On-farm management decisions to improve beef quality of market dairy cows.
A 3-phase study was conducted to assess on-farm management decisions to reduce antibiotic residue violations and improve carcass characteristics in market (cull) dairy cows. In Phase 1, questionnaires were mailed to dairy producers (n = 142) to determine current on-farm management strategies for reducing antibiotic residues in market dairy cattle. In Phase 2, Holstein market cows (n = 77) were assigned randomly to each of the 3 feeding treatments (0, 30, or 60 d). Average daily gain (ADG), body condition score (BCS), and carcass characteristics were assessed. Phase 3 determined the meat withdrawal time of Holstein cows (n = 62) administered procaine penicillin G. Eighty-six percent of dairy farms responding to the questionnaire had at least one cow condemned annually, and no producer had a designated feeding protocol for market cows prior to selling. In Phase 2, ADG was greater in cows fed for 30 d (1.4+/-0.6 kg/d) than in cows fed for 60 d (0.9+/-0.4 kg/d). Additional feeding did not influence the carcass characteristics studied with the exception of kidney, pelvic and heart fat, which was higher in cows fed for 60 d compared with those fed for 0 and 30 d. In Phase 3, 31% of cows treated with procaine penicillin G exceeded the 10-d label withdrawal recommendation by an average of 3.1+/-1.9 d. Feeding market cows may not influence carcass characteristics, but can increase ADG and may ensure that recommended meat withdrawal times for antibiotics are exceeded.
Rogers
C A
CA
Department of Animal and Range Sciences, New Mexico State University, Las Cruces, NM 88003, USA.
Fitzgerald
A C
AC
Carr
M A
MA
Covey
B R
BR
Thomas
J D
JD
Looper
M L
ML
D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D001823:Body Composition; D002417:Cattle; D003612:Dairying / Q000379:methods*; D004032:Diet; D004350:Drug Residues / Q000032:analysis*; D005260:Female; D008460:Meat / Q000032:analysis*; D010402:Penicillin G Procaine / Q000008:administration & dosage; D011786:Quality Control; D011795:Surveys and Questionnaires; D015430:Weight Gain
D000900:Anti-Bacterial Agents; D010402:Penicillin G Procaine