A diagnostic tool kit to help maintain the health

of the sow and piglet






Maintaining the health of pigs is a primary job of the health team.  The health team includes the veterinarian, stockperson, manager and owner of the farm.  It also needs to include nutritionists, geneticists and other production advisors.  However, on many farms the health of the pigs is compromised because the environment is substandard.  It is therefore a requirement that the health team use a set of tools to quantify the environment.  This paper illustrates some of the equipment and its use, which may be employed to ensure that the environment of the pig maximizes its health opportunities.


Environmental analysis of the farrowing area


To protect the health of the pigs in the farrowing area a whole farm approach is needed starting with biosecurity and pig flow models.  It is assumed that these are already in place, together with adequate medicine protocols.  This paper will concentrate on the four key environment areas: water, food, floor and the air/ventilation system.




The water supply is analyzed by the use of five pieces of equipment:

1)         Adjustable wrench/spanner

2)                  Measuring tape

3)                  Screw driver

4)                  Stop watch

5)                  Plastic measuring cylinder


Source: - discuss with the producer the source of the water and when the water quality was last checked


Drinkers: - Examine numerous drinkers, checking for:

Height, type of drinker, angle of drinker, flows from individual drinkers, variability of flow between drinkers and flow when a number of drinkers are in use. Discuss if additional water is added to the feed by hand.


Check the behavior of the pigs using the drinkers: - For example if the farrowing house is equipped with nose drinkers these are not intended to provide water to the sow but to the trough.  If there is a drainage hole (or rust hole), or the trough is full of feed, the sow’s water supply can be severely restricted.




The feeding system is analyzed by the use of five pieces of equipment:


1)                  Measuring tape

2)                  Plastic bag (from the farm – arm length gloves are fine)

3)                  Screw driver – to cut into any mould found in the trough

4)                  Weight scale

5)                  Volume measure – food scoop

6)                  Feed sieve - Bygholm


Examine the feeder for

Evidence of waste feed, in particular under slats.  Particularly look at areas where creep feed is being feed.

The size of the feeder – some feeders can be too small to allow the sow to place her head properly into the feeder.

Examine for wear in the feeder – holes allowing waste feed to escape or rough edges that might injure pigs.

Amount of feed being fed and type of feed being fed.  A major responsibility of the stockpeople is to ensure that the lactating sow eat appropriately.

Content of the feed – for example dust and whole grains. Use a Bygholm sieve to estimate particle size of feed.

Smell or taste the feed – for mycotoxins.


Discuss feeder management and feed curves that are in place.


Collect a sample of feed (>250g) for further analysis if necessary.  If the sample is not going to be immediately examined, or needs to be kept for legal reasons, store the feed at –20ºC.


Look for the presence of mould

In particular examine the corners of the feeders.  Note the design of the feeder and areas where moldy feed may accumulate.  Mould may also occur in feed barrows, particularly if they have been outside in the rain.  If maggots are in the feed this can provide an indication when the rotting feed was last checked. Musca domestica eggs hatch in a minimum of 24 hours and become a pupae in a minimum of 7 days and flies hatch from the pupae in a minimum of 10 days.


Feed bin management

Check that feed bin tops and inspection hatches are closed at all times to prevent rain entering.  Check the inside of the feed bin for areas where feed is sticking to the edges or mould is clearly evident.


Feed storage

In particular look at bagged creep feed.  Bagged feed should be stored on pallets to reduce rodent infestation.  Bagged creep feed should be kept cool.


Floor and surfaces


The floor and surfaces are analyzed using four pieces of equipment


1)                  Ultrasonic distance measure

2)                  Measuring tape

3)                  Calculator

4)                  Voltmeter


Stocking rates and crate design

While in the farrowing area stocking rates are less significant that in finishing, the farrowing crates need to be adequate for the modern sow’s length and to provide comfort without risk of trauma to the piglets.  Ensure that the farrowing crate does not have rough edges. The area occupied by the piglet creep needs to be assessed.


Building size

Analysis of the building size not only provided information on its optimal occupancy, but also provided information on its ventilation requirements.


Floor surfaces

Floors should be smooth, but not slippy so as to prevent injury to the pigs and so designed as not to cause injury or suffering to pigs standing or lying on them.  The floor must be suitable for the size and weight of the pig and form a rigid, even and stable surface.  It is unfortunately common to find rough/sharp aggregate exposed particularly in the area of the drinkers and feeders.  With slatted systems check the integrity of the slats and their fittings.  Avoid holes where legs and feet can get stuck.


