Dietary electrolyte balances in weanling diets for piglets

Dietary electrolyte balance (dEB), under most circumstances, is defined as milliequivalents (mEq) of sodium, potassium and chloride ions. Generally, a positive dEB level can optimize pigs’ growth, but a negative dEB may reduce feed intake. The optimal dEB for pigs is not well stablished as in the literature a range of -35 to 250 mEq/kg has been reported with similar results. The objective of this experiment, therefore, was to investigate the effects of different levels of dEB. A total of 160 weanling pigs ((Duroc × Landrace) × Yorkshire; average initial body weight of 7.67 ± 0.97 kg, 28 ± 1 d of age) were allotted into 1 of 4 treatments to determine effects of dEB (Na + K − Cl mEq/kg of the diet) on growth performance and nutrient digestibility. Pigs were fed 4 diets with different dEB levels: 0, 83, 166, and 250 mEq/kg of dEB for 4 weeks. Various dEB values were obtained by altering the concentrations of calcium chloride, calcium carbonate, and sodium bicarbonate.

Pigs fed diets with dEB of 166 and 250 mEq/kg exhibited greater average daily gain (ADG) than those fed 0 mEq/kg diet throughout the experiment. During d 14–28 and d 0–28, the average daily feed intake (ADFI) was greater in 166 and 250 mEq/kg dietary treatments compared with 0 mEq/kg dietary treatment. However, no difference was observed on gain to feed ratio between dietary treatments throughout the experiment. The 166 and 250 mEq/kg dietary treatments had greater apparent total tract digestibility (ATTD) of dry matter and nitrogen compared with 0 mEq/kg dietary treatment. There was no effect on ATTD of gross energy between dietary treatments.

Taken together, these results suggested that dEB values ranging from 166 to 250 mEq/kg allowed pigs to obtain optimal growth and better ATTD of DM and N.