The Calf's Environment
Regardless of the type and
age of cattle or type of housing (cubicles, straw yards, pens or
hutches) the accommodation must provide for the animal's most basic
needs if animal performance is to be maximised and welfare
standards met. Air space is just as crucial as floor area.
Pneumonia is especially common in housed animals and the disease
can often be avoided if buildings are not overcrowded, are well
ventilated and well drained, and animals of different age groups
are not mixed together.
With dairy units it is not
uncommon for young stock to be housed in cubicles, although straw
yards are more common in beef units. There are advantages and
disadvantages with both housing systems, but if the adult cow is
being housed in cubicles then there may be advantages to housing
the heifer replacements in suitably sized cubicles.
Regardless of regulations or
quality assurance schemes, calves require a clean, dry bed in well
ventilated but draught free (<2m/sec) conditions. They can be
housed individually or in groups. Calf pens should be large enough
to allow calves to groom themselves, lie down and stretch their
limbs and rise without any difficulty and must allow visual and
tactile contact with animals in adjoining pens/hutches. Therefore
pen divisions must be perforated, i.e. allow calves to see and
touch one another. Not to do so may have cross-compliance
reverberations as this is a requirement of legislation! Calves must
be group housed from 8 weeks of age, unless an animal is kept in
isolation on the advice of the veterinary surgeon.
Whether they are
housed individually or in groups calves require a clean, dry bed in
well ventilated but draught free
The width of the individual
stall/pen for a calf from birth to 8 weeks of age must be at least
equal to the height of the calf at the withers, as measured in the
standing position. The length shall be at least equal to 'the body
length of the calf, measured from the tip of the nose to the caudal
edge of the pin bone' multiplied by 1.1. In practice this means
pens at least 1.5 x 0.75m, but preferably 1.8 x 1.0m.
Fig 2: Calf pens
should be large enough to allow calves to groom themselves, lie
down and stretch their limbs and rise without any
1: Space allowances for group housed
Mass of calf
No more than 12 calves are
recommended in any one group; sick calves can be easily identified
and treated when they are in small groups. There should be no more
than 30 calves sharing the same air space and they should not share
that space with older cattle. Air space is critical; with a minimum
of 6m3 air space per calf at birth which increases
10m3 by 2 months
of age and then at least 15m3 by 6-7 months. The greater
the number of calves in a single air space, the greater is the risk
to health. A calf with respiratory disease can shed millions of
infectious organisms from its lungs into the atmosphere.
Calf hutches provide suitable
housing for either individual calves or the larger hutches can
accommodate up to 5 calves. Each hutch must have an outside run for
the calves to move around and be in fresh air. The hutches should
be situated on either free draining concrete or on a porous (e.g.
chalk) base ensuring that any effluent goes to a suitable site for
disposal. Plenty of clean, dry bedding (normally straw) needs to be
provided which should be disposed of after each batch of calves.
Ideally the hutches should be moved after each batch of calves to
minimise disease risks.
Fig 3: Calf
hutches can be individual or multiple accommodating up to 5
Cattle are homeothermic
animals and need to maintain a constant body temperature of around
38º C. The Lower Critical Temperature (LCT) is the temperature
below which an animal must burn extra energy to keep warm, i.e.
feed is channelled away from growth/production to keeping warm. At
temperatures above the Upper Critical Temperature (UCT), cattle
will sweat in an attempt to dispel the excess heat and the animal
will become heat stressed, which can lead to death of the animal.
As cattle sweat at only 10% of the human rate they are much more
susceptible to heat stress.
The body temperature can be
affected by air temperature, radiant temperature, wind speed and
relative humidity together with animal factors such as size of
animal, coat thickness, feed level and type, body condition, etc. A
newborn calf needs to be kept in a temperature of no less than 7ºC
if it is not to suffer. By one month of age a calf can comfortably
withstand temperatures around freezing point. It is important
though that calves are kept out of draughts, as this decreases the
LCT quite considerably. However, rarely are low temperatures a
problem in UK conditions with housed animals, quite the converse
with the main issue relating to high temperatures and humidity
within a building.
At grazing, the story is
different due to the compounding effects of rain and wind. Rain in
particular can lead to serious mortality rates at grazing, if some
form of protection is not offered to young calves. With the calf at
its LCT, just 0.10inch rain can increase calf mortality by 2-4%.
The rates are even higher in calves that have not received adequate
amounts of colostrum.
Dust and gas can have adverse
affects on the health of the calf and young animal which extend
through to lactation and slaughter. Not only does dust irritate the
respiratory tract and mucous membranes it leads to permanent damage
to the lungs and encourages micro-organisms. Ammonia at levels of
25ppm will irritate the mucous membranes and also make the animal
more vulnerable to respiratory diseases. Studies show that ammonia
levels in the first 4 months of life severely impact on the age at
first calving. Although carbon dioxide is not poisonous at levels
above 3000ppm it adversely affects cattle due to less oxygen being
present. Hydrogen sulphide is highly toxic with levels above 50ppm
known to kill cattle - the main cause of this problem being
agitation to below ground slurry stores.
