Editor’s note: The following information was presented by Matt Waldron, assistant professor of dairy nutrition and health with the University of Missouri, at the Penn State Dairy Cattle Nutrition Conference.

Imagine that one of your clients is having issues with its fresh pen. Eight of the last 40 cows that have freshened have not cleaned. Upon further investigation, you find that an additional 15 percent of the animals that did clean are showing signs of metritis within five to 10 days of calving.

Where do you look first?

Typical suspects may include calcium, protein fractions, energy, sulfur, selenium or Vitamin E. You probably will look to tweak one of these variables.

But, retained placentas can be really tough. It’s hard to know what causes them and exactly how to fix them, says Matt Waldron, assistant professor of dairy nutrition and health at the University of Missouri.

Waldron highlighted initial research from the 1980s and more recent research out of the National Animal Disease Center that was reported in 2002. Although this was ground-breaking research in the dairy industry, the results have largely not gained traction among dairy nutritionists and even many veterinarians. The research suggests that the immune system should not be overlooked when investigating the cause of any fresh-cow illness on the farm.

Although nutritional insufficiencies or excesses may specifically affect uterine metabolism and be the cause of retained placenta, don’t overlook the possibility of defective immune function.

Knowing how to fix the immune system is tricky.

In the case of retained placentas, immunocompetence plays a significant role in normal placental expulsion. “The placenta detaches from the uterus when immune cells come to the sites of placental attachment and basically chew through the connections,” says Waldron. If the immune system is not working properly, the immune cells will not release the placenta.

Therefore, any factor that impacts periparturient immunosuppression will impact the incidence of retained placentas; it’s not necessarily just one single nutrient.

The question we need to answer when solving fresh cow illness is how to do a better job of feeding animals around calving time for improved immune function, says Waldron.

There is not enough research available to say feed “x” grams of this nutrient to solve the problem. Rather, the solution lies in the small details, notes Waldron.

To minimize immunosuppression in your client’s herds, Waldron advises:

  • Ensuring that all vitamins and minerals are provided in the diet at NRC levels or higher and that nutrients are provided in highly bioavailable forms. “You want to make sure the nutrients in your ration are not just there on paper and that the cow is actually receiving them,” explains Waldron.
  • Minimizing negative metabolic impacts. Any sort of imbalance that causes metabolic problems impacts the immune system, and could cause retained placentas.
  • Minimizing stressors.
  • Preventing rather than simply managing problems.

Waldron reminds you not to overlook the immune system when investigating issues on your clients’ farms. On one farm, one thing may be the answer to improving immune function. On another, it could be a whole host of things. Bottom line: If you can maximize immunity around calving, you can really minimize health problems