Effect of administration of organic acids in drinking water on faecal shedding of E. coli, performance parameters and health in nursery pigs

This study evaluated the effect of altering the pH of drinking water on the excretion of Escherichia coli (haemolytic and total count) by nursery piglets under field conditions as well as their performance parameters and health. The pH of the normal drinking water (pH 8) was lowered by using a mixture of organic acids (lactic, formic, propionic and acetic acid) to obtain a final pH of 6, 5 or 4.Reducing the pH to 4 resulted in the excretion of less faecal E. coli compared to pigs given water of pH 8 (P < 0.05), but the fall in pH also significantly decreased water intake. The highest daily weight gain and lowest mortality rate were observed in the group receiving drinking water of pH 5 (P > 0.05). No significant differences in the clinical parameters measured were seen between groups. The results of this study suggest that lowering the pH of the drinking water in newly weaned pigs reduces the E. coli load.