Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/8/2004
Publication Date: 5/1/2004
Citation: Rogersei, C.A., Fitzgerald, A.C., Carr, M.A., Covey, B.R., Thomas, J.D., Looper, M.L. 2004. On-farm management decisions to improve beef quality of market dairy cows. Journal of Dairy Science. 87:1558-1564.
Interpretive Summary: Food safety is an important issue for the beef industry, especially with respect to meat from dairy cull cows which represents approximately 33% of beef production in the U.S. A three-phase study was conducted to assess on-farm management decisions to reduce antibiotic residue violations and improve carcass characteristics in market (cull) dairy cows. Feeding market cows can increase body condition score and daily weight gain, but may not influence carcass characteristics. Furthermore, feeding antibiotic-treated market cows may ensure recommended meat withdrawal times are exceeded. This information is of interest to extension personnel and agricultural professionals who advise dairy producers on management decisions.
Technical Abstract: A three-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 I, questionnaires were mailed to dairy producers (n = 142) to determine current strategies for eliminating market dairy cattle. In phase II, Holstein market cows (n = 77) were randomly assigned to one of three feeding treatments (0, 30, or 60 d). Average daily gain (ADG), body condition score (BCS), and carcass characteristics were assessed. Phase III determined the meat withdrawal time of Holstein cows (n = 62) administered procaine penicillin G. In Phase I, questionnaires indicated 5% of cows were condemned annually, predominately for malignant lymphoma or ocular neoplasia (cancer eye). Fifty-seven percent of respondents utilized computerized medication records. In Phase II, BCS increased in cows fed for 60 d (final BCS = 3.2 +/- 0.7) compared to cows fed 30 d (final BCS = 2.8 +/- 0.5). However, ADG was greater in cows fed for 30 d than for 60 d (1.4 +/- 0.6 vs 0.9 +/- 0.4 kg/d, respectively). Additional feeding did not influence carcass characteristics studied with the exception of kidney, pelvic and heart fat (KPH), which was increased in cows fed for 60 d, compared with those fed 0 and 30 d. In Phase III, clearance of procaine penicillin G, as determined by ELISA, ranged from 11 to 18 d post administration with 31% of cows averaging 3.1 +/- 1.9 d past the recommended 10 d label withdrawal. Feeding market cows can increase BCS and ADG, but may not influence carcass characteristics. Furthermore, feeding antibiotic-treated market cows may ensure recommended meat withdrawal times are exceeded.