Dorton, Kristy L., authorEngle, Terry E., advisorJohnson, Celina R., committee memberHamar, Dwayne W., committee memberSiciliano, Paul, committee member2016-04-052016-04-052005http://hdl.handle.net/10217/171882Steers were utilized to determine the effects of trace mineral (TM) supplementation and source, growth implants, and morbidity on performance, TM status, immune function, carcass characteristics, and lipid metabolism. In experiment 1, steers were backgrounded at their respective ranches for 30 d post weaning on one of the following treatments: 1) control (no supplemental TM), 2) inorganic TM, and 3) iso-amounts of organic TM. After the 30 d backgrounding period, steers were transported to the feedlot where half of the steers per treatment were implanted and the remaining half were not implanted. In experiment 2, the first group of steers was inoculated intranasally with IBRV four months prior to weaning. The second group was inoculated with IBRV on arrival to the feedlot and the third group was not inoculated with IBRV. Once at the feedlot, calves were sorted to treatments, which consisted of 1) organic TM and 2) iso-amounts of inorganic TM. During the backgrounding phase of experiment 1, calves supplemented with organic TM had a greater ADG and a lower incidence of morbidity than calves supplemented with inorganic TM. Steers supplemented with organic TM had greater concentration of total IgM during the growing phase and greater concentrations of antibody titer specific to ovalbumin than steers supplemented with inorganic TM. Steers that were implanted had a greater ADFI, REA, HCW, dressing percentage, and acetyl CoA carboxylase activity, and a lower KPH than non-implanted steers. In experiment 2, liver Mn and Zn concentrations were decreased in IBRV steers, whereas, Cu concentrations were unaffected. Inoculated steers had lower oleic acid (18:1 n-9) and monounsaturated fatty acids. Steers that were inoculated with IBRV prior to arrival at the feedlot had lower concentrations of myristic acid (14:0) and linoleic acid (18:2 n-6). Key Words: Steers, trace minerals, growth implants, induced morbidity, performance, immunity, carcass characteristics, lipid metabolism.doctoral dissertationsengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Trace elements in animal nutritionBeef cattle -- Carcasses -- QualityText