The umbilical cord or “navel” connects the placenta and the fetus during pregnancy to allow for the movement of oxygen, water, essential nutrients, and removal of waste products between the cow and unborn calf. This cord contains 2 umbilical arteries, an umbilical vein, and a urachus. During parturition or calving, the umbilical cord separates from the fetus due to contraction of the smooth muscle around the umbilicus, which then exposes the umbilical structures to the external environment after calving. This exposure can allow environmental pathogens like Streptococcus species and E coli to enter the umbilical cord, causing infection. Think of the umbilical cord or navel string as a highway into the calf’s blood stream and is an open connection with the outside world after the calf is born. Infection of any or all of the umbilical structures can produce signs of inflammation, localized heat, purulent or malodorous discharge, and pain. This infection can also lead to bacteremia or infection of the bloodstream which can lead to infection in the joints (joint ill) and lameness, or even within the liver and lead to septicemia and death. According to the USDA, infection of the umbilical cord is the third most common illness in dairy calves following scours and pneumonia.
Prevalence of umbilical infection ranges in the literature from 1%-34%. It has been associated with decreased average daily gain, increased umbilical hernias, joint infections, and increased mortality. Some studies have shown that 29% of illness in calves could be attributed to navel associated issues. Although most calves survive these navel infections, their average daily gain is reduced in their first 3 months, and in worst cases, can result in a mortality rate of approximately 2%. Additionally, navel infection has been observed to cause 23% of preslaughter mortality and 54% of post slaughter condemnation in veal calves.
Prevention includes a wide variety of recommended management practices including excellent calving pen cleanliness and hygiene, colostrum management, and the use of antiseptic or antibiotic spray or dip.
Back in the fall, Dr Shannon wrote a short section in the Moos News regarding iodine teat dipping for navels. A recent study from University of Guelph in southern Ontario dairies looked at the effectiveness of a single application of 7% iodine tincture umbilical dip as a prevention of infection of the external umbilical structures in dairy calves. The study compared the single application of the iodine dip to no treatment, and found essentially no effect of iodine treatment on the incidence of external umbilical infection compared to controls. There were also no statistically significant differences between the iodine treatment group and controls in presence of umbilical hernias joint inflammation, scours, average daily gain, and mortality. So, it seems despite a wide acceptance among dairy producers worldwide about the beneficial use of iodine teat dips, its effectiveness may not be as proven. The one thing the study did show, was that the risk of umbilical infection was significantly reduced in calves that received colostrum sooner after birth. For every additional hour that calves received colostrum after birth, the odds of developing an external umbilical infection increased during the first month of life (Odds ratio 1.15). The study did suggest that future research should compare the use of other teat tips, and ideally compared with no treatment to determine effectiveness.
Another recent small field study in France compared the use of the Repiderma aerosol product in navel infection prevention. The study did not have a no treatment control group, but it did compare the use of a single treatment of Repiderma to a single application of 4% iodine in a group of 200 calves. It evaluated wet navels, navel discharge, pain reaction and total amount of calves having one or more navel issues at week one and two after application of either 4% iodine or Repiderma at birth. In the iodine group of calves, measurements of all the parameters were worse after the second week with more non dry navels, more navel discharge and pain reaction, as well as navel issues. In the Repidermagroup, measurements for all parameters improved in the second week, with none of the calves having navel related issues in the second week. The study does note it was a small observational study and so the differences were not statistically significant. As a bigger calf population would be needed, but it does claim an interesting trend towards improved naval health over iodine treated calves. Again, a negative control would be nice to show a difference over non treated calves as was described above with the iodine study, but it perhaps shows a possible alternative to iodine as a navel infection preventative. Added benefits may include cost as less product (approx. 10 ml) is used and every treatment is easy and hygienic compared to possible contamination of iodine teat dipping cups which are routinely used and may not be sanitized as often as they should in some dairies.