Quality of drinking water in Italian turkey farms: chemical-physical and microbiological comparison of well and aqueduct supply

Purpose: Reg.852/2004/EC establishes requirements for livestock drinking water as “potable or clean” without specifying any qualitative limit. Groundwater is frequently used as a source of supply, but may be subjected to contaminant infiltration (inorganic substances and bacteria) and sometimes unsuitable as a mass medication vehicle (e.g. hardness higher than 200mg/L may interfere with tetracycline dissolution and adsorption). Limited data are available regarding the chemical-physical and microbiological quality of drinking water for turkeys in Italy. This study aimed at describing water quality in 14 turkey farms supplied with well water (WW) and 14 farms with aqueduct water (AW). Methods: Salinity, hardness, pH, ammonia, sulfate, phosphate, nitrate, chromium, copper and iron were quantified in each sample. Total bacterial count at 22°C and 37°C, presence and enumeration of Enterococcus spp. and E. coli, and presence of Campylobacter spp. were evaluated. Water samples were collected in winter and in summer at 3 sites: at the water source (S), in the tank where drugs are mixed for medicated water preparation (T) and at the nipple line (N). Results: Chemical-physical profile of WW and AW was mostly within the limit of tap water for human use (Counc.Dir.98/83/EC), despite hardness ranged between 80-500mg/L. Iron in WF had a maximum of 0.7mg/L at S and of 1.5mg/L at N. At S, microbiological quality of both WW and AW was mostly within the limit of tap water, while being poor at T and N (e.g. up to 4,400 CFU/100mL of E. coli in WW and 1,300 CFU/100mL in AW). C. jejuni and C. coli were isolated only once, in WW and AW respectively, both at T site. In winter the prevalence of real time PCR positivity exceeded 70% of both WF and AW farms; in summer it was 43% of WW farms and 71% of AW farms. Conclusions: These preliminary findings indicate some criticisms in hardness and cleaning/disinfection procedures of pipeline. Relevance: This is relevant for further studies aimed at determining the correct dosage of drugs delivered to livestock via medicated water, taking into account a decreased solubility/stability in water and the presence of pipeline microbiota. Project RC IZSVe 10/11.