Keeping sows productive during summer season

Ameer A. Pahm, D.V.M., PhD


 Summer months are often potentially problematic for our nursing sows.  During peak of summer, temperature can reach 35oC , which is a far too warm for sow comfort.  In general, sows feel more comfortable at temperature range of 15 to 20oC.  Temperatures above 27oC are thermally stressful.  Sows that nurse a litter 8 to 10 piglets need to consume about 6 or more kilos of feed a day.  Philippines generally have high relative humidity, which makes summer temperatures worse.  Pigs do not have sweat glands, which makes them more sensitive to heat stress when both temperature and humidity are high.  When they feel warm, sows will not eat as much, which will lower the amount of milk they produce, and eventually results to thinner piglets at weaning.  Sows that don’t eat enough will deplete their own body reserves, resulting to sows losing too much weight (>15 kg) at the end of the nursing period.  Sows that are too thin will have delayed return of heat (>9 days), and may have reduced number of productive years. 


Here are some tips to keep the sows healthy and productive during summer:


Water is important.  Make sure water is always available to the sow.  Not only is the availability of water important, but the temperature of the water (less than 15 degrees) and the pressure of the water from the drinkers (1 to 2 liters per minute) is also critical.

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The most important effect of high ambient temperature on sows is on reduction of feed intake.


 Keep the sows cool.  During the hottest part of the day, spray mist, and drip coolers may help the sow keep its body temperature at a comfortable level.   Putting shades that will block direct exposure the sunlight will help as well. Industrial cooling fans /ventilators may be placed inside the house to move the air, and reduce humidity.


Feed frequently to keep feed intake high.  It may be helpful to feed the sows more during the cooler part of the day, which is the early morning, and early evening. Sows generate heat when they eat.  They will eat more if they are able to keep their body within their comfort zone.  In general, sows are fed twice (morning and afternoon).  During summer, however, feeding smaller amounts per feeding time, and adding extra feeding time in the evening is a common practice in many farms. 

Choose feed that is low in fiber, high in fat.   Feeds that are high in fiber (>4% of feed) can make the sow feel fuller, which can lower their total daily intake. Choose lactation feed that is high in quality grain sources such as maize and wheat, and less of feed by-products.  The presence of added fats and oils will also make the feed more palatable, and will raise the amount of energy in the feed.