WATER-QUALITY .2. THE EFFECT OF WATER NITRATE AND BACTERIA ON BROILERGROWTH-PERFORMANCE

Broiler chickens exposed to water sources contaminated with nitrate-ni trogen (1.90, 2.72, 3.55, or 5.19 mg/L) and added coliform bacteria (5 00 CFU/mL Escherichia coli or 100 CFU/mL Enterobacter cloacae) exhibit ed reduced (P < .05) body weights at 4 and 6 wk of age. Enterobacter c loacae was the most resilient under commercial-type housing conditions , as reflected by higher bacterial counts at the nipple drinker. Water treatment did not affect feed or water consumption. Both thymus and b ursa weight increased (P < .05) as level of nitrate and exposure to ba cteria increased. Liver and spleen weights were not affected (P > .05) by water treatment. This study further confirms the nonpathogenic but adverse effects of low-level water nitrate and bacterial contaminatio n on broiler performance.