Effects of water source on health and performance of Mongolian free-grazing lambs

• Water pollution from animal waste is a current concern regarding Mongolian grazing lands.
• We provided lambs with water from a different source (upper stream, lower stream, well, and pond).
• Lambs that drank lower stream water showed increases in pathogenic E. coli infection, clinical diarrhea, and WBC count.
• Water intake was lowest in the lambs given well water, suggesting that they avoided drinking the water.
• Our study revealed the profound nature of the effects of water quality on livestock health and performance.

Water pollution from animal waste, and its influence on grazing animals, is a current concern regarding Mongolian grazing lands. We allocated 32 free-grazing lambs to four groups and provided each with water from a different source (upper stream, lower stream, well, and pond) for 49 days. We recorded the amount of water consumed by the lambs, as well as their body weight, white blood cell count, acute phase (haptoglobin) protein level, and fecal condition. We measured the chemical and biological qualities of the four types of water, and we detected enteropathogenic and enterohemorrhagic Escherichia coli in fecal samples by using a genetic approach. Pond water contained high levels of nitrogen and minerals, and well water contained high levels of bacteria. On day 15 of the experiment, the following parameters were the highest in lambs drinking water from the following sources: water intake (pond or lower stream), body weight gain (pond), WBC count (lower stream), haptoglobin concentration (well), and enteropathogenic E. coli infection rate (lower stream). Lambs given upper or lower stream water exhibited more severe diarrhea on day 15 of the experiment than before the experiment. Mongolian sheep seemed to adapt to chemically contaminated water: their productivity benefited the most from pond water, likely owing to its rich mineral content. Lambs that drank lower stream water showed increases in enteropathogenic E. coli infection, clinical diarrhea, and WBC count. Water intake was lowest in the lambs given well water, suggesting that they avoided drinking the water because of potential E. coli infection; they were thus at increased risk of negative health and production effects. Our study revealed the profound nature of the effects of water quality on livestock health and performance.