Table IV.

Antimicrobial treatments stratified by whether animals converted to a resistant status to specific antimicrobials during the feeding period

Antimicrobial resistance to:	Treatment during feeding period	Resistance conversionb	No conversion	Total cattle
AMPa	No	22	31	53
	Yes	24	18	42
	Total	46	49	95
TCY	No	38	15	53
	Yes	34	8	42
	Total	72	23	95
SMX	No	6	47	53
	Yes	5	37	42
	Total	11	84	95
TMP/SSS	No	2	51	53
	Yes	0	42	42
	Total	2	93	95
TMP	No	3	50	53
	Yes	0	42	42
	Total	3	92	95

^aAMP — Ampicillin; SMX — Sulphamethoxazole; TCY — Tetracycline; TMP/SSS — Trimethoprim/sulfanilamide; TMP — Trimethoprim.

^bResistance conversion was defined as an animal having more resistant isolates present preslaughter than at arrival.