Compatibility of sulfadimethoxine and ormetoprim with lasalocid and monensin on performance of male broiler chickens

We studied the effect of sulfadiomethoxine and ormetoprim (Rofenaid 40) in combination with lasalocid (Avatec) and monensin (Coban) on mortality, weight gain, and feed conversion of 2592 male broilers to 47 days of age. Four shuttle treatments were utilized: 1) monensin feeding for the entire trial; 2) sulfadimethoxine and ormetoprim feeding for the first 2 weeks, followed by lasalocid for the remainder of the trial; 3) sulfadimethoxine and ormetoprim feeding for the first 2 weeks, followed by monensin; and 4) sulfadimethoxine and ormetoprim feeding through week 3, then lasalocid for the remainder of the trial. No significant (P greater than .05) differences were observed in mortality among the four treatments. The combination of sulfadimethoxine and ormetoprim plus lasalocid significantly (P less than .01) improved weight gain and final body weight, but the length of time that sulfadimethoxine and ormetoprim were fed did not have any effect. Sulfadimethoxine and ormetoprim plus monensin treatment resulted in better feed conversion as compared with the other treatments.