Last month I wrote about heifer development, suggesting methods different from those typically used. I have since been wondering about the bulls used by most ranchers who produce their own replacement heifers. Are those bulls “undoing” most of what the producer is trying to accomplish with his heifer development and selection practices?
Looking back into my own history of cattle breeding, I have become convinced that most of us ranchers have been using terminal matings across our entire herd, except for heifers, since the early 70s when the continental breeds started to arrive in the U.S. It was an easy way to get a nice increase in weaning weight.
At about the same time, progeny testing was becoming popular and many of us got caught up in a race for higher and higher weaning weights which was further facilitated by the advent of EPDs. We did get higher weaning weights because we could always find a bull with a little more growth.
We were making terminal matings. The problem was that we weren’t doing terminal marketing. We were keeping those heifer calves as replacement heifers. So, cow size and milk production kept increasing. And stocking rate was decreasing or purchased feed was increasing.
I see no problem with ranchers deciding to use only terminal matings if they sell all of their calves—steers and heifers. In fact, I think many producers would be well advised to do exactly that.
It is easy to find good bulls for terminal matings. Current EPDs lend themselves well to selection for growth and carcass traits. I know a good number of breeders who buy replacement cows, make terminal matings and sell all of the calves.
The cows are just cows—nothing special. But the calves have a great potential for growth and carcass performance. They are nicely profitable. What if the cows were something special—coming from well-developed maternal herds?
Now, where are the bulls for the maternal breeders who are making their own replacement heifers, perhaps with the idea of having some bred cows to sell? These bulls are difficult to find.
Most of the EPDs available are not for maternal traits except as limiters—reducing cow size and milk, keeping growth in a moderate range, balancing maternal calving ease and calving ease direct, etc. Moderation of size, milk, growth and muscle seem to make better long-term mother cows.
The use of selection indices has some appeal. But when “supposed” strength in one trait can compensate for “supposed” weakness in another trait, what is an acceptable balance? When does high growth cause reduction in fertility or increase cow size (reduce stocking rate) in the next generation? At what level should milk production become a negative in the index?
I have asked a number of seedstock breeders those questions and only one had an answer; and I thought his level was too high—purely a guess on my part. What about epigenetic effects? This happens when environmental factors turn on or off (or possibly modify) gene effects. How much of that is heritable or not heritable?
While I like to get aggressive in the use of EPDs for terminal sire selection, for reasons cited, I am much more cautious in the use of EPDs to select bulls for maternal herds. “Moderate” needs to be defined for your ranch, but the range around “your moderate” cannot be too large for any trait.
Cows must become adapted to your environment and then be adaptable to year-to-year variation. Nature will tell you which cows to cull and which bulls to select; but you need to recognize which ones they are.
There are some physical traits that are important such as udder quality, ability to move and travel, ability to maintain body condition on grazed feed with minimal supplementation, feed intake capacity, etc.
Beyond these, I am reminded of a statement heard many years ago—“We need to quit telling cattle what to look like and, instead, tell them what we want them to do and then let them look the way they need to look in order to do what we want them to do.” Remember, we can’t ask them to do more than the environment will provide for and allow.
I think there are a few people who have learned what cows need to look like, but most of us don’t have that skill except for the very obvious. So, how do you choose a bull for maternal matings?
First, the bull must be born in the first 25 days of the calving season—ideally a result of first cycle conception. Then I like to know as much as possible about closely related females. What about their udders, what is their mobility, how about disposition, how long are they staying in the cow herd, what kind of calves do they produce, are they always healthy, etc.?
Fertility and longevity along with the ability to produce an acceptable calf are really what we are looking for in good cows. Bulls that make that kind of cow are hard to find. Bulls that make the good cows usually come from good cow families—dams, grand-dams, sisters, and daughters are almost all good.
I think that is the reason that a good number of successful commercial ranchers are producing their own bulls. They select bulls from their adapted cows that have always calved in the first cycle. The cow must have calved as a two-year-old and again as a three-year-old before a bull can be kept.
The bulls must have good weight in relationship to hip height at one year of age. They must pass a BSE at a year of age after minimal development. A few breeders are breeding their yearling heifers to their yearling bulls—only yearling bulls—then using DNA for parentage to know which bulls sired the most calves. That ought to check for a combination of fertility, libido and structural soundness at a young age.
To have a good maternal cow herd you must use bulls that are highly fertile, structurally sound, that will produce calves that have good growth (not outstanding) and are acceptable in the marketplace.