Edges of gates and walls

Projections can cause serious damage to pigs.  Pigs will rip off exposed metal lining gates and lick it into very sharp edges and points.



Ideally pens should not contain steps or slopes greater than 20º.  The examination should include the passage the sows make to the farrowing area and the piglets make to the nursery.


Stray voltage

Poorly earthed electrics can create current within buildings and can result in electrical discharge though the pigs.  This can affect intake of feed and water. Use a voltmeter to detect stray voltage where it is suspected.



Air and the ventilation system


The air is analyzed by the use of five pieces of equipment

1)                  Smoke tubes

2)                  Wind speed – anemometer

3)                  Temperature and relative humidity pen

4)                  Gas analysis tubes – carbon dioxide, carbon monoxide and ammonia

5)                  Voltmeter


Air flow direction


The easiest and quickest method to detect airflow is the back of the hand placed around potential air inlet points.  If the hand is slightly wetted, this increases its sensitivity.



There are a variety of smoke releasing equipment available commercially.  For use in a farrowing house small smoke sticks with liquid titanium chloride, which smokes on contact with the air, are ideal.  The method of use is to break the stick using a set of pliers.  The stick will smoke for 5 to 10 minutes.  Note the smoke is slightly warm and therefore will naturally rise.  A smoke stick is ideal to look for localized drafts in the region around the piglet.  A smoke stick can be put into the end of a long hollow tube to examine for drafts out of reach.  To examine the farrowing room, medium sized smoke bombs are used releasing 18m3 of smoke.


Smoke is ideal for the examination of low airflow and drafts.  Note that the smoke will rise in the locality of a heat source, such as a heat light.  Sow breaths and piglet movements may also cause apparent ‘drafts’.  The smoke sticks are best used in combination with a wind anemometer to determine both the direction and velocity of the air movement.


Care should be exercised when using smoke sticks and smoke bombs based on titanium chloride.  The titanium chloride when exposed to moisture, reacts to form smoke composed of titanium oxychloride, titanium oxides and hydrochloric acid.  While normally not hazardous in the small quantities produced in a smoke stick, these compounds are corrosive and acidic.  Store the smoke sticks in a sturdy box in a place safe from accidental crushing.  Avoid inhaling the smoke.  Read all the instructions with the equipment before use.


Wind speed

There are numerous wind speed measuring devices, many are very expensive.  Cheaper vane anemeters only measure horizontal airflow and can only be used in combination with smoke to demonstrate the direction of the airflow to be measured, however, are still useful in a clinical setting.  A draft in the farrowing house is air speeds in excess of 0.2m/s.


Temperature and humidity

There are a number of cheap temperature and humidity pens available.  Note it is best that the equipment is switched on and left on a suitable ledge inside the building for five minutes to stabilized the temperature of the equipment.  Note your car boot can be cold, hot and/or damp, and this will affect the immediate response of the instrument. 

The investigation in each building should

a)                  record the external temperature and humidity

b)                  record the temperature and humidity at the inlets (this should equate to the external temperatures).  This is recorded as the minimum temperature

c)                  Record the temperature and humidity 0.5 metres before the outlet

d)                 Take various intermediate recordings around the room at pig height

e)                  Place the thermometer close to the temperature probe and compare the reading from your temperature pen and the reading at either the room controller and/or the max/min thermometer


When examining the room set up, look at the max/min thermometer in detail, checking for air bubbles, mercury about the floats, broken mercury lines and moveable mercury U bends.  If the thermometer is found to be defective, it must be replaced.



Check fans for:

a)      Excessive noise when working

b)      Variable speed fans – check speeds are functioning by holding the temperature probe inside the house and noting the fan’s response.  This may need to be avoided on very cold days

c)      Stop the fan – do not use your finger to slow the fan down.  Examine the fan blades in detail for areas of dust, corrosion and areas of missing paint

d)     Measure the size of the fan and record the fan speed using a tachometer


Once the fan’s speed has been calculated using a tachometer (not included in the simple kit) routine checking of the fan can be accomplished with a voltmeter.


Alarms and fan fail safe equipment

Check that the alarms work by holding the alarm probe and note the temperature settings.  Check fail-safe systems come into operation when required.  Note replace all fail safe equipment before leaving the building.



Examine all inlets for obstructions such as weeds at the edge of the building.  Note the position of the inlets and pattern of airflow through the inlet.


Inlet management can be very poor with inlets being stuck open or shut. Variable inlets around the house result in variable ventilation to the pigs.


Open doors can significantly alter the ventilation system and are a major source of drafts.



