2016-17 Rapid Ag: Evaluation of a Longer Duration Protocol to Heat-Treat Bovine Colostrum on Colostrum Characteristics, and on Passive Transfer, Health and Johne’s Disease Control in Minnesota Dairy Calves
Department of Veterinary Population Medicine
- 2016 Fiscal Year: $16,962
- 2017 Fiscal Year: TBD - Contingent on first year findings
Johne’s disease is a chronic intestinal infection of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). At an estimated $100 US loss per cow in Johne’s positive herds, Johne’s is one of the most economically important infectious diseases of U.S. dairy cattle, with losses attributed to progressive weight loss, reduced milk production and premature culling. It is estimated that MAP is present in 91.1% of U.S. dairy herds. There is a critical need for the Minnesota dairy industry to adopt control measures to reduce the prevalence and negative impact of Johne’s in commercial dairy herds.
Colostrum is an important source of protective immunoglobulins (IgG) but can be a source of exposure to important pathogens including MAP (Streeter et al., 1995). As such, Johne’s disease control programs must include preventing transmission of MAP through infective colostrum from infected cows. Several years ago this research team developed and validated a shorter duration colostrum heat-treatment (HT) protocol (60 ºC x 60 min) which eliminated most common pathogens and preserved colostral IgG (McMartin et al., 2006; Godden et al., 2006). Field studies have since shown improved passive transfer and reduced morbidity in preweaned calves fed colostrum HT using this 60 min protocol (Johnson et al., 2007; Donahue et al., 2012). However, a long-term controlled field trial conducted on 6 Midwest dairy farms recently reported no reduction in risk for MAP infection in cows that were fed colostrum HT at 60 °C for 60 min, as compared to cows originally fed fresh colostrum (Godden et al., 2015 submitted to JDSci). Furthermore, some colostral leukocytes, which can harbor MAP, have been shown to remain viable after the shorter duration protocol. As such, the 60 min protocol may not adequately inactivate MAP. This hypothesis is supported by two lab inoculation studies reporting that 90 min of treatment at 60 ºC may be required to eliminate MAP in colostrum (Godden et al., 2006; Personal communication. Dr. Noori. Razi Institute of Tehran. 12/3/2014).
Because early lab experiments at the U of MN demonstrated that bovine colostrum can be held at 60 ºC for as long as 120 minutes without causing a damage to IgG (McMartin et al., 2006), it may be possible that a longer duration protocol (e.g. 90 min) could be adopted to reduce the risk for MAP transmission through colostrum. However, the safety and efficacy of using this longer duration approach to HT colostrum requires formal evaluation on commercial farms where conditions (e.g. equipment, batch sizes) may differ from laboratory experiments. We propose to complete a 2-year (2-stage) study investigating the efficacy of a longer-duration (60 ºC x 90 minute) HT protocol. In the first year a pilot study will be conducted on a single farm to verify that the 60 ºC x 90 minute HT protocol does no harm to colostrum characteristics or passive transfer of IgG in neonatal calves. Assuming positive results in year 1, then in year 2 we would initiate a large-scale multi-herd field study to investigate if feeding colostrum HT at 60 °C x 90 min improves calf health as well as reduces risk of MAP transmission. If successful, the short-term benefits for Minnesota dairy herds adopting this longer duration HT protocol will include improved passive transfer of IgG and reduced morbidity in neonatal calves. Longer-term benefits will include reduced risk for MAP infection resulting in overall improved animal health and welfare as well as improved economic sustainability of MN dairy farms.
Complete a pilot study on a single farm to describe the effect of using a longer duration protocol to heat-treat colostrum (TX: 60 °C x 90 min) on colostrum characteristics (bacteria counts, IgG, leukocyte viability) and on passive transfer of IgG in calves, as compared to a positive control group (PC: colostrum HT at 60 °C x 60 min) and a negative control group (FR: Fresh colostrum).
(Contingent upon getting positive results in Objective 1.) Conduct a large scale, multi-herd, randomized controlled field trial to describe the effect of using a longer duration protocol to heat-treat colostrum (TX: 60 °C x 90 minutes) on passive transfer of IgG, preweaning morbidity and mortality, and on transmission of MAP in dairy calves, as compared to feeding fresh (FR) colostrum.