Eureka! This word is said to have been shouted by excited 1800s gold miners upon finding a large, glittering nugget. "Eureka! Eureka! Eureka!" the miners probably shouted as they raced to the local assay office. But it was at the assay office that many of the miners discovered their nuggets weren't real gold, just fool's gold-only glittering hunks of iron sulfide.

Maybe eureka has been your word when weighing a big calf out of a big cow at weaning time. And maybe you've felt like saying "Eureka!" over your choice of a large, so-called elephant breed over a so-called small breed. But are you sure you have found real gold, not fool's gold?

I told you last month of a project I had undertaken using Cowculator, a computer program developed at Oklahoma State University. The Cowculator program brings together the nutritional requirements of cows under various conditions with the nutritional values and costs of feedstuffs and supplements to calculate annual maintenance costs. The input for Cowculator comes from the National Research Council and other standard references. I can't imagine a better basis anywhere for producing useful information.

Before discussing the accompanying table, let's look at some of the realities of the big cow vs. little cow issue. It is known that there are differences in milk production potential between breeds and within breeds. Various levels of milk production require various levels of energy consumption and costs. For example, the Cowculator program shows greater requirements for a Holstein cow over a British breed cow of the same weight and body condition in the spring grazing season-dry matter intake 5.4 percent higher and acres of forage 10 percent higher. Total costs for this period would be 10 percent greater.

It is generally understood also that energy requirements are greater for cows with high growth potential and organ masses. But these and other peculiarities are built into the Cowculator equations.

It also must be pointed out before discussing the accompanying table that one average-milking breed (Breed A) and one heavy-milking breed (Breed B) were selected for this analysis to illustrate the difference breed choices can make. While these values suffice for the purposes of this analysis, preliminary research shows that examination of the numerous other breeds on the Cowculator list and crosses of these breeds will produce other results.

The obvious implications of the accompanying table are that maintenance costs increase as cow weight increases, regardless of breed, and that these costs were higher for Breed B than for Breed A. These differences can undoubtedly be rationalized by skeptics. For example, couldn't differences of $13 to $19 per cow disappear in the margin for error that's always present in statistics? And, doesn't the cost for Breed B increase less from the bottom to the top than those for Breed A?

Another implication of the accompanying table is that elephant cows exist in both Breed A and Breed B. A trip along any road in cow country would show this. And one cannot look at the accompanying table and say that elephants don't cost more to maintain, regardless of breed. Granted, large cows are more common in Breed B than the Breed A.

For those of you who are poised to point out that pastures cannot carry as many big cows as small cows, you're right. But this has no effect on per-cow costs because it is automatically factored into the Cowculator equations. Reduced carrying capacity of a given acreage, however, affects profits, which will be discussed next month.

Remember, this is only column two of my three column series. To this point, we have only dealt with background information and maintenance costs. We will deal with net income in next month's column. So, if you'd really like to know whether those large calves out of large cows are real gold or fool's gold, be a reader.

To contact Fred Knop, write Drovers or send e-mail to: fredlyn@aol.com