Excess insulin production – this is a product of feed (grain) intake exceeding 15% of the daily dry matter for significant periods, probably more than four to six weeks. Excess insulin speeds maturity. It also speeds old age.

High blood glucose – One of the costs of high insulin production and increase in aging, high blood glucose results from high-sugar grasses (mostly C3s) and grain. Ruminants and their digestive microbes operate better on starch derived from C4 grasses and plants.

Excess of free radicals – Free radicals tend to knock out the factories of the cell, which are the mitochondria. They result in a reaction similar to the glazing of a steak on a hot iron skillet. Free radicals are a normal part of physiology but are increased with high grain intake and decreased plant diversity. Plant diversity and maturity yields an increase in antioxidants and free-radical scavengers. Add to that improvements in soil mineralization, organic matter and microbes, and you will see slower aging of the cow herd.

Excess cortisol production – When cortisol was discovered in the late 1940s and early 1950s it was initially thought to be a wonder drug. That didn’t last long. We now know chronic stress = excess cortisol production = premature aging. High cortisol levels take out sensitive neurons in the brain and damage the central nervous system. Increased cortisol levels depress immune function. Stress yields cortisol release that is or can be excessive. A little is good. More is bad. The pacific salmon die soon after their highly athletic and stressful migration up the western rivers to spawn. The level of cortisol in these dying salmon is excessive and they age in a matter of days. Hard-fed cattle (and people for that matter) do the same thing at a slower rate.

Huge weight swings – Now that America’s No. 1 disease is obesity, followed closely with diseases such as Type II diabetes, it has become evident that calorie restriction and food with a low glycemic index are important to health and long life. Cattle need to gain and lose weight on an annual basis. But the swings need to be limited. A 1,000-pound cow in early December can be doing good in early March at maybe 850 pounds if she lost a pound of fat daily for 120 pounds. It is a totally different story if she dropped 50 pounds in five days and quickly lost a bunch of muscle mass as well.