Abstract
This study aimed to ascertain if oral hydration is an effective adjuvant treatment for bovine respiratory disease. To achieve this objective, clinical and performance outcomes were compared between the calves affected by bovine respiratory disease (BRD) treated with an antibiotic (florfenicol) and a non-steroidal anti-inflammatory drug (NSAID - meloxicam) [group not hydrated (GNH)] and the calves receiving the same antibiotic and NSAID plus an adjuvant therapy based on oral hydration [group hydrated (GH)] at 7% of the body weight (BW) for 5 days. A group of healthy calves, from the same batch and age, was also included as negative control. Crossbred calves (Aberdeen Angus-Holstein Frisian) were enrolled based on a clinical BRD score (0-3 points per clinical sign: rectal temperature, nasal discharge, eye discharge, cough, and ear/head position) during the first 21 days of the fattening period. Thus, a calf was designated BRD-affected if it had a BRD score equal to or higher than 5 points. The BRD-affected calves (n = 130) were randomly allocated to the GH (n = 65) or GNH (n = 65) groups. Clinical score was monitored after 4 days to determine curation or retreatment. Performance outcomes [body weight (BW) and average daily gain (ADG)] were also measured in both experimental groups and in the negative control group at days of inclusion (42 and 80 days) since the beginning of the trial. Throughout the trial, GH showed a significantly (p ≤ 0.05) lower clinical score after 4 days and a complete absence of BRD cases becoming chronic compared to GNH. When BW data were analyzed using a multivariable model, considering BW at day 0 as a factor in the model to accurately estimate BW2, BW3, ADG2, ADG3, and ADG global, GH calves showed significantly (p ≤ 0.05) higher ADG throughout the trial (at 42 days, 42-80 days, and inclusion-80 days) compared to the GNH ones. In this study, fattening calves with clinical BRD, receiving antibiotic and NSAIDs plus an adjuvant therapy, based on oral hydration at 7% of their BW for 5 days, had better curation rate, less chronic cases, and better performance parameters compared to calves that only received antibiotic and NSAIDs.