Submitted to: Arkansas Experiment Station Research Series
Publication Type: Other
Publication Acceptance Date: 6/25/2003
Publication Date: 12/1/2003
Citation: LOOPER, M.L., ROSENKRANS JR, C.F., AIKEN, G.E., EDRINGTON, T.S. ESCHERICHIA COLI AND SALMONELLA IN BEEF CATTLE GRAZING TALL FESCUE. ARKANSAS EXPERIMENT STATION RESEARCH SERIES. 2003. V. 509. P. 58-60. Interpretive Summary: Escherichia coli O157:H7 (EHEC) and Salmonella (SM) are two of the most common agents of foodborne illness in humans, and both bacteria have been isolated from beef cattle at all stages of production. Shedding of E. coli O157:H7 tended to be reduced in calves and was decreased in cows grazing endophyte-infected tall fescue. Knowledge of factors that may influence shedding of pathogenic bacteria, such as grazing endophyte-infected fescue, in cattle is necessary to decrease the incidence of bacteria-related illnesses in both cattle and the possible transmission of these bacteria to humans. This information is of interest to beef producers, extension personnel, and agricultural professionals who advise beef producers on beef management practices.
Technical Abstract: Fecal samples were obtained from Angus x Hereford cows (n = 49) and spring-born calves (n = 45) grazing endophyte-infected (E+) tall fescue or non-infected (E-) tall fescue during the summer to examine the effects on shedding of Escherichia coli O157:H7 (EHEC) and Salmonella (SM). One-half of the male calves were treated with a steroid implant at 60 d prior to fecal collection. Body temperature was measured from cattle at time of fecal collection. Overall, incidence of EHEC shedding averaged 8.4 and 7.6% for calves and cows, respectively. Salmonella shedding was 4.8 and 0% for calves and cows, respectively. Cows grazing E+ fescue were shedding fewer (P < 0.05) EHEC than cows grazing E- (1.8% vs 17% for E+ and E- cows, respectively). Likewise, EHEC shedding tended (P = 0.11) to be reduced in E+ calves (4.3%) compared with E- calves (13.9%). In calves, type of fescue grazed did not influence (P > 0.10) the incidence of SM shedding. Cow shedding of either EHEC or SM did not influence (P > 0.10) calf shedding of bacteria. Shedding of EHEC and SM in calves was not influenced (P > 0.10) by sex of calf or implant status. Shedding of E. coli O157:H7 tended to be reduced in calves and was decreased in cows grazing endophyte-infected tall fescue.