by: Stephen B. Blezinger
Ph.D., PAS

Every year about this time many producers are busy looking for replacement bulls to go into their cow herds. As most producers know, every bull, at some point in time has to be replaced due to age, injury, reproductive unsoundness or because that bull no longer fits the program. In order to insure that a bull maximizes his productive life it is important to effectively manage that animal. Of this, feeding and nutrition is very important. Nutritional considerations for getting and keeping herd bulls in top performance condition has been discussed repeatedly by many nutritional and reproductive experts. Despite this, however, many producers will neglect, albeit not intentionally, the nutrition and management of their bulls or will feed them similarly to the rest of their herd. After all, compared to the number of cows that you own, you only have a few bulls. One thing to remember, however, is that your bulls make up 50 percent of your calf crop from the group of cows they are on. In other words, these very few individuals have a tremendous impact on your overall herd performance. If not fed and managed properly, they can also create some serious problems.

Since nutritional management of mature bulls has been discussed fairly extensively, let's look at another aspect of the bull program, that of growth and development. In many purebred operations, bull sales make up a significant portion of their cash flow. Therefore, bull growth and development is very important to the overall success of their operation. Many cattlemen who produce bulls spend a great amount of time on the genetics they use and their breeding operation. Remember that this genetic potential can never be realized if these animals are not fed properly.

Consider for a minute what you look for in a herd bull:

1) Genetically, you want an animal with EPD's that will improve the quality of your calf crop and long-term improve your overall herd. This may mean potential to improve weaning weights, yearling weights, average daily gains, milking ability, maternal characteristic and so on.

2) Physically and physiologically, you look for an animal that is well developed in both muscle and skeletal structure, not excessively fat, sound on his feet and legs, excellent libido, appropriate sperm count and semen quality. If this bull is used as the foundation of your breeding program he must possess good size, conformation and eye appeal. Remember that when potential buyers are looking at your cattle and are considering purchasing your cattle to add to their herds they will be looking at your bull and overall visual appraisal plays a tremendous role in making the sale. Developing all these characteristics in mature bulls begins before birth by choosing the right combination of genetics and after birth by how we feed and manage these growing animals.

One of the first things we need to point out is that each breed is different. Feeding program design will be substantially different between breeds. This must be taken into account when we are deciding what, how and how much we are to feed growing bulls. This becomes especially apparent as young cattle reach weaning age.

Birth to Weaning

During this period of time, young bulls receive most of their nutritional needs from milk. This changes as they get a bit older and start to graze and consume hay. My recommendation to my clients has been to utilize the best quality forage that can be acquired either by production or purchase at an economically feasible price. This will benefit not only the mature brood cows but also the calves as they start to nibble on roughages and as this material becomes the predominant component in their diet. Forages harvested in a timely fashion (possessing good digestibility) and containing better than average protein and other nutrient contents are much better suited to use by younger cattle. In addition to milk and quality forages, creeping young calves can also be helpful to accelerate their growth and development. Feeding two to four pounds of a well designed creep ration can greatly improve skeletal and muscle development in pre-weaning calves. The exact type of creep feed will depend on a number of factors. If the forages being fed are good quality, as discussed above, a greater emphasis on energy is important and less on protein content. The difference here might be between using a creep containing 14 or 16 percent protein. If forage quality is good, use of a lower protein creep can be cost effective and get more energy into calves. If forages are marginal to average, use a higher protein creep feed to insure that protein needs are met. A creep feed of this nature should contain no more than 12 to 15 percent fiber and carry a full complement of vitamins and minerals. Depending on your situation, you may need to purchase this feed commercially or if you have your own mixing capabilities, put together the necessary ingredients to develop a well balanced creep. It is essential that consumption of a feed of this nature is carefully monitored and controlled. Young cattle over-consuming feeds of this type can scour or become excessively fat at an early age, neither of which is desirable and will have negative effects on performance. Creep feeding young bulls can add structural size and increase body weight at weaning and will put these animals one step closer to rapid development.

Weaning to Maturity

A producer needs to accomplish with the feeding of weaned bulls is to develop a sound skeletal and muscle structure. A lot of debate constantly goes on about how to do this and we need to discuss some things regarding this process and the end product. One of the best ways to develop bulls is on a strong forage based program. Bulls fed a high concentrate diet, that is, primarily a grain and protein meal diet with only minor amounts of roughage added tend to be too fat at maturity and also may not have the necessary digestive capacity to perform well when put into a breeding or range situation. Many examples have been seen of a buyer purchasing a bull at a sale where the bull had been developed on a high concentrate diet. They then took this bull home and put him with a group of females only to have him “fall apart” after only a short period of time. Falling apart means to lose excessive amount of weight, have no energy and subsequently be unable to perform as necessary. An example of this happened to an acquaintance a number of years ago in extreme. This breeder had a bull he was showing quite extensively and to handle the show and travel schedule was obviously feeding him a high energy, high protein feed. When the bull's show career was over, this breeder put him into a pasture with a group of cows, receiving hay and a little supplement. This bull actually died from the stress of the dietary and environmental change. Bulls developed a bit more slowly on a high roughage ration will have a greater rumen capacity and will make the change from the growth/development stage to the breeding stage much more easily.

Depending on your actual goals, growing and developing bulls should gain 2.5 pound per head per day minimum. Initially they need to consume a total ration which contains approximately 14 pecent protein on a dry matter basis. This protein intake can be reduced gradually as these bulls grow and mature. A mature bull with a body weight of 1,800 pounds or more actually requires a total ration containing no more than 10 to 11 percent protein. The table below shows some of the nutrient needs for medium frame-sized bulls gaining 2.5 pounds per day at varying body weights. Remember, these numbers will be different for large framed or more heavily muscled breeds.

Weight      Dry Matter intake      %Protein    %TDN       Nem*     Neg*     %Ca     %P

  600                  15.0                      14.00           70.0         .76        .48         .55      .32
  700                  16.8                      13.00           70.0         .76        .48         .50      .30
  800                  18.6                      12.00           70.0         .76        .48         .48      .28
  900                  20.3                      11.00           70.0         .76        .48         .45      .26
1000                  22.0                      10.75           70.0         .76        .48         .41      .24
1100                  23.6                      10.50           70.0         .76        .48         .38      .24
1200                  25.7                      10.50           70.0         .76        .48         .35      .24

*Megacalories per pound of ration

You will notice that energy concentration stays the came as the cattle get larger. Energy intake is primarily controlled through actual amounts of feed consumed. As they get larger they eat more and therefore consume more calories. These bulls need to also be fed or have access to a full regime of vitamins and minerals to meet those needs but that's another article entirely.

As discussed before, ideally, to produce and bull that will perform once put into the breeding program he should be fed as much roughage as possible while meeting the above requirements during the growth and development phase.

One last recommendation for feeding young bulls is to pen or group bulls according to their body size. Mixing large and small bulls can have a negative effect on the smaller cattle because of pecking order development. If your lots or pastures are fairly small and feeding space is limited a larger more aggressive bull will prevent a younger, weaker animal from eating as it needs to.

Remember that when designing a nutritional program for developing bulls you must keep your end product or end result in mind. Proper feeding and management can produce structurally sound, active bulls which will really do the job for you.

Dr. Steve Blezinger is and nutritional and management consultant with an office in Sulphur Springs Texas. He can be reached by phone at (903) 352-3475 or by e-mail at [email protected]

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