PSI-17 - Effects of a Supplemental Water Source and Trace-mineral Based Electrolyte Drinking Solution on Intake and Blood Cell Count of Newly Received Feedlot Calves

Abstract: Rapidly rehydrating newly received feedlot cattle may reduce disease risks caused by the marketing and transportation-related restrictions on feed and water. This study evaluated strategies to rapidly replenish water and key nutrients in newly received feedlot calves during the first three days following arrival. Crossbred heifers [n=270; initial BW = 232 ± 16 kg] were individually weighed after 16 h fasting and sorted into 18 pens (6 pens/treatment). Treatments were: 1) Control (CON): standard in-pen automatic water source (Richie CM480; one waterer/pen); 2) Supplemental water source (SWS): CON + one additional stock tank/pen; 3) 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 1 to 4, after which supplemental tanks were removed. From days 5 to 56, cattle only had access to CON (automatic waterer). Water intake (WI) was measured daily throughout the trial, BW and whole blood (5 heifers/pen) were collected on days 1, 4, 14, 28, and 56. Treatment × experimental period interactions (P≤0.03) were observed for WI and dry matter intake (DMI). The DMI was greater for both SWS and NRS than CON from days 5 to 15 (P≤0.01), and SWS had greater DMI than CON from days 16 to 29 (P=0.01). Both SWS and NRS had greater WI than CON from days 1 to 4 (P≤0.001), but not from days 5 to 56 (P≥0.36). No treatment effect or treatment × day interactions were observed for plasma glucose, non-esterified fatty acids, total red or white blood cell counts (P≥0.23). Hematocrit and hemoglobin decreased for SWS when compared with CON (P≤0.05). The results suggest that providing SWS or NRS to newly received calves during the initial three days after arrival increases WI, DMI and hydration, but does not impact blood metabolites and immune cells.