6 tips to avoid autumn infertility in pigs

Autumn has arrived, which means the days are getting shorter and temperatures are falling. For pigs, this can signal the onset of various issues that can have a detrimental impact on reproductive performance.

Below, Angela Cliff, knowledge exchange manager at AHDB Pork, highlights the key issues that affect performance and provides tips on how to minimise the influence of the changing season and maintain good fertility throughout autumn.

See also: Advice for controlling PRRS in pigs

1. Counter the reduction in day length

Pigs under lights in a shed

Photo supplied by AHDB Pork

Gestating sows and gilts need 16 hours of light a day and, since light intensity is decreasing, it’s important to make sure you are providing sufficient artificial light.

Set timers to provide lighting for 16 hours/day, repair broken lights, clean dirty fittings and consider painting walls white to reflect light.

The required light intensity is a topic of debate. The minimum level stated in the Defra Code of Recommendations is for lighting with an intensity of at least 40 lux to be provided (which is about the brightness required to read a newspaper).

However, anecdotally, advantages have been noted from providing increased levels of light, for example, 200 lux during gestation, with weaned sows benefiting from even stronger light (300–500 lux), right up until service.

Remember, when taking a light reading using a lux meter, make sure you take the reading at sow eye level.

2. Minimise temperature fluctuations

Sows on straw bedding

© FLPA/REX/Shutterstock

While days are still relatively warm, autumn nights can be very cold.

These temperature fluctuations can disrupt sows as they need to both lose and conserve heat during the course of 24 hours.

This can have a knock-on effect on sows’ reproductive cycle and maintenance of pregnancy and can be a particular problem for those weaned in poorer condition.

Check temperatures over a 24-hour period and allocate a daily feed allowance that will compensate for anticipated cold spells. Even if you are feeding a generous level for the first five weeks, check that all sows receiving their share.

It’s also a good idea to start increasing the amount of good-quality bedding provided and block drafts.

3. Check semen quality

A boar stands in a straw yard next to another pig

© Tim Scrivener

Boars can be at their least fertile during autumn, having probably experienced several instances where they have been challenged by high temperatures during the summer.

This is because boars can remain sub-fertile for at least eight weeks following a hot spell.

If you are using boars for natural service, consider supplementing with artificial insemination (AI) and if you’re using boars for DIY AI, spend more time examining their semen under a microscope to ensure sperm are of good quality.

If there are any issues, consider purchasing AI from a breeding company until the quality returns to the correct standard.

4. Monitor ration quality

Rations are poured from a bucket into a pen of pigs

© Tim Scrivener

Digestibility problems can occur when feeding new crops from the recent summer harvest to pigs. Monitor sows when introducing the new-crop rations and if you spot any problems, speak to your supplier or nutritionist.

The warm days and cool nights can also cause condensation to develop inside feed bins; this can lead to compacted, mouldy feed, which may contain mycotoxins.

Ensure you have a good bin hygiene protocol in place.

5. Control rodents 

A bait box for catching rats

© Jonathan Page

Rodents will be returning to the comfortable temperatures of farm buildings, looking for somewhere warm and dry.

But remember, they carry leptospirosis, which leads to reproductive failure.

Furthermore, they also spread salmonella and other diseases.

Assurance schemes require farmers to demonstrate they have effective rodent control programmes in place; a good recordkeeping system should demonstrate that suitable approaches are being undertaken in line with best practice.

Details on rodent control options can found on the AHDB website.

6. Carry out pregnancy diagnosis

A sow is tested for pregnancy

Picture supplied by AHDB Pork

If you have previously had problems with increased abortions and “not-in-pigs” (NIPs) during autumn, it may be worthwhile maintaining physical boar contact for at least 20 minutes each day during the first five weeks of gestation. This can help with the establishment of pregnancy.

In addition, check daily for returns with a boar as there is an increased risk of irregular and late returns at this time of year.

If you are not already doing so, consider introducing pregnancy diagnosis four and seven weeks post-service.

If boar contact is not possible after this period, be extra vigilant and continue visual checks from nine weeks onwards to identify any late NIPs.

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