Like a calf, I tend to think of optimum milk as whole milk with all the cream. (Unlike a calf, I like mine ice-cold!) But a common fallacy among status-quo producers is that optimum milk is an environment-specific concept. The basic idea is that lush, productive environments demand larger, heavy-milking cows because they are better able to increase their weaning weights.
A recent ONA Report out of the University of Florida found that increasing milk production from 8 lbs/day to 24 lbs/day in 900 lb cows is associated with a 70% increase in weaning weights, whereas the same milk increase in 1300 lb cows is associated with only a 58% increase in weaning weights. Although this study was conducted in a high-input feed environment that included molasses and cottonseed meal supplementation, an interesting trend is evident – increasing milk production in smaller cattle has relatively more impact. And as for needing larger cows to take advantage of lush feed – all you Herd Quitters are already thinking about increasing the stocking rate with right-sized cattle, aren’t you?
But back to milk production, we know that maximum is not optimum. So what is optimum milk production? Kit Pharo, Johann Zietsman and others remind us that optimum milk is a balance point between fertility and production. We don’t need to be academics to figure out how to select the right cows…optimum milk is produced when a cow weans a calf that is a respectable percentage of her body weight and is still in good enough condition to breed back year after year. With the right genetics, cows can do this without high-input energy supplements!