Pig fertility uplift can come from simple changes to herd management

Simple changes to pig management can result in significant improvements in fertility on units struggling with reproduction.

Factors influencing pig fertility are many and varied and can be due to infectious or non-infectious causes, says pig vet Dr Alex Thomsett, of The George Veterinary Group.

Non-infectious causes are often those that producers have more influences over, and in many cases usually mean very simple changes, Dr Thomsett told farmers participating in a recent Farming Connect webinar.

“A few small tweaks to management or the approach to reproduction on-farm can easily change a fairly difficult situation into a much better picture without going through a whole heap of blood sampling,” she said.

Among these is temperature stress; although this is more commonly associated with heat, cold can be a factor too.

Sows can find it difficult to adapt to changes in temperature and it can lead to more returns of service, poor cycling and higher numbers of abortions.

In outdoor herds, ensure pigs have mud wallows to dissipate heat and, to protect from direct sunlight, create shaded areas.

“This can be done very simply, with a few poles and a length of gale break or similar material,” Dr Thomsett advised.

Changes in day length can result in seasonal infertility in the autumn.

As this affects gilts in particular, Dr Thomsett recommends selecting gilts that are early to go through puberty rather than those that are delayed.

Pigs need a minimum of 16 hours of daylight so ensure light exposure in housing is good – even cleaning whitewashed walls or lightbulbs can make a difference by better reflecting light at sow level on the back of the eye.

Light is more difficult to control in outdoor herds because this system is beholden to the time of the year and, for this reason, Dr Thomsett stressed that it was vital to get all the other issues around fertility working well, including nutrition.

Gilts need the right nutrition balance to prepare them to come into first service and to support them through the first service.

“Gilts and young females are still growing through their first pregnancy and it can often be forgotten that when a pig is lactating, her body is preparing for the next cycle,” said Dr Thomsett.

It is therefore important to ensure there is no significant loss of body condition as this can impact on the performance of the ovaries.

But avoid overfeeding during gestation as doing this can result in a sow losing her drive to eat during lactation.

In herds with longer lactation periods, Dr Thomsett suggests providing piglets with supplementary feeding to support the sow.

“Get a good nutrition plan and have minimal swings in weight during a sow’s life,” she said.

Minimise stress as this is one of the biggest causes of fertility issues, especially in the first month after the pig has been served.

“Try to keep stable sow groups and avoid introducing new sows at this time,” said Dr Thomsett.

Management around service itself can have an enormous impact on fertility too.

If using AI, semen should be stored at between 16-18C° and turned a couple of times a day to ensure it is correctly suspended in its nutrient medium.

In systems that use natural service, MOT boars before service, ensure foot health is good and that all vaccinations are up to date.

Mycotoxicosis is another consideration and can significantly interfere with herd fertility but Dr Thomsett said this is an unlikely cause if the farm has good quality sources of grain and straw.

Adding binders to feed is the best form of defence because these absorb harmful mycotoxins.

Vaccinations are an important tool for preventing infectious causes of infertility.

These should be administered at the correct time – for instance, for Parvovirus no less than three weeks before service date.

“Use vaccinations in advance of service to get the maximum beneficial effect from them,” said Dr Thomsett.

Ensure that the vaccination record of any bought-in stock is up to date and quarantine these animals, to ensure they are fit and healthy before entering the herd.

Carrying out a herd health check to establish health status and therefore which vaccinations are needed is greatly beneficial, said Dr Thomsett.

Viruses can also be carried in semen so ensure this comes from a reliable source.

Age of animal has a role to play in herd fertility too – although older sows often produce bigger litters they mostly have a higher pre-weaning mortality.

And weaning weight is higher in young pigs – sows aged parity six and older can produce lighter pigs.

Farming Connect, which is delivered by Menter a Busnes and Lantra, has received funding through the Welsh Government Rural Communities – Rural Development Programme 2014-2020, which is funded by the European Agricultural Fund for Rural Development and the Welsh Government.