Monitoring beef cattle productivity as a measure of environmental health

Domestic livestock have occasionally been used as sentinels of environmenta l health. Historically, these studies focused on measuring blood or tissue levels of a specific environmental contaminant. For many environmental expo sures, however, there is no appropriate biomarker for exposure. The objecti ve of this study was to examine productivity and health information from do mestic livestock as one indicator of the potential long-term environmental impact of natural gas developments in a rural area. Intensive biological ac counting methods were developed to measure the health and productivity of c ow-calf herds surrounding a new sour natural gas processing plant. From the fall of 1991 through calving 1997, cow production records from 7040 record ed bull contacts were examined from seven area cow-calf herds. Detailed inf ormation was also collected on other risk factors known to influence beef h erd productivity. The median risks for nonpregnancy, abortion, calving late , stillbirth, and calf mortality for local herds did not differ from those of other published reports. There was no significant change in the risk of nonpregnancy, abortion, calving late, stillbirth, or calf mortality. (C) 20 01 Academic Press