The effect of sodium and chloride on pigs is not a new topic, but their role in early weaned pig diets is. Don Mahan, Ohio State University swine nutritionist, is researching this area and hopes to see more done in the future.

“From the time a pig is born through the first five weeks of life, the stomach’s chloride secretion is very low,” says Mahan. Piglets need chloride for several bodily functions, but it’s most important to the stomach.

“It keeps pathogenic bacteria population growth down. But more importantly, it aids protein digestion,” says Mahan.

Piglets can handle the highly digestible protein in sow’s milk well enough. But when you wean them and try to feed starter diets, the baby pigs don’t have enough chloride to process the new and foreign proteins effectively.

“A young pig’s sodium requirement may be higher than expected, especially two weeks after weaning,” says Mahan.

Complicating the issue is the fact that proteins are a buffer ù they neutralize acid conditions. “Proteins bind the chloride and buffer the stomach, preventing the chloride from doing its job well,” Mahan points out.

What’s the fallout? Pigs don’t eat and don’t grow. They hit the infamous wall. 

Products like blood plasma and whey have allowed you to wean pigs earlier because they’re so highly digestible. On the plus side, they also have relatively high chloride content. But, due to their high protein levels, those products also have a high buffering capacity. “So we’ve found even with plasma proteins you have to add salt in order to enhance performance and protein digestibility,” notes Mahan. 

The catch is that because this is a newly explored area, there aren’t any concrete answers  What sodium and chloride levels should you provide to  weaned pigs is still to be determined.

For now, Mahan offers this advice: “The time between weaning and five weeks of age is not the time to save on chloride.”