TY - JOUR AU - Rutten-Ramos, Stephanie C. AU - Simjee, Shabbir AU - Bargen, Jason L. AU - Vogel, Gary J. PY - 2021/12/31 Y2 - 2024/03/29 TI - Retrospective evaluation of excess death loss in feedlot cattle associated with in-feed tylosin application programs JF - The Bovine Practitioner JA - Bov. pract. VL - 55 IS - 2 SE - Articles DO - 10.21423/bovine-vol55no2p134-139 UR - https://bovine-ojs-tamu.tdl.org/bovine/article/view/8232 SP - 134-139 AB - <p>Daily feedlot records from steer and heifer lots slaughtered between January 2015 and December 2020 were evaluated for timing of tylosin programs and death events. Tylosin applications were described as<em> Any/None</em> (1/0) in the first 30 days-on-feed, <em>Any</em> in the middle feeding period, and<em> Any/None</em> (1/0) in the last 30 days-on-feed. The final analysis included 125,520 lots of cattle with 18,814,224 head placed. By year, week of the year, week on feed, sex type, hundred-weight at placement and tylosin program, weekly deaths were summarized as deaths per thousand head fed (Deaths_K). Using continuously fed tylosin lots as baseline for each summarized category, excess Deaths_K were calculated for each program. For each hundredweight group, mixed analysis of variance models were developed to assess differences in excess Deaths_K across tylosin programs. Overall, cattle not fed tylosin in the first 30 d in the feedlot experienced higher Deaths_K than cattle that were. Differences in excess death loss across tylosin programs were greater among cattle placed under 800 lb (363 kg) compared to heavier cattle.</p> ER -