Applied Research Note: Microbial composition of the biofilm of poultry drinking water system

Ensuring good water quality is one of the key management strategies to promote optimal broiler health and performance. A few studies have assessed the microbial status of drinking water for poultry, but there is insufficient information on biofilm in the drinking water lines within the poultry housing facilities. The buildup of microbes in the drinking water system could potentially result in biofilm formation which eventually deteriorates water quality. Hence, in this preliminary study, we sought to evaluate biofilm formation in the drinking water lines of selected broiler houses and characterize their microbial composition. Three random houses in each of 5 farms were visited representing 15 total houses used in this study. Using a borescope, we confirmed the presence of biofilm in 4 water lines per house on each farm, and a sterile gauze swab was used to collect the biofilm from these water lines. All biofilm samples were analyzed for the total aerobic plate count (APC), presence of yeasts and molds (YM), and Enterobacteriaceae (EB). The data were analyzed with ANOVA, and means were separated with Tukey's HSD test at P ≤ 0.05 using JMP software. All 15 houses evaluated had aerobic bacteria population and YM, whereas 7 out of the 15 houses had EB counts. For APC, there were significant differences across the farms (P < 0.0001) with Farm 1 having the highest APC (3.65 Log₁₀ CFU/mL) and Farm 5 having the lowest APC (2.05 Log₁₀ CFU/mL). For YM, significant differences existed across farms (P < 0.0001), Farm 2 had the highest counts (4.44 Log₁₀ CFU/mL), whereas Farm 5 had the lowest count (1.19 Log₁₀ CFU/mL). EB was detected in 3 out of the 5 farms and the counts were not statistically different (P = 0.07). Based on a sample size of 15 commercial broiler houses, these results suggest the need to evaluate water lines for biofilm and develop effective mitigations.