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United States Department of Agriculture

Agricultural Research Service

Title: Water Quality in Cattle Feedyard Playas in Winter and Summer

Authors
item Purdy, Charles
item Straus, David - TEXAS TECH UNIVERSITY
item Parker, David - WEST TEXAS A&M UNIVERSITY
item Williams, Brock - IBT REFERENCE LAB.
item Clark, Ray

Submitted to: American Journal of Veterinary Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 14, 2000
Publication Date: September 1, 2001
Citation: Purdy, C.W., Straus, D.C., Parker, D.B., Williams, B.P., Clark, R.N. 2001. Water quality in cattle feedyard playas in winter and summer. American Journal of Veterinary Research. 62(9):1402-1407.

Interpretive Summary: Regulatory authorities, which are under pressure from environmentalists and ultimately the public, are scrutinizing large feedyards in the Southern High Plains to make sure that air, water, and soil pollution do not adversely affect the public health. Although feedyards have stringent regulations on new permits, very little is known concerning the scientific microbial impact of feedyards on their environment. Animal waste, high in Gram negative bacteria, introduces high concentrations of endotoxin to the environment. Endotoxin, a heat stable substance and very biologically active in host animals, was a prime candidate to study in feedyard shallow lakes (playas). They analyzed seven feedyard and three non-feedyard playas for mean endotoxin concentrations and mean total fecal coliforms (TFC) in the summer and winter. Also, they studied 20 variables of water quality in two non-feedyard and four feedyard playas in the summer and winter. It was determined that feedyard playas were significantly higher in mean endotoxi concentration (8001 ng/ml and 9.21 X 10**5 TFC in winter and 8640 ng/ml and 4.6 X 10**7 TFC in summer) compared to 156 ng/ml and 2.7 X 10**1 TFC in winter and 267 ng/ml and 5.76 X 10**4 TFC in summer of non-feedyard playas. Eighteen of 20 water quality variables were higher in feedyard playas compared to control playas, and they increased the concentrations over years of time. It was concluded that the use of water from feedyard playas should be used with caution due to pathogens and high concentration of endotoxin. This water should not be aerosolized near humans or animals as it is an endangerment to their health. Over time, the increase of water quality variables indicated that little water was percolating downward.

Technical Abstract: The objective of this study was to determine the concentration of endotoxin, total fecal coliforms (TFC), and 20 water quality variables from feedyard shallow lakes (playas) compared to control playas in the winter and summer. This would determine, in part, the biological impact that feedyards have on the water environment. Duplicate water samples were collected at the air/water interface from seven feedyard playas, three control playas (north, south, west and east), and at various water depths from three playas. The Limulus lysate assay determined Endotoxin. Standard microbial methods were used to determine the total fecal coliforms, and standard methods were used to determine the water quality variables according to Environmental Protection Agency procedures. Mean endotoxin concentrations of feedyard playas were significantly higher (8001 ng/ml and 9.21 X 10**5 TFC in winter and 8640 ng/ml and 4.6 X 10**7 TFC in summer) compared to 156 ng/ml and 2.7 X 10**1 TFC in winter and 267 ng/ml and 5.76 X 10**4 TFC in summer of non-feedyard playas. Eighteen of 20 water quality variables were higher in feedyard playas compared to control playas, and the concentrations increased over years of time. It was concluded that the use of water from feedyard playas should be used with caution due to pathogens and high concentration of endotoxin. This water should not be aerosolized near humans or animals as it is an endangerment to their health. The increase of water quality variables over time indicates that little water was percolating downward.

Last Modified: 9/21/2014
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