Evaluation of total and fecal coliforms in drinking water for pigs using NMP at the UAC-CP farm

Abstract

This study evaluated the microbiological quality of water for pig consumption at the UAC-CP farm, due to the historical incidence of gastrointestinal problems and mortality in piglets. The presence of total coliforms (TC) and fecal coliforms (FC) was quantified using the Most Probable Number (MPN) technique at six points in the distribution network, from the source to the automatic drinkers in the maternity and weaning areas. The results revealed excessive and widespread microbial contamination at all points, far exceeding the maximum limit allowed by the Bolivian Standard NB 512 (< 2 MPN 100ml^-1). TC concentrations ranged from 169.0 MPN 100ml^-1 (Campus Leahy Tank) to 1 635.0 MPN 100ml^-1 (Maternity Tank). Meanwhile, FC concentrations varied between 27.0 MPN 100ml^-1 (Campus Leahy Tank) and 1 589.0 MPN 100ml-1 (Weaning Drinkers). These values exceed the regulatory limit by more than 800 times. Contamination increased progressively throughout the system, with maximum levels in the tanks and drinkers of the maternity and weaning areas, attributed to biofilm formation and organic matter accumulation. The high FC load indicates direct fecal contamination and a potential risk of pathogen presence. The findings explain the episodes of colibacillosis and underscore the urgent need to implement corrective measures, such as cleaning, disinfection, and chlorination of the water system.