Fig 4: Adequate
ventilation is essential to reduce noxious gases and
Not only is air space
critical but so is the ventilation rate, which is the amount of air
replaced within a building in a given time. The aim is a minimum
air change within a building of 10 times each hour, increasing in
the summer up to around 60 air changes per hour. The purpose is to
keep the air fresh. Studies from the USA show that higher humidity
and mean temperatures within the calf housing results in a delayed
first calving. It is probable that this would also appear as slower
live weight gains in fattening cattle.
In the housed environment a
constant supply of fresh air is essential in preventing respiratory
and other diseases together with improving production. Good
ventilation removes stale, damp air which helps ensure that viruses
and bacteria cannot survive for long outside the animal.
Ventilation should never be restricted in an attempt to raise air
temperature. In the vast majority of situations natural ventilation
is adequate. However, if artificial (fan) ventilation is required
then it must only be controlled manually or by humidity sensors,
never by a thermostat.
Almost all infection occurs
by direct aerosol spread between calves, so it is vital that there
is good ventilation to allow for removal of infectious organisms.
Similarly an increase in humidity will favour viral/bacterial
With climate change a real
issue and the increased risk of heat stress in all ages of cattle
consideration will need to be given to the installation of fans,
with our without tunnels, combined with spraying water onto the
cattle. This can dramatically reduce the effects of heat
Natural ventilation is the
most efficient and least expensive system for providing an optimum
environment within a building. The objective of the ventilation
system must be to provide a continuous stream of fresh air to every
housed animal at all times of the day or night. Buildings will
naturally ventilate best when they are sited at right angles to the
prevailing wind direction. In the UK the prevailing wind is
generally from the south-west but is influenced by local
To ensure adequate
ventilation, it is important that the building is designed
excess water vapour;
micro-organisms, dust and gases;
a uniform distribution of air;
correct air speed for stock.
In the UK, wind speed is
above 1m/sec for more than 95% of the time. This means that for the
majority of time, there is sufficient generating force to provide
the necessary air changes within a correctly designed building by
natural ventilation. For the remaining time, the building relies on
the stack effect to replace foul air with fresh air.
Heat produced by the
livestock naturally rises. If it is unable to escape from the
building at the highest point (at the ridge), it will condense and
remain within the building raising the humidity levels. As the air
cools, it will fall back onto the bedding, increasing the moisture
content and creating a suitable environment for bacteria to
flourish. At a relative humidity above 75% pathogens and viruses
can survive for several minutes which increase their spread from
animals to animal. However at RH levels below 75% viruses die very
quickly after exhalation. With many calf houses the humidity is
such that viruses can survive for around 40 minutes creating a
reservoir of infection in the air which means the disease is
Fig 5: Natural
ventilation by the stack effect
Natural ventilation requires
the right balance of inlets and outlets. If the warm air is able to
exhaust from the ridge of the building, this draws fresh air into
the building through the side inlets. This air change ensures the
stack effect is maintained. The inlet and outlet areas should be
about 0.05m² and 0.04m² per calf respectively, with the outlet
being at least 1.5m above the ventilation inlet.
The pitch of the roof can
influence how well the stack effect is established. A roof profile
of 1:4 and 1:3 are ideal. However, the pitch of a roof will always
be a compromise between ventilation and overall ridge height,
especially with span buildings. It is essential that there are
adequate outlets in the ridge of the building. An open ridge is
generally between 0.3-0.4m wide and should be un-restricted. As a
useful rule of thumb, there should be 5cm of ridge opening for
every 3.0m of building width. Although cranked open ridges are
still commonly fitted, they only offer around 20% of the required
The design of a successful
natural ventilation system is complex and requires account to be
taken of the span of the building, the location of the building
relative to other buildings or obstructions (buildings and trees
disrupt airflows for a distance of 5-10 times their height), the
pitch of the roof, the stocking rate, mass of each animal and the
During the main/conventional
housing period mechanical ventilation may be required in some calf
buildings due to design constraints but should be the last option.
However, with summer housed animals this may be essential to
minimise the effects of heat stress.
During the summer months fans
assist air movement to provide a cooling effect and so increase
heat loss from animals.
There are relatively few
buildings, which cannot be made to ventilate naturally if they are
designed carefully, or remedial works undertaken. The decision to
resort to assisted ventilation, with the resulting running costs
and maintenance should not be taken lightly. In addition, where
mechanical ventilation is essential then fail-safe systems and
alarms are a necessity.
The quality of cereal straw
varies from year to year, but with alternative uses its price is
also becoming a serious issue - even in the cereal growing areas of
the country. Efficient use of bedding is therefore of the essence
but care must be taken to ensure that cattle cleanliness and
welfare are not compromised.
