PSI-11 - Effects of a supplemental water source and trace-mineral based electrolyte drinking solution on intake and blood cell count of newly received feedlot calves

Oral hydration therapy has been used to improve performance and health of newly received feedlot calves; however, little is known regarding water intake (WI) following arrival at the feedlot. Our objective was to evaluate WI of newly received feedlot calves provided a supplemental water source or a novel nutritional rehydration solution during initial 3 days following arrival. Crossbred heifers (n=180; initial BW = 237 ± 23 kg) were individually weighed after 16 h fasting and sorted into 12 pens (4 pens/treatment). Treatments were: 1) Control (CON): water provided through standard in-pen automatic waterer only (Richie CM480; one waterer/pen); 2) Supplemental water (SUPW): CON + water provided with one additional stock tank/pen; 3) Novel nutritional rehydration solution (NRS): trace-mineral based drinking solution provided with one stock tank/pen as the only water source. Treatments were provided from days 0 to 3 after which supplemental tanks were removed. From days 4 to 14 all heifers had access to the standard in-pen automatic waterer only. The WI was measured daily throughout the trial and BW was recorded at days 0 and 14. Whole blood was collected (5 heifers/pen) on days 0, 3, and 14. Treatments had no effect on DMI or ADG (P ≥ 0.15). SUPW and NRS had greater WI than CON from days 0 to d 3 (P ≤ 0.001), but not from days 4 to 14 nor from days 0 to 14 (P = 0.69). No treatment effect or treatment × day interactions were observed for total red (RBC) or white blood cell counts (WBC; P ≥ 0.19); however, a day effect was present (P < 0.001) and RBC and WBC linearly decreased from day 0 to 14 (P < 0.05). Our preliminary results indicate that providing a supplemental source of water during the initial 3 d after arrival increased total WI and may facilitate rehydration in stressed calves following transit.