Efficacy of European starling control to reduce Salmonella enterica contamination in a concentrated animal feeding operation in the Texas panhandle

Abstract

Background: European starlings (Sturnus vulgaris) are an invasive bird species known to cause damage to plant and animal agriculture. New evidence suggests starlings may also contribute to the maintenance and spread of diseases within livestock facilities. Identifying and mitigating the risk pathways that contribute to disease in livestock is necessary to reduce production losses and contamination of human food products. To better understand the impact starlings have on disease transmission to cattle we assessed the efficacy of starling control as a tool to reduce Salmonella enterica within a concentrated animal feeding operation. We matched a large facility, slated for operational control using DRC-1339 (3-chloro-4-methylaniline hydrochloride, also 3-chloro p-toluidine hydrochloride, 3-chloro-4-methylaniline), with a comparable reference facility that was not controlling birds. In both facilities, we sampled cattle feed, cattle water and cattle feces for S. enterica before and after starling control operations.

Results: Within the starling-controlled CAFO, detections of S. enterica contamination disappeared from feed bunks and substantially declined within water troughs following starling control operations. Within the reference facility, detections of S. enterica contamination increased substantially within feed bunks and water troughs. Starling control was not observed to reduce prevalence of S. enterica in the cattle herd. Following starling control operations, herd prevalence of S. enterica increased on the reference facility but herd prevalence of S. enterica on the starling-controlled CAFO stayed at pretreatment levels.

Conclusions: Within the starling-controlled facility detections of S. enterica disappeared from feed bunks and substantially declined within water troughs following control operations. Since cattle feed and water are obvious routes for the ingestion of S. enterica, starling control shows promise as a tool to help livestock producers manage disease. Yet, we do not believe starling control should be used as a stand alone tool to reduce S. enterica infections. Rather starling control could be used as part of a comprehensive disease management plan for concentrated animal feeding operations.

Figure 1

Estimated number of European starling within pen lanes. The mean number and standard deviation of European starling estimates from the starling-controlled and reference CAFO's during pre and post DRC-1339 starling control periods. All estimates were taken from 2 CAFO's located in Moore County, Texas from 18 January through 18 February 2010.

Figure 2

Salmonella contamination within cattle water troughs. The percentage of cattle water troughs testing positive on the starling-controlled and reference CAFO's during pre and post DRC-1339 starling control periods. All samples were collected from 2 CAFO's located in Moore County, Texas from 18 January through 18 February 2010.

Figure 3

Salmonella contamination within cattle feed bunks. The percentage of cattle feed samples testing positive on the starling-controlled and reference CAFO's during pre and post DRC-1339 starling control periods. All samples were collected from 2 CAFO's located in Moore County, Texas from 18 January through 18 February 2010.

Figure 4

Salmonella contamination within cattle fecal samples. The percentage of cattle fecal samples testing positive on the starling-controlled and reference CAFO's during pre and post DRC-1339 starling control periods. All samples were collected from 2 CAFO's located in Moore County, Texas from 18 January through 18 February 2010.