| dc.description.abstract | Complexed trace minerals (CTM) improve health and performance in multiple species, but species challenges differ. Objectives herein address species-specific challenges to 1.) Evaluate effects of supplemental Zn amino acid complex (ZnAA) during finishing phase on live performance, carcass characteristics and liver abscesses, with or without ractopamine hydrochloride (RAC) in beef steers and 2.) Understand CTM (Zn, Cu, Mn, Co) role in joint homeostasis in horses. The first objective was facilitated through pooling related finishing data from 9 studies (285 pens) across US and Canada between 2001-2016 using three statistical analyses. The initial analysis evaluated 3,840 crossbred steers. Results suggest ZnAA in the finishing period augments RAC and improves performance without negatively affecting carcass quality.
The second analysis separated effects of ZnAA and RAC using all data compiled. ZnAAxRAC describes reduced liver abscess (LA) occurrence/severity, but no ZnAA×RAC interactions for live animal performance, carcass characteristics, or carcass-adjusted performance were observed. Independently and together ZnAA and RAC improved growth performance and carcass characteristics without affecting dry matter intake, marbling, or back fat thickness. The third analysis divided pens into ZnAA levels: 0 ppm (NO), 30-54 ppm (LOW), and ≥60 ppm (HIGH). These data demonstrate positive linear response for growth and carcass characteristics. A quadratic tendency for carcass G:F suggests LOW is most efficient, and reduces LA occurrence/severity. The second objective used sixteen weanling Quarter Horses for 56-d measuring effects of CTM vs. inorganic minerals (Zn, Cu, Mn, Co) on intra-articular inflammation and cartilage metabolism following an acute inflammatory insult. Horses receiving CTM had a more robust immune response and increased collagen degradation, but increased aggrecan synthesis. Acute joint inflammation altered synovial fluid TM, and dietary source affected the degree of inflammatory response. Together these data suggest utilization of organic CTM has positive effects in beef cattle and horses. | en |
