The old saying "Cows are creatures of habit" has a lot of truth. Unfortunately, it inevitably runs into another old saying that has a lot of truth, too: "Change is the only constant in life."
Despite widespread dairy producer belief that ration consistency is important, William Weiss, professor of animal sciences at The Ohio State University, says almost no research has been done to measure how much nutrient variation exists and what effect it has on production.
This prompted him and colleagues at OSU to collaborate with nutritionists and dairy owners in the region on a large project to learn more about the extent of both. What they learned surprised them, which Weiss summarizes in four points:
- 1. On individual farms, average variation in nutrient composition of common forages and some concentrate feeds is significant.
- 2. Variations are even greater between farms, which emphasizes the need for each farm to develop sampling procedures that are specific for it.
- 3. About 60 percent of day-to-day variation in corn and hay silage is due to sampling and testing errors. This means producers should not rely on results from a single sample and should formulate diets based upon at least three samples.
- 4. Cows seem to be able to handle significant day-to-day variation in nutrient composition of total diets, as long as they have adequate extra feed available and unbalanced diets are not fed for more than a few days.
