COLUMNS: Big cow, little cow – does size really matter?

There have been a lot of studies trying to calculate whether the size of a mother cow makes a difference.

There have been a lot of studies trying to calculate whether the size of a mother cow makes a difference to the profitability of the ranch operation.

From my reading it seems that the bigger the cow, the smaller the relative size of the calf.  Conversely a smaller cow weans a calf, which is relatively bigger as a percentage of the mother’s size, than the calves of the bigger cows.

Larger cows wean more pounds each, but running more, smaller cows, on the same amount of land probably means more pounds of calves.

They may be smaller calves but then the price per pound of smaller calves has been higher.

One measure is how many pounds of calves are weaned and ready for sale on the same land and feed base as the larger cows. Then you have to account for the higher price for the smaller calves.

On open range a cow unit (Animal unit Month, AUM)  is based on a 1000 pound cow, but you can run 1,300 to 1,400-pound cows and pay the roughly $3 per AUM. But once on private pasture or your own hay this advantage is not there.

It is cheaper to run the larger cows on open range than it is the smaller ones. So this needs to be taken into account. But pasture rates are not the big item.

Private pasture costs about $15-30 per animal per month, usually closer to $18.

So, over six months, it might cost $70 more on private land to keep that cow on private versus the public pasture.

Bigger cows are economically more efficient during the summer pasturing time because they bring in more pounds of calves at a lower cost.

But something like 60 per cent of the cost of keeping a cow is in the winter feeding, so the real test is what is the profit per acre of land or per pound of feed.

Here is where the smaller cows appear to shine.

While some studies say larger cows are more efficient at feed conversion. Most studies say the opposite.

One recent study at the University of Wyoming shows the big cow ranch (similar to B.C.s average size) had a four year average of $139,000 gross income, whereas the small cow ranch produced $173,000.

Another study from Auburn University concluded: “the cost of the extra feed required maintaining the heavier cows for a year will not be offset by the additional pounds of calf produced and their market value.”

Conclusion from the Auburn study: “Don’t let your cows get too large. Smaller cows are more efficient with their feed usage than larger cows.”

There needs to more data from operations here so we know our facts but research from away points to needing smaller cows but more of them on the same land base is the way to go.

The real consideration is what is the cost per pound on your operation.  Calculation input costs and depreciation on the cows is also important. Some suggest smaller cows live longer and produce more calves over their lifetime.

Others may differ in their opinion. Perhaps the secret to success is to find cows from your own place or from somewhere else that fit your particular environment.

David Zirnhelt is a member of the Cariboo Cattlemen’s Association and chair of the advisory committee for the Applied Sustainable Ranching program which started at Thompson Rivers University in Williams Lake this January.