RADIO TRANSCRIPT
Damon Pollard
November 22, 2024

This is Damon Pollard, Livestock Agent with the North Carolina
Cooperative Extension Service-Burke Center. Today’s topic is the Impact of
Cow Size on Nutrient Needs.

Cattle producers are constantly working on getting ready for winter, and
although hay supplies may seem adequate, some may find they didn’t plan
correctly. In planning for the winter feed supply, producers need to
understand nutrient needs for different body size.

Nutrient needs for cows of different body weights are not the same.
Cows that weigh 1,300 pounds have greater nutrient requirements, compared
to cows that weigh 1,000 pounds. If a 1,000-pound cow and a 1,300-pound
cow are grazing the same forage resource, the 1,300-pound cow will need to
consume more of that forage to meet her requirements. Maintenance feed
intake is proportional to metabolic body weight, which is described as body
weight to the 3/4 power (body wt.3/4). Metabolic body weight isn't just the
weight of the animal, but also describes the surface area of the animal.
Heavier cows eat more feed to meet their requirements. The question is: how
much more do heavier cows eat?? Data suggests that for each 10% increase
in body weight, there is not a 10% increase in maintenance feed intake. The
data suggests about a 7% increase in feed intake for each 10% increase in
live weight. A 1,300-pound cow is will consume 22% more feed than the
1,000-pound female although there is a 30% difference in body weight.

Keep these thoughts in mind when planning for the winter ahead, so
that your cattle will be able to meet their nutrient requirements.
This is Damon Pollard, Livestock Agent with the North Carolina
Cooperative Extension Service-Burke Center. If you would like more
information, call us at 828-764-9480.