Bull To Rail

More Bull Doesn't Always Mean More Calf Value

Victoria G Myers
By  Victoria G. Myers , Progressive Farmer Senior Editor
Brangus breeder and commercial herdsman Robert Field says bull selection has to be based on an operation's overall goals.(Progressive Farmer photo by Victoria G. Myers)

Robert Field remembers when commercial cattlemen buying his Brangus bulls were all in the "more" mindset. More cow, more milk, more pounds of weaned calf.

"They'd all say, 'I sell by the pound'. And, they'd want something that would mash that scale down harder," recalls the Shuqualak, Mississippi, breeder.

"I'd tell them then, and it hasn't changed today, the bigger the cow, the more groceries she needs. Without enough groceries, you're going to have more open cows. No one wants to carry a big, open cow through the winter."

Keep Control

There is a way, however, to hang plenty of pounds on the rail without growing behemoth cows, says North Dakota's Kris Ringwall. It comes down to bull management.

The beef specialist at North Dakota State University says while it's true there is a relationship between cow size and carcass size, it's not as stark as cattle producers think. He points to data from herds at the Dickinson Research Extension Center. It was collected all the way through harvest on two sets of calves from two cow herds with average weights close to 300 pounds apart.

One cow herd, designated the "range herd," had smaller, mature cows averaging 1,295 pounds. The other cow herd, the "beef herd," had mature cows averaging 1,522 pounds. Steers from the smaller range herd averaged 1,456 pounds liveweight at harvest (872-pound carcass); those from the beef herd averaged 1,751 pounds (1,050-pound carcass).

What percentage of the cow's weight ended up on the rail? On average, it's about two-thirds the weight of the cow. Ringwall says there was only a 3% difference between the two groups. Range cow steers came in at 112% of the average dam weight (67% as carcass weight), beef cow steers at 115% (69% as carcass weight).

"To stay in a normalized range on carcass weights [600 to 900 pounds], cows weighing 900 to 1,350 pounds fit commercial production," Ringwall explains. "As cow size creeps over 1,400 pounds, heavier carcass weights result, which can trigger discounts depending on current demand and market specifications."

He adds based on results with the Center's cattle they've noted as cows get heavier, increased carcass weights on their calves will likely result in larger rib eyes, less 12th-rib fat and lower marbling scores.

"As cows get lighter, though, the carcasses more likely will have higher marbling scores and large rib-eye area per 100 pounds of body weight," Ringwall says.

For operations that moderate cow size, Ringwall says the inevitable question is about stocking rate. Here's his math: Stock 47 1,100-pound cows, and you'll get about 25,145 pounds of calf produced (7 months). Or, stock 39 1,400-pound cows, and you'll get about 24,921 pounds of calf. That's assuming 100% conception and calving rates.

Keep Frame Size In Moderation

Cattleman Field believes conception rates are almost always going to be better on moderately framed females because it's easier to maintain body condition. He adds moderating frame size is one of the simpler corrections a cattle producer can make, as structural traits are highly heritable.

"The frame score on a bull is going to very much be a predictor of the frame score on that calf, which tells us a lot about overall size," Field says.

Ringwall adds one good way to approach this is by having both a maternal and a terminal bull. This can do a lot to make an operation more efficient.

Select maternal bulls to keep cow size down around 1,300 pounds, he says. Then, on those cows, use terminal bulls. This allows for greater efficiency, he explains.

"I've increased my stocking rate, so more cows are calving. And, by using the right terminal bull, I'm producing a calf that can put on more pounds in the feedyard," Ringwall notes.

For operations where this isn't practical, there are two options. Buy replacement cows with the size and maternal traits important to the operation, and mate to terminal sires able to provide growth. Or, focus the business on breeding good replacement heifers using a bull with the right set of maternal traits.

Heavy On Bulls

Whichever direction an operation leans, Ringwall says the key is to get out of the mindset that "more" is best when it comes to the herd bull. For most commercial cattle producers, it's all about a middle-of-the-road genetic package, he stresses.

In the case of a maternal bull, he advises producers look at six traits when evaluating EPDs: birthweight, weaning weight, yearling weight, milk, marbling and rib eye. Stay around the 50th percentile, he says.

"You don't need to be in the 90th or 100th percentiles on a maternal bull," he explains. "Those kind of EPDs are for your terminal bulls. The EPD values drive where you go with the calf crop. So, if we're talking a terminal bull, more is probably better."

Both Ringwall and Field say the most significant part of bull selection is knowing your operation's goals then making the best decisions to get there.

"When you know those answers, then go out and find EPDs on bulls. The ones that will do what you want maternally will be those in the middle," the specialist says.

Ringwall also suggests using a benchmark on current bulls to help make EPD decisions.

"Base future bull selection on the need to decrease, increase or maintain the average EPD value for the trait you currently have in the herd," he explains. "This is the process of tweaking EPD values to guide future bull purchases and create desired calf performance."

Field echoes the sentiment. He says EPDs have changed the cattle business for the better in his 45 years, and he encourages producers to learn how to use them to improve their herds.

"Really understanding and using EPDs to your advantage can mean so much to commercial cattle producers," he says. "This isn't just about birthweights, although we tend to pay a lot of attention to that. It's about the whole herd and, ultimately, profitability. And, that all comes back around to having the right bull."


As a good as a great bull is, management will be the difference between being an asset or a possible herd liability. Three keys to keeping problems at a minimum:

1. Controlled Calving Seasons. Bulls have a job, and when not contained, they will do it no matter how many gates or fences they have to tear up in the process. This throws the idea of a controlled calving season out the window, not to mention adding to fence-mending time.

Once a breeding season is established, the bull has to be separated from the cow herd; and, in most cases, this involves a high-output electric fence. There is a cost to keeping a bull contained, but there's also an added market and management benefit to a uniform calf crop.

2. Disease Control. Every bull brought onto the farm has to be isolated and checked for disease. Depending on the age of the bull, some reproductive diseases such as trichomoniasis are more or less common. But, any bull, even virgin bulls, can be carriers of something you don't want to be exposed to the rest of the herd.

Mississippi cattleman Robert Field says many bull sales are now held in the fall, giving producers time to find a bull and get back test results for things like Johne's disease and persistent infection bovine viral diarrhea (PI BVD).

It's also important to have a thorough Breeding Soundness Exam done 30 days prior to turning the bull out. If there's a problem, there's still time to replace the bull in a spring sale.

3. Terminal, Maternal Or Both. Inbreeding in small herds can be a problem, so producers have to be careful if running a single-bull herd. In this case, replace the sire every third year.

Another option is to have a strictly terminal herd bull, meaning you buy replacement females from someone else. In larger operations, both a maternal bull and a terminal bull may be an option. This also allows producers to tailor bull EPDs to the herd environment and management program.

Victoria Myers