MAGNESIUM-SULFATE EFFECTS ON COLIFORM BACTERIA REDUCTION IN THE INTESTINES, CECA, AND CARCASSES OF BROILER-CHICKENS

The objective of the study was to evaluate the effects of MgSO4 on intestinal and cecal content reduction with subsequent effects on carcass weight loss and coliform bacterial counts in the intestine and ceca, and on the processed carcass. Four hundred and eighty broiler chicks, 49 days of age, were fed MgSO4 at levels of 0, 2.5, 4.0, 5.5, 7.0, and 8.5 g/L via drinking water 24 h before processing. Samples from the intestinal and cecal contents and swabs from the processed carcass surface were plated for coliform bacteria colonization. The results indicated that carcass weight loss was not affected significantly by MgSO4, irrespective of the levels fed. The mean dressing percentage of the treated chicks was 64.9% compared with 65.2% for the controls. Although the reduction in the intestinal contents was not significant, the coliform bacterial counts declined from 1.4 x 10(6) to 1.4 x 10(4), a reduction of 2 logs when the MgSO4 was administered at 5.5 g/L. However, both the cecal contents and coliform bacteria were reduced significantly when the birds were given 5.5 g/L of MgSO4. The reduction of the coliform bacteria in the ceca was significant when compared with the control, an approximate reduction of 3 logs. Also, the bacterial counts on the carcass surface were nonsignificantly reduced from 2.2 x 10(4) to 2 x 10(3), a 1-log reduction. Correlation coefficients showed that as the contents of the intestine decreased, the coliform bacterial counts in the ceca and on the carcass surface decreased. Therefore, by lowering the contents in the intestine prior to slaughter, there is the possibility of reducing the level of bacterial contamination on the processed carcasses.