PSIII-25 - The Effects of Varying Levels of Trace Mineral Supplementation on Mineral Balance and Antibody Concentrations in Feedlot Cattle

Trace mineral (TM) supplementation is critical for optimal performance and health. The objective was to determine the effects of varying levels of TM supplementation on feedlot cattle TM status and antibody concentrations. Angus steers (n = 240; BW = 291 kg ± 27.4) were stratified by arrival BW and source and assigned to 1 of 4 treatments (12 pens/treatment; 5 steers/pen). Treatments included a negative control (CON) in which cattle received no TM supplementation, a requirement treatment (1X) in which cattle received added TM at 2016 Nutrient Requirements of Beef Cattle required levels, a 2 times requirements (2X), and a 4 times requirements (4X) treatment. Selenium was included at 0.1, 0.2, and 0.3 mg/kg for 1X, 2X, and 4X respectively. Treatments were chosen based on reported TM supplementation levels from the 2015 Feedlot Consulting Nutritionist Survey. One steer was chosen at random from each pen to be evaluated for serum and liver TM status and antibody concentrations to respiratory viruses. There was treatment × day interaction for serum Co, and liver Cu and Se (P < 0.0001). Serum Co was greatest for the 4X treatment from d 28 through harvest. Liver Cu was greatest for the 2X and 4X treatments from d 56 through harvest. Liver Se was greatest for 2X and 4X from d 28 through harvest. There was an effect of day on liver Co, Fe, Mn, Mo, and Zn (P < 0.0001) and serum Cu, Mn, Mo, Se, and Zn (P < 0.0019). Concentrations for individual TM had different trends over time, however, all reported values were within normal ranges. Serum Zn was greater at harvest (P = .02). There was an effect of time on Bovine Viral Diarrhea Virus Type 1A, Bovine Herpesvirus Type 1, Bovine Parainfluenza 3 virus antibody titer concentrations (P < 0.0001).