PSXIII-19 Effect of a soluble trace-mineral based supplement on water intake, growth performance, and mineral status of newly weaned beef calves.

Abstract Early oral hydration and the provision of key nutrients may reduce the negative impact of stress related to post-weaning management, marketing, and transportation in newly received calves. This study evaluated a strategy to supply water and trace-minerals to newly weaned feedlot calves during the first 55 days following their arrival. Angus heifer calves (n = 18; initial body weight = 148 ± 11 kg) were individually weighed after 12 hours of fasting, housed in 6 pens (3 animals/pen), and randomly assigned to treatments (3 pens/treatment): Control (CON): no mineral supplementation, or Soluble Trace-Mineral Based Supplement (SUP): trace-mineral based drinking solution providing 3.0 g/head/d of mineral complex (Hidromix, Nutralmix, Argentina). The mineral solution was dosed in drinking water using a water-powered dosing pump (D9AL2, Dosatron, France). Heifers had ad libitum access to alfalfa hay (60.1% TDN, 14.2% CP on a dry matter basis). Water intake was measured daily throughout the experiment. Body weights (BW) were measured on days 0 and 55, and blood samples were collected on days 25 and 55 to determine Cu, Se, and Zn serum concentrations. Pens were considered the experimental unit, and data were analyzed using the PROC MIXED procedure of SAS, considering treatment and day as fixed effects and pen as a random effect. Water intake was greater for SUP than CON heifers (SUP = 17.6, CON = 15.6 L/d; P = 0.001) with no treatment × day interaction (P = 0.98). Treatments did not affect final BW (SUP = 173, CON = 170 kg; P = 0.90) or average daily gain (SUP = 0.420, CON = 0.444 kg; P = 0.91). There was no treatment effect or treatment × day interaction for Cu serum concentration (SUP = 72.3, CON = 73.1 µg/dL; P > 0.10). Serum Se concentration was greater in SUP than CON (SUP = 78.8, CON = 5.1 µ/l; P < 0.001) and a treatment × day interaction was observed (P = 0.05). The concentration of Zn tended to be greater in SUP than CON (SUP = 0.83, CON = 0.65 µ/ml; P = 0.07) with no treatment × day interaction (P = 0.98). The preliminary results suggest that providing a soluble trace-mineral supplement in drinking water enhances water intake and mineral status but does not result in increased growth performance in newly weaned beef calves.