Effect of Zelnate administered at initial processing in high-risk, newly received beef calves on performance and morbidity[1]

The objective of this study was to investigate the effects of Zelnate, a DNA immunostimulant, administered to calves (n = 261; BW 253 ± 4.0 kg) upon arrival, on morbidity and mortality, growth performance, and producer costs. Crossbred male beef calves (steers and bulls) were acquired from multiple auction markets and transported to the University of Arkansas stocker unit for a 42-d backgrounding period. Calves were randomly allocated to chute side into treatment groups: 1) Control (CON) in which no immunostimulant was administered or 2) Zelnate (ZEL), DNA immunostimulant administered. Animals were checked daily for signs of morbidity and treated with preplanned antibiotics. Records for morbidity and mortality were kept in addition to body temperature, clinical score, and body weight at the time of treatment. Data were analyzed using the GLIMMIX procedures of SAS. Significance was declared at P < 0.05 and tendencies were observed between 0.05 ≤ P < 0.10. No animals died during the duration of this study, however, Zelnate treated calves tended (P = 0.09) to have a lower relapse rate compared to control calves. Average daily gain was similar (P = 0.60) between the two treatment groups. This study also indicated that the treatment cost (Zelnate plus antibiotics) for the Zelnate group was more expensive than the cost to treat the control group (P < 0.01). Overall, our findings indicate that Zelnate administered upon arrival to high risk calves did not improve morbidity rates and respiratory treatment or affect performance, however it did increase costs by $9.24 per calf. Based upon these results, Zelnate does not appear to be an effective therapy for BRD when given upon arrival.