Other bedding materials
include sand, sawdust/shavings, bark peelings, waste paper and
gypsum waste. Studies of various materials by the University of
Arkansas found no significant differences in output of calves
housed over a 6 week period on different materials, although straw
and wood shavings provided more warmth and absorbency compared to
products like sand. However, no cleaning out of pens was done in
the trial period which would be uncommon in practice on sand based
systems. Recycled manure solids must not be used to bed
calves, i.e. cattle less than 6 months of age It can only be
used in cubicles and not for deep bedded yards for older
Design of Lying Areas
These should be rectangular
in shape with a scraped concrete feed/loafing passage. This
concrete helps promote hoof wear and will prevent feet becoming
over-grown. Aim for a passage width of 2m for animals less than a
year of age, which should be scraped regularly at least 3 times per
Where the yard is for both
suckler cow and calf then the bedded area needs to be a minimum of
6.0m2 with a loafing area of at least 2.5m2.
This will mean the scraped passage needs to be at least 3.5m wide.
This allows cows to feed at the manger, with other animals moving
around behind them. A step should be provided between the
feeding/loafing area and the straw beds. This will help retain the
straw and prevent manure flowing onto the bedded area, although
unlikely with the type of ration that suckler cows are offered.
However, on a practical note a solid barrier provides a straight
edge to scrape against when cleaning out the loafing area. The
height of the barrier will depend on the frequency in which the
beds are cleaned out, but it is likely to be around 0.2m. The
barrier height should not exceed 0.3m.
In addition a creep feed area
should be allowed for the calves and the area should match that
given in Table 1.
Cubicles must provide a clean
comfortable lying space for the heifer calf. Cubicles are not
suitable for bull calves as they urinate in the middle of the
cubicle base. The calf/yearling must be able to enter and leave the
cubicle easily and lie down and rise without interference or
injury. Poorly designed cubicles and inappropriate management can
lead to problems such as cubicle rejection through to adult life,
wet and soiled cubicle beds and physical injury to the
Fig 6: Well
designed cubicles can provide suitable conditions for heifer calf
The length of the cubicle
needs to be adequate to allow the heifer to rest comfortably and
rise without injury. The position of the animal when lying down and
standing are controlled by brisket boards and headrails. A
correctly positioned heifer calf means that urine and dung fall
into the scraped passage and not on to the cubicle base.
There needs to be sufficient
distance between cubicle divisions to allow the calf/yearling to
lie comfortably while ensuring she is unable to turn around. She
should not come into contact with the cubicle partition in such a
way that could cause injury, be it when she lies down or rises.
When an animal rises from a lying position, it lunges forward to
transfer its weight from the hindquarters onto the forequarters. To
accommodate this transfer of weight, the animal thrusts the head
forward and this lunging space must be designed in the cubicle. If
the forward lunging space is restricted then difficulty in rising
will be experienced.
Cubicles need to be designed
for the size of animal at the end of the housing period.
Cubicle Length - The
total length of the cubicle should provide body space, head space
and lunging space. Cubicle length is very dependent on size of
animal. It is better to have a cubicle too long as the effective
length can always be reduced. As a guide for calves (0-6 months)
the cubicle should be 1.56m long increasing to 2.0m for animals up
to 12 month of age.
Cubicle width -
Cubicle width must allow the animal to rise and lie easily. But if
the width is excessive, the animal will tend to lie at an angle in
the stall or turn around. The width of the cubicle will be
determined not only by the size of the animal but in part by the
choice of cubicle division. Slightly wider widths are required if
there is a rear support leg. For calves the width will be around
0.60m increasing to 0.82m for animals up to 12 month of
Division design -
There are many types of cubicle division on the market. Whatever
the type they must provide the animal with maximum comfort, provide
security/protection, prevent injury and ensure that she is
correctly positioned both standing and lying. The space sharing
division, such as the suspended cantilever type offer more room
allowing slightly narrower widths.
The main benefit of the
suspended cantilever division is that both height and width spacing
can be altered at any time. This provides flexibility, especially
where animals are growing rapidly.
As with dairy and suckler
cows there should always be at least 5% more cubicles than animals
within a calf management group. Overcrowding leads to reduced lying
times and increased lameness which is carried through to adult
life. There is also more bullying with an increased risk of
Space Allowance for
Although feed may be ad
lib and available 24 hours per day it has to be recognised
that there are peak periods for feeding during the day, e.g.
immediately after fresh feed is put down the trough. If there is
competition for feed space during this period, subordinate animals
will give way to dominant animals, modify their feeding behaviour
and their growth rates are likely to suffer. Feed trough space is
given in Table 2.
Table 2 - Feed face
required for cattle eating simultaneously.
Mass of animal
Width of feed face
Animals should be able to
pass behind those already feeding without disturbing them. This
means the passage should be at least 2m wide.
As cattle are herding animals
they are sociable in their behaviour. Adequate trough space or
water bowls must be provided to allow at least 10% of the group to
drink at anytime. The water trough should be located at the correct
height for the animal - again often a problem in practice with
rapidly growing animals.