Don't Buy a Bull on One Number

I have watched this movie several times. A man goes to the sale with one thing on his mind. Birth weight, or growth, or marbling, or milk. He buys the top bull for that trait and he is pleased with himself for three years. Then the daughters start coming into the herd, and he finds out what he gave up to get it.

How a herd gets lopsided

Traits in cattle are tied together. You pull on one and the others move. Chase growth hard and you get bigger cows that eat more and often bigger calves at birth. Chase milk and you get cows that need more feed, and on thin grass they run down and miss breeding. Chase calving ease alone and you can end up with calves that do not grow or grade. Meanwhile none of it matters if the cow does not breed back.

The feed side shows the same thing. The Angus Journal warns that animals eating less but growing slower may not be the most productive (Angus Journal). Pick the lowest intake bull and you may get exactly that calf.

What the indexes are for

The American Angus Association puts out dollar indexes so you do not have to juggle thirty numbers. The list includes $M for maternal weaned calf value, $W for weaned calf value, $F for feedlot value, $G for grid value, $B for beef value and $C for a combined figure (Association data descriptions). Each rolls several EPDs into dollars per head.

They help. They are not gospel. Each one is built on assumptions about prices and how the cattle are raised and sold. A man selling light calves off grass and a man feeding cattle to a grid do not want the same bull. Pick the index that looks like your operation and use it to rank.

How I would buy

1. Write down where your calves go. Weaning, backgrounding, your own feedlot, a freezer trade. Everything starts there.
2. Set pass-fail lines. Feet, fertility, temperament and calving ease for heifer bulls. If he fails one, he is out. Do not argue with yourself about it.
3. Rank what is left with the index that matches your market.
4. Put ceilings on the traits that can run away: birth weight, mature size, milk. Set them to what your grass can carry.
5. Buy more than one bull when you can. EPDs are estimates, and one bad guess should not cost you the whole herd.

Our bull buying checklist covers the rest, including the physical exam. And once the bull is home, bull care all year keeps him working.

The sale barn trap

Sale day is when this goes wrong. A good auctioneer and a loud crowd make a man bid on the bull everybody else wants, and the catalog page for that bull usually shouts about one number. Go in with your pass-fail lines already written on paper. When the bidding gets hot, you will have something to hold you steady. A bull that does not meet your list is not a bargain at any price. If none of the bulls on the sale meet your list, go home and buy later or buy private treaty. There is always another sale, and a bad bull is a ten-year mistake.

What about proven sires

A bull with accurate numbers and a record of daughters in real herds takes some of the guessing out. You pay more, and you get fewer surprises. Young bulls with low-accuracy numbers can be great or can be a gamble. If you take the gamble, take it on a bull you can cheaply replace, and not on the one that will breed your whole heifer crop.

Keep score yourself

EPDs are a forecast. Your herd is the result. Write down weaning weights adjusted for age, how many cows calved in the first three weeks, how many bred back, and how long your cows last. If one of those is sliding, change the mix. Do not swing hard the other way. Overcorrecting is how you end up with the opposite problem. The University of Nebraska beef program has solid, plain material on selection if you want a second opinion.

What DNA testing changes

Genomic testing makes the numbers more accurate, especially on young bulls. The Association reported that in fiscal year 2025, 75 percent of registered animals were genomically tested. That means the numbers behind the indexes are getting better. It does not change the rule. A sharper estimate of a lopsided bull is still a lopsided bull.

Think about the person who eats it

At the end of the road there is a steak and a buyer who wants it to eat the same every time. Programs like Certified Angus Beef pay for carcass quality, but your cows have to stay sound and breed back for you to be around to collect. Balance pays because it keeps every part of the operation working. For more on how breeding decisions play out, check farm.fm's page on artificial selection, and the agriculture directory can point you to seedstock outfits near you.

Index definitions and weights change, so check the current Association documents before you bid. This site is independent and not affiliated with the Association or Certified Angus Beef.