Awardee Talk: Effects of a Supplemental Water Source and Trace-Mineral Based Electrolyte Drinking Solution on Intake, Performance, and Health 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. The significant loss of water and key nutrients from the body can put the animal at increased risk for bovine respiratory disease (BRD). It is hypothesized that rapidly rehydrating calves upon arrival may reduce disease risks by facilitating an easier transition to the feedlot and limiting loss in value due to illness and decreased performance. The objective of this study was to rapidly replenish water and key nutrients in newly received feedlot calves by assessing water intake (WI) and providing a supplemental water source or a nutritional rehydration solution during the first three days after arrival. Crossbred heifers [n= 270; initial BW = 232 ± 16 kg] were individually weighed after 11 h transportation 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; and 3) Nutritional rehydration solution (NRS): trace-mineral based drinking solution provided with one stock tank/pen. 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 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, dry matter intake (DMI), average daily gain (ADG). 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). The ADG was less for NRS than CON from days 1 to 4 (P = 0.01); however, treatments did not affect ADG from days 5 to 56 (P ≥ 0.12). No treatment or treatment × day or experimental period effects (P ≥ 0.061) were observed for BW and gain:feed (G:F). Treatments did not affect morbidity and mortality (P ≥ 0.20). 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 and NRS when compared with CON (P ≤0.05). Bovine viral diarrhea virus (BVDV) antibodies increased for NRS when compared with SWS and CON (P = 0.004). The results suggest that providing SWS or NRS to newly received calves during the initial three days after arrival increases WI, DMI, antibodies against respiratory viruses, hydration, but has little impact on performance, blood metabolites, and immune cells.