Inside 0-5 C, Relative humidity 90%
Thermostats for side curtain control must be located 3m from the outside walls to maintain acceptable temperature distribution throughout the building. Chimneys are now recommended rather than continuous ridge vents. They are cheaper to build, make the building more bird proof, and protect the metal truss connections from the ammonia and water vapor produced in the animal airspace. Variable speed ceiling mounted fans are very effective in mixing the animals’ airspace. During the winter, low air speeds should be maintained to minimize serious drafts; whereas during the summer high air speeds will facilitate cooling of the animals. Exhaust fans and planned air inlets are used to provide air exchange in mechanically ventilated systems. A minimum of 10 and 15 L/s/cow must be maintained at all times for a warm barn and a cold barn, respectively. Exhaust fans are normally evenly spaced on the leeward side of the building.
Cross section of naturally ventilated barn
Air inlet design is very important in maintaining a good distribution of fresh air into the animal airspace. Forced air recirculation is recommended for mechanically ventilated barns since the fresh air entering through the planned inlets usually does not have sufficient velocity to encourage good air mixing. Because of the low ventilation requirement during winter conditions, most inlet openings cannot be made small enough to achieve appropriate air speeds. Ceiling mounted fans or perforated recirculation ventilation tubes or ducts are effective in distributing fresh air throughout the barn. Properly designed ventilation and heating system will result in acceptable air quality and temperatures. This will reduce the exposure level of aerial contaminants to the cow and provide the cow with an acceptable rate of heat exchange between her body and the environment.
Several items should be considered when installing an air inlet to bring in fresh air in a mechanical ventilation system.
- Select fans to deliver the required air volume and then size the air inlets to maintain an operating static pressure of .04 to .06.
- Position air inlets to promote adequate mixing of cool incoming air with warm air before entering the animal space.
- Ensure that the building is tight and that there are no unplanned openings. This involves sealing all leaks around doors, windows and feed augers.
- Be sure there are no obstructions that can deflect incoming air directly onto livestock. Be sure that lights, feed augers, heaters, etc. are at least 10 feet from the air inlet. Provide a smooth ceiling that extends at least 18″ from the inlet opening.
- Maintain and clean inlets, louvers, fans and all other parts of the ventilation system to assure the system works properly.
Lighting
Lighting requirements must not be overlooked. Suggested lighting intensity for housing is 10 to 30 foot candles. Sixteen to eighteen hours of light is considered optimal as this photoperiod has been observed to increase feed intake and milk yield by 6 to 16%. Metal halide and high-pressure sodium lamps are popular energy efficient options for cold areas where they can be mounted 11 ft or higher. Fluorescent lamps with electronic ballasts can start at colder temperatures (down to 0 F). Incandescent, halogen, fluorescent and metal halide lamps have a higher color rendition index (CRI) than high-pressure sodium and mercury vapor lamps. Colors are truer when observed under lamps with higher CRI values. Mercury vapor lamps are not recommended.
Conclusion
Housing design is an iterative process involving give and take. Cow comfort and ventilation problems exist in many barns which lead to reduced efficiency, increased costs, and problems with cow health. The concepts relative to cow comfort and ventilation should lead to thinking of ways to improve conditions in the many different types of dairy barns. Dairy cow housing design must take cow comfort into consideration. A well designed barn that is spacious, well lit, enjoys good air quality, and has well designed resting areas is conducive to a stress-free environment where dairy cows can perform well. It also provides a good working environment for farm employees. An animal that has a comfortable resting area will be relieved of stress accumulating in their legs and feet. Also, the thermal well-being of the animal must not be overlooked. A dairy cow consuming a high level of feed and producing a high level of milk will need to dissipate over 1200W of heat energy on warm days, therefore shade and mechanically increasing air needs to be considered so that the heat output of the cow can be exchanged with her environment. Attention to detail is one of the keys to success in dairying. It is far easier to accomplish this goal in a pleasant working environment than an environment that is stressful to animals as well as barn workers.
Reference-On request
