Abstract
The objectives of this study were to evaluate the prophylactic use of SB-300 (Jaguar Animal Health, San Francisco, CA), a standardized botanical extract isolated from the bark latex of Croton lechleri, on reducing fecal water losses and diarrhea events in Holstein bull calves individually housed under a restricted whole-milk feeding regimen (6 L/d) from 1 to 25 d of life. Fluid therapy administration due to dehydration, average weight gain, and the fecal microbiome were also evaluated. Bull calves used in this study were born from normal parturition, fed 4 L of pooled pasteurized colostrum by esophageal feeder, and moved to a research facility at Cornell University (Ithaca, NY). A double-blinded randomized clinical trial was designed to allocate a total of 40 newborn calves into 1 of 2 treatment groups: calves receiving (twice daily) a solution containing 500 mg of SB-300 added to the whole milk for the first 15 d of life (SB-300, n = 20) or a control group receiving sterile water added to whole milk for the same period (CTR, n = 20). Treatment solutions had a total volume of 10 mL per treatment. Data regarding fecal dry matter were collected to precisely measure water content in fecal samples and to define diarrhea events; the SB-300 group had significantly increased fecal dry matter during the study period. Additionally, significantly fewer events of diarrhea were observed for calves in the SB-300 group (16.9%) compared with calves in the CTR group (46.5%). Dehydration status was evaluated and treated accordingly; calves with moderate dehydration were offered oral electrolytes, and calves with severe dehydration were rescued with intravenous fluid therapy. Calves in the SB-300 group had fewer intravenous fluid therapies administered during the study period (1.6%) compared with the CTR group (3.1%). Overall fluid therapy administered (oral electrolytes plus intravenous fluids) was significantly higher for the CTR group (9.2%) compared with the SB-300 group (6.1%) during the study period. No differences in milk consumption, calf starter intake, or weight gain were observed between treatment groups. A single time increase in Bifidobacterium was observed on d 20 of life for the SB-300 group; otherwise, no differences in fecal microbiome profile were detected between treatment groups. These results suggest that 500 mg of SB-300 added to the milk for 15 d can reduce the incidence of diarrhea and reduce severe dehydration in milk-fed calves.