Heat stress in the summer months can impact productivity, especially for sows in lactation, explains Dr. Erin Holmes, swine nutritionist for Cargill. This is the time when maintaining high feed intake is challenging but feeding and management strategies can help alleviate the effects of heat stress, she says.

“Any nutrients we can get into her during lactation, especially when she’s challenged, will be of value to her – not just for lactation but also for subsequent litters,” says Holmes.

Nutrient concentration

“The common practice for a summer lactation diet change would be to increase lysine levels based on what we think the reduction in feed intake is going to be to achieve the same amount of amino acid intake,” Holmes says. “And then we would add fat to increase the energy density of the diet. Fat is a very concentrated source of energy. In addition, it facilitates fat-soluble vitamin absorption and provides some dust control.”

It also has a lower heat increment, which is important in the summer months.

“The amount of heat that is produced by the animal to digest and utilize a diet with fat is going to be lower than, say, other ingredients like fiber or protein,” she adds. “Bakery ingredients would be an alternative with higher energy, though not as high as fat because it’s a very energy-dense ingredient,” she says.

Distillers [grains] can come into lactation diets, too, but some producers are concerned about mycotoxins. There is additional heat with digestion but also diet savings.

Other management tips include:

• Set temperature curves correctly and make sure fans and cool cells function properly
• Monitor water intake, and make sure gilts are adjusting to a new water delivery system. “To know if a gilt or sow has consumed water after coming into farrowing, put a little peanut butter on the nipple waterer. It’s an attractant, but if the peanut butter is gone, there’s a high likelihood that she’s drinking water normally,” Holmes says.
• Group young females together in the farrowing barn to monitor more closely
• Feed sows in the cooler part of the day – adjust run-times of the lines accordingly
• Try dry-feeding to encourage feed intake
• Consider additives to stimulate feed intake (talk to your nutritionist)
• Get animals up at least once a day (but not in the hottest part of the day) to encourage eating and drinking

 “One of the biggest things to remember is the long-term downstream effect that summer lactation feeding intake has on the whole production system,” points out Holmes. “We’re talking about feeding sows in the summer but it’s the subsequent farrowing is really impacted.”

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