Breeding and reproductive performance are important factors of any successful pig unit.

Achieving a consistent flow of sows and litters through the unit is paramount to the smooth operation of a pig farm.

As we know, breeding key performance indicators (KPIs) can be notorious for seasonal fluctuations and it is not uncommon for units to go through periods of excellent performance, followed by periods of below-average performance.

Tracking your breeding herd performance by actively and continuously examining your performance reports helps you to identify where and how to concentrate your time, effort and investment to improve efficiencies and reduce the cost of production.

Empty days or non-productive days (NPD) can be biologically defined as “any day a sow or gilt of breeding age is present in the herd and is not either gestating or lactating”.

The empty day calculation is taking the cycle from start to finish rather than certain aspects in isolation.

Therefore, empty days should be considered as one of the most important influences on breeding herd efficiency as they can directly affect unit profitability due to their influence on the volume of pigmeat sold.

If overall output is reduced, the pigmeat sale volume will decrease and therefore the overhead cost per pig will increase. Therefore, it is imperative to pay particular attention to the number of empty days. Current statistics reveal that the average number of empty days per litter stands at 15. surpassing the ideal target of 10 to 12.

In financial terms, there is a direct cost associated with empty days.

This is currently calculated at €2.96 per day (at the time of writing) and it is based on the direct cost of keeping extra sows in the herd including the extra feed, housing, healthcare, and all other costs associated with keeping non-productive sows.

Lost revenue

Moreover, this can translate into lost revenue, as farms miss the potential of more pig sales each year due to fewer productive days.

Accurate recordkeeping

Accurate individual identification of sows and sow groups allows you to concentrate on these pens at 21 and 42 days post service. Some of the information you need to record on your service record card includes sow number, date weaned, date served and expected farrow date.

Any other observations (eg bleeding and previous abortions). Consider investing in a recording system that allows you to dive deeper into your breeding performance and generating and studying these reports regularly can help to identify any issue early on.

Gilt condition

Are you optimising the performance of your gilts? Are you using a gilt-rearer diet as opposed to a finisher ration? Have all gilts presenting at service at a minimum of 33 to 34 weeks of age but not over 38 weeks.

Have a backfat cover of 14mm to 15mm. Make body condition scoring part of your breeding protocol. Finetune your synchronisation methods to improve your services.

AI storage and handling

Storage temperature should be within the range of 15°C to 19°C. Semen is extremely temperature-sensitive and shelf life is significantly shortened above 19°C.

Store semen doses horizontally, not in an upright position and rotate packs twice daily. This ensures maximum contact between sperm and the diluent in which it is preserved, which maintains nutrient availability to the sperm, and is important to protect semen viability and maximise shelf life.

Observation throughout gestation

Attention to service must include ensuring that mating is successful and occurs at the correct time, that semen quality is adequate and that no post-mating discharges occur.

Carefully observe sows from days 14 to 15 after service for signs of slight discharge or sticky mucus and identify or highlight any sows in which this is seen as they are likely to return. Walk a teaser boar through the dry sow house daily to check for served females on-heat/repeating, concentrating in particular on served gilt pens and groups three and six weeks post service.

Pregnancy testing

Early and accurate identification of pregnant and non-pregnant sows and gilts in combination with accurate individual sow recording can allow earlier identification of repeats or abortions, which will help to improve reproductive efficiency in your herd.

Repeats and abortions

Ideally, less than 10% to 12% of sows/gilts served should be repeats, with less than 5% being due to failure in detection. A high level of repeats may be associated with urogenital tract infection in sows seen as discharge about two weeks after service.

Problems with a high level of repeats should be considered in conjunction with the assessment of sow condition at different stages, but especially at weaning.

With abortions there are numerous reasons why a sow may abort but some of the most common are caused by disease, injury and environmental stress.

Lameness and pain, particularly from abscesses in the feet, or leg weakness can also cause abortions due to stress. Sow mortality in late pregnancy has major implications on empty days as the entirety of her pregnancy will be classed as empty days because no litter was produced.

Lighting

Low lighting will trigger a higher level of repeats and abortions at any time, but especially in the autumn as the pineal gland (light sensor) within the sow’s brain has an effect on the progesterone hormone. Lighting in female pig housing should be at 300 lux.

Maintaining a viable pregnancy requires constant daylight length. Ideally, this should be 12 to 16 hours per day, beginning at 6am.

It is important that the covers of the lights are regularly cleaned (every six months) as dirty covers can reduce the effective light intensity by 50%.

Temperature

Wet, damp environments or high air movement cause chilling and increase demands for energy. Ensure that the service house is dry and warm (210C to 220C). Use a min/max to assess the room temperature at night.

Remember that if the tank is deep and empty, which may cause under-slat air drafts, this will not be picked up by the min/max thermometer.

On a windy day, do a smoke test over some of the slats to see if there is an upward draft from the tank.

Aggression

Aggression between unfamiliar pigs is a natural behaviour and will establish and maintain dominance in relationships.

However, during the formation of the new social groups aggression can be intense and may result in stress and injuries (lameness). High levels of aggression may occur when mixing your sows in the dry sow house and can negatively affect your NPDs.

Only move sows and gilts within two days or after 28 days post-service.

Ensuring that the sows have feed in the trough on entry into the dry sow house may reduce the level of aggression.

To help identify if aggression after mixing is having a negative impact, pregnancy scan to assess the effect of fighting/mixing – ideally at feeding time to make the job easier.

While the days involved in gestation and lactation are effectively fixed, the key to increasing your efficiency is to improve your NPDs and management plays a vital role in doing this.

Minimising NPDs is therefore one of the most important aspects of sow management after breeding.

Reducing empty days is essential not only for cutting costs but also for boosting overall productivity.

Implementing effective strategies to address this issue can have a significant impact on farm performance.