Rotavirus disease can intensify within a herd when infected calves shed the pathogen into the environment, exposing and infecting other calves. A recent study by Dr. Andy Skidmore*, in collaboration with Dr. Jan Gawthrop, evaluated if First Defense Tri-Shield, a polyclonal antibody scours preventative, could reduce rotavirus shedding. Results showed First Defense Tri-Shield significantly reduced rotavirus shedding versus control calves, which all achieved successful passive transfer from a quality colostrum feeding.

The study enrolled 20 calves, separating them into two treatment groups. The first group of 10 calves received one 30-cc tube of First Defense Tri-Shield followed by four liters of pooled colostrum. Representing the control group, the next 10 calves received a placebo tube and four liters of pooled colostrum. The veterinary staff administering the tubes and recording data were blinded to the difference in treatments. On Day 6, all calves were challenged with live rotavirus. Health scores, including fecal scores, were recorded twice daily on days 8, 10, 14 and 18.

The results showed that all calves received successful passive transfer, yet compared with the control group, First Defense Tri-Shield provided a beneficial additive effect to quality colostrum by significantly reducing rotavirus shedding. Control calves had higher rotavirus shedding than the First Defense Tri-Shield calves on all sample days, with Day 8 (two days post challenge) being significantly higher. Researchers at the University of Wisconsin Diagnostic Lab used quantitative PCR to quantify the amount of rotavirus DNA particles present and threshold cycle frequency to compare rotavirus shedding between treatments. The higher the threshold cycle frequency the less rotavirus particles were being shed into the environment. (See Figure 1 – Threshold Cycle Frequency)

“While First Defense Tri-Shield is proven to reduce scours caused by K99+ E. coli and bovine coronavirus, plus reduce the severity and duration of scours caused by rotavirus, this study confirms that it also significantly reduces rotavirus shedding,” says Bobbi Brockmann, Vice President of Sales and Marketing with ImmuCell. “Producers now can limit the environmental pathogen load, reduce the level of disease challenges herd mates are exposed to and reduce the frequency and severity of scour outbreaks.”

*A. Skidmore, J. Gawthrop, D. Hurley, S. Sturgeon, & S. Hayes. First Defense Tri-Shield reduces rotavirus shedding in newborn calves: Protect the calf and the environment [White paper].