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How to Limit the Impact of Heat Stress on Sows through Feeding Strategies

In the summer, and all year long in tropical areas, sharp rise in high temperatures can cause heat stress resulting in poor performance in pig farming. In sows, this condition is manifested by a decline in feed intake, a lower fertility and decreased lactation performance. Sows are all the more sensitive to heat stress as their requirements are extremely high after farrowing. How can one help sows overcome the harmful impact of heat stress? Below is a number of provisions that can be put in place to counteract these potential negative effects.

What are the effects of heat stress on sows?

Heat stress can have serious consequences on a sow because of this animal’s acute sensitivity to heat. When she is subject to high temperature variations, there comes a point when the sow is no longer able to regulate her interior body temperature.

This condition does not only stem from high temperatures, but from the combination of temperature and humidity, and their ensuing effects on the animal condition.

In sows, heat stress causes decreased feed intake and increased water intake.

The extent of consequences can be observed through different signs:

  • lower lactation feed intake resulting in lower milk production and lower weaning weights
  • increased body condition loss during lactation resulting in decreased post-wean fertility
  • Decreased farrowing rates due to lowered conception rate.

relative humidity sow stress heat

heat stress consequence sow feed intake piglet weight
 Effect of temperature on sow feed intake and piglet
weaning weight (Source: Quiniou and Noblet, 1999)

How to adapt sow’s feed in order to limit the impact of heat stress?

In pig farming, feeding strategies are an efficient method to limit the extent of heat stress on animals, particularly in sows. Therefore you can compensate for the decline in sows’ feed intake by reformulating their feed, as follows:

  • Increasing the energy concentration of feed to compensate for lower feed intake. In terms of energy sources, it is preferable to use raw materials that have a high fat content rather than raw materials that are high in starch.
  • Incorporating a smaller amount of fibers (as the fiber fermentation process produces heat).
  • Increasing vitamins, minerals and amino acids according to the energy level in the feed.
  • The negative effects of ROS stemming from heat stress can be counteracted by adding antioxidants: Vit E, Se, Vit C, natural polyphenols

Many other elements should also be considered in order to reduce the impact of heat stress on a sow's metabolism.  Make sure that the aforementioned measures are adjusted according to the size of the farm, the breeding season and the farm’s geographical location. Our experts are here to help you design feeding strategies that are tailored to each specific case. Please contact us if there is any way we can be of assistance!


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