Bringing Home A Young Bull

It is that time of year when ranchers are traveling the countryside trying to get the bull power that they will need for the upcoming breeding season. In scanning the bull catalogs and sitting through some sales over the past few weeks I have begun to ask myself a question. Are there more yearling bulls on the market these days? That has been a gradual trend for several years now and it only makes sense that with this year’s higher feed costs that bull producers might consider it more economical to sell yearling bulls as opposed to feeding them out to be two year olds.

What does that mean to you, as a yearling bull buyer? For starters, the yearling bull may be less expensive to purchase than an older bull. Secondly, the purchase of a younger bull gives you the potential opportunity to get an extra calf crop out of this sire before his breeding abilities begin to decline around 5 or 6 years of age.

On the other hand, you have just invested in an immature sire that is going to need some special attention between now and breeding season. For that matter, that special attention is going to need to continue for the next year.

It is good to find out what the ration is that your new bull has been on and try to have something similar when the bull arrives at your place. Major changes in diet can cause a number of metabolic challenges that can inhibit growth, reproductive functions, and sperm development. Make any changes to the diet gradually and over time. If the young bull is excessively fat, you may want to back him down before entering into the cow herd. Research has shown that excessively fat bulls can have lowered fertility and a poor libido (will or interest to mate). Yet, you do not want the young bull to be skinny either. First, he is a growing animal that is still developing and you do not want to do anything that is going to restrict that growth. Secondly, the bull needs to have a little bit of fat reserve to help him through the breeding season. A working bull will expend more energy mating than what he will take in. You can expect a yearling bull to lose 100 to 300 pounds during a 60-day breeding period. That weight loss needs to be coming from fat reserves rather than atrophy of the muscle tissue.

Maintaining proper growth on the young bull under 12 months of age means that he should be gaining about 2.5 to 3 pounds per day when not with the cows. In many cases, this can be achieved by feeding a ration that is 13 to 14 percent crude protein (CP) and 65 to 70 percent total digestible nutrients (TDN) at 1 percent of body weight per day. So a 600 pound calf would receive 6 pounds of this ration; a 900 pound calf would get 9 pounds. The young bull that is over 12 months of age will still need to be growing at about 2 pounds per day. Researchers suggest that for this calf you can back the ration down to 10 to 11 percent CP and 60 to 70 percent TDN. It is also important to ensure that these bulls have fresh, clean water. A lack of enough water will limit their feed intake and subsequently limit their growth. Also, urinary calculi are more likely to be a problem when water is in short supply. Additionally, a quality mineral program is essential for the growing bull. In that mineral program, zinc has been proven as a key element for male fertility. The NRC recommends that a bull receive 30 parts per million (ppm) of zinc in the diet. However, some researchers are beginning to question if that is enough for the growing bull and are suggesting 60 ppm.

The pen that you place the young bull in is very important. The bull needs to be able to get exercise and stay fit. This will help them prepare for the breeding season. An area of about two acres is recommended. If this area is long and narrow, that will give more “line distance” for the young bull to exercise in. You can further encourage exercise by having feed, water, and mineral placement at different locations within the pen. The pen should be kept dry and free of mud and manure packs. You want the bull to have good footing and a desire to move about. Another pen feature should be company. Cattle are gregarious and they do better if they have a “buddy”. This can be a steer, pregnant cow, or other bulls. But remember, if you put your new, growing bull in with the old bull battery, he is apt to get beat on quite a bit and he may not get his much needed ration of feed. On the other hand, if he is going to be pastured with other bulls, it is good for them to establish their pecking order before you put them out to pasture with the cows.

When you do get ready to turn that young bull out to pasture you will want to adapt him to grass over 7 to 10 days. As mentioned earlier, sudden changes in the diet can interfere with digestion, metabolism, and reproduction. It will take time for the reticulo-ruminal microorganism population to convert over to a primarily grass diet. If you do something that interferes with your bull’s sperm inventory when he enters the pasture, it will take about 60 days for new sperm to develop. Additionally, depending on the bull, you may want to consider feeding him a little something in the pasture to maintain his growth.

Once your young bull is in the pasture you need to keep in mind that he is just that, a young bull. He may not have reached full puberty and this may cause him to not breed your cows. Also, don’t expect him to be able to breed as many cows as what an older bull might. Many producers who use yearling bulls will put two young bulls out for every older bull that they might have used otherwise. Another consideration is that the young bull is not going to be able to keep up his performance for as long as an older bull. It is recommended that young bulls be used for 45 to 60 days and then given a period of rest to restore their energy reserves, their sperm count, and their libido.

I know that it sounds like I have listed a lot of negatives about purchasing young bulls. However, I think that they offer some strong economic opportunities for the rancher. Yet, they do require some added management to prepare them for both the current and future breeding seasons. If you wish to discuss this subject further, Michael Fisher can be reached through the Yuma County Extension office at 970-332-4151 or by e-mail at mj.fisher@colostate.edu.