Several earlier posts discussed epigenetics and the consequences for the offspring of mothers: it's not just that what you eat you are, it is also that what your mother and grandmother ate affect what you are. This is sometimes called fetal programming.

There has been some interesting long term research going on for cattle that seeks to clarify the economic implications of this idea. The issue being investigated is the utility of protein supplements for range cows. They typically struggle through the winter on poor feed: dormant grasses that have shut down for the winter. There's enough energy in such "standing hay" to keep the cows gestating, but they are deficient in protein.

It apparently made no difference if such dry cows were given protein supplements. They didn't have better body condition, they didn't give more milk once they calved, and they didn't breed back sooner. It seemed to be a waste of money to supplement them. By the end of spring they were in no better shape than control herds that had not been supplemented in the winter.

However, their calves did better. The heifers grew better and were more fertile than the heifers from the controls. The steers gained better. The researchers hypothesize that they had been programmed in the womb for a world that had more and better feed, and if such feed was available they made good use of it.

There are still a lot of questions but something is going on. Was it that the calves of the malnourished groups had been programmed for a world of poor feed and so never achieved their genetic potential? What are the consequences for calves programmed for a good world if that good world doesn't materialze? Would they suffer more in hard times than calves that had been programmed for scarcity?

It is worth noting that similar studies have been done for many species - from humans to crop plants - and all have found evidence that the daughters of stressed mothers had epigenetic adaptations for a stressful world. For example, the daughters of drought stressed crop plants may be more drought tolerant. They don't grow as well or produce as much, but they survive to breed in drought conditions.

More subtly, adaptation to local growing conditions allows plants and animals to fit in. This isn't adaptation by immigrants, it adaptation by their children. For example, improved seed varieties imported from elsewhere may not perform as well as expected, but if those same varieties are locally grown then the seed produced there may do better.

There are limits, it's not magic, but marginal improvement is one key to success. I've advised the cow calf men that I buy steers from to look to protein supplements for their third trimester gestating cows. Perhaps I'll get steers in future that are better doers though they have the same genetics as in the past.