Maximizing Fall and Winter Grazing of Beef Cows and Stocker Cattle

Bulletin 872-98

Planning a Supplementation Program

Estimating Intake

In the case of gestating beef cows grazing winter stockpiled fescue or eating poor quality hay, there becomes a problem of how much the rumen can physically hold. A thumb of rule is that the maximum NDF dry matter content of the dry matter of the daily ration can only be 1.2 to 1.5% of the cow's body weight. The higher the quality of the forage, the closer to the top end of the range (1.5% NDF) can be consumed. The poorer the quality of the forage, the closer to the bottom end of the range (1.2% NDF) may be consumed. For example, a 1,200-pound gestating beef cow may be able to consume and digest enough of a 60% NDF forage to meet her daily needs. Assuming a 1.5% NDF capacity, she could eat 30 pounds of this forage dry matter (2.5% of body weight) and contain 18 pounds of NDF dry matter. This would be her physical limit. Increased nutrition needs brought about by severe weather or early lactation must be supplemented by a more digestible feed source of simply providing a higher-quality (lower in NDF) forage.