Dust is difficult to estimate. Dust comes in two major forms, non-respirable and respirable.

a)      non-respirable dust

Non-respirable dust easily settles out and this dust is commonly seen throughout all housing systems. This dust is important as it irritates the nasal and upper respiratory tract, however, this dust is unlikely to enter the lung tissues.

b)      Respirable dust

Respirable dust is less than 3 mm and may enter the lung tissues.  They are therefore particularly important in respiratory disease, especially if these dust particles are coated with bacteria and/or viruses.  Note if the particles are less than 1.6 mm they will not settle in the lung tissues but will blow in and out.


Unfortunately respirable dust particles are not readily visible to the naked eye.  They can, however, be visualized by three methods:


1)      Respirable dust in large quantities make it difficult to clearly see the far wall of the building, particularly in buildings over 30 m long

2)      Respirable dust can be seen as a shaft of sunlight when the light enters the building

3)      Respirable dust can be illustrated using a strong halogen light source.


Air quality

Gas pollutants can be easily measured using gas concentration sticks.  Examine for Carbon dioxide (building ability of cope with animal respiration)

Carbon monoxide (buildings ability to cope with burning heat source – gas heaters)

Ammonia (building’s ability to cope with the pig slurry and urine)


Carbon dioxide and carbon monoxide are odorless and therefore a gas concentration stick is necessary.  Ammonia, above 5 ppm will be smelt, at 10 ppm some mild eye irritation is noticed and above 15 ppm tear flow and significant eye irritation will be felt.


Hydrogen sulfide concentrations may be examined.  Note this is odorless at fatal concentrations, below this it has the characteristic rotten egg smell.


If there is a problem with gases in the room, it is not uncommon for stockpeople and advisers to complain of head aches.



The light availability is measure in lux units.  In general a stockperson can easily examine animals at greater than 50 lux.  Pigs must not be kept in permanent darkness.

Check that all the lights are working and the light coverings are clean.


Lying patterns

Quiet careful observation of the sow and piglet’s lying patterns will often alert the observer to potential problems.  Cold pigs are huddled and will pile in particular areas.  Their legs are tucked under their bodies to reduce heat loss.  Heat stressed pigs will pant and lie in wet/soiled areas, generally resulting in dirty pens and dirty pigs.  Examine the cooling systems for evidence of blockage and poor drip controllers.

A Simple Pig Environment Analysis Kit


Would consist of the following basic pieces of equipment –this will cost less than $500

1)         Adjustable wrench/spanner

2)                  Measuring tape

3)                  Screw driver

4)                  Stop watch

5)                  Plastic measuring cylinder

6)                  Weight scale

7)                  Ultrasonic distance measure

8)                  Calculator

9)                  Voltmeter

10)              Smoke tubes

11)              Pliers

12)              Wind speed – anemometer

13)              Temperature and relative humidity pen

14)              Gas analysis tubes – carbon dioxide, carbon monoxide and ammonia




A guide to some parameters related to maintaining the health

of the lactating sow and her piglets



The drinker should be 76-91cm from the ground to the sow’s nipple drinker. 

Piglet nipple drinkers should be 10 cm from the ground.

The drinker should provide a minimum of 2 litres per minute for the sow and 300 ml per minute for the piglet.



The sow should be eating 10 kg per day of a lactating ration of 18% protein 1% lysine and 14.5 MJ diet on day 18 of lactation.  Following a typical lactation feeding curve this will provide an average intake of 6.3 kg per day for a 21-day lactation.



Suggested length of farrowing crate:

Sow Weight kg

 Length cm









The crossbar at the top of the crate should be a minimum of 150 mm above the back of the sow when standing in the normal position

The escape area around a farrowing crate should be at least 30 cm wide.

Together with side creeps the width of the farrowing area should be a minimum of 1.7 m

The heat mat should be a minimum of 0.6m2

An outdoor farrowing arc should have a minimum floor area of 4.5m2



No air movement over 0.2m/s at piglet height

Ambient air temperature for the sow 16ºC to farrowing.  20ºC at farrowing then 16ºC two days after farrowing. 

Cooling systems need to be used when air temperatures are above 24ºC

Piglets ambient air during sleeping 30ºC. Infrared measurement of heat mat 36-42ºC.

Relative humidity between 50 and 75% RH

Ammonia concentration less than 5 ppm.

Carbon dioxide concentration less than 5000 ppm. 

Carbon monoxide concentration less than 50 ppm

Dust less than10 mg/m3

Light greater than 50 lux



Using this system similar guides for all areas of pig production can be produced.