As I listened to Tom and Sally Brown, organic dairy farmers from Groton, New York, describe their struggle with Johne’s, I was reminded of what Dr. Ann Wells, D.V.M., from Arkansas says about cattle stress and its relation to health. This makes so much common sense — not just for Johne’s, but for most diseases and production/reproduction problems: Stress is a major contributor to disease in animals.
When doing farm calls, Wells likes to first observe the cows from a distance in a pasture or in the barn, keeping close track of which animals are not with the rest of the group or who are acting “differently.”
As she walks toward the group, she notices which animals don’t readily get up or act in a predictable manner. She feels that those outliers can be to be early indications of sub-clinical problems, and can help alert a farmer to where management changes are needed.
She then analyzes the body condition of each animal, noticing body fat, hair quality and other factors, which can indicate low-grade conditions. Even noting which animals have the most flies around them is important — flies seem to bother weakened animals more than strong animals.
Sudden or acute stress is often much less of a problem to animals than chronic or periodic stress which can seriously depress the immune system. While it is often easy to detect the causes of acute stress — calving, disease, sudden changes in temperature, it is often more difficult to notice chronic stress because it comes on gradually.
Some common causes of chronic stress include nutritional inadequacy, lack of sufficient clean water, mycotoxins in feed, mud or ice, stray voltage, lack of ample bedding or other discomfort in stalls, and internal parasites.