Cattle Today

Cattle Today



by: Dr. Glenn Selk
Oklahoma State University, Reproductive Specialist

The drought continues to cause concern about which cows to sell and which to keep. Of course feed and water supplies for the cowherd are huge concerns. However, we must still keep in mind that half of the herd's genetics and half of the fertility is penned up in the bull pasture. Therefore, it is important to remember to take good care of the bull battery during the drought.

After the breeding season, bulls become a necessary evil or unwelcome visitor. Many producers might like to forget about them for the balance of the year and some almost do. While it is true that bulls during the post breeding season don't require much management, adequate planning and care can help ensure that bull costs will be kept within reason and that bulls will be ready to go again the next time they are needed.

In most spring calving herds, the breeding season will commence in the spring or early summer and extend for two to three months. If a 60 day prebreeding conditioning period is allowed, this leaves a post breeding season of about seven months, usually coming in the fall and winter. Goals for this period are basically as follows: Keep feed costs at a practical minimum, BUT keep the bulls in moderate condition and allow growth of young bulls.

Post Breeding Appraisal: As bulls come out of the breeding pasture, one of the first steps should be to appraise the bull battery and sort them three ways. The largest group should be the mature bulls in good condition.

Perhaps the most important group is the young bulls that are still growing and need higher quality feed. Bulls that are extremely thin or need special care for other reasons can be placed in this group as well. The last group is for old or crippled bulls that have completed their productive life and are to be marketed.

All bulls should have access at all times to a high quality mineral mix. Phosphorus is a critical mineral for successful reproduction and is not present in adequate amounts in dry or low quality, harvested forage. A good source of supplemental phosphorus is dicalcium phosphate ("dical"). "Dical" can be mixed with trace mineralized salt in equal parts or two parts salt to one part mineral. Many excellent commercial mineral mixes are available at feed suppliers.

Vitamin A nutrition also is important to the resting bull. Natural sources are green growing plants or high quality hay with good green color. However, with many pastures drought stressed and nearly dormant, vitamin A can be limiting for bulls just as it is for the cowherd.

Supplemental vitamin A can be added to the mineral mix or fed with a supplement. It can also be administered in the form of an injection once every three to four months. Visit with your veterinarian about injectable vitamin A. Some products (on very rare occasions) have caused adverse reactions.

Mature bulls in good condition can exist very well on an essentially all roughage diet. While the amount will vary some with the size of the cattle, a good rule to remember is about two percent of their body weight in dry feed per day. Protein needs will parallel closely those of a dry, pregnant mature cow in the middle third of gestation, so it can be supplemented as needed. If adequate grass hay or standing grass is available free choice, the mature bull will maintain condition with 3 to 4 lbs. per day of a high (40 percent) protein supplement.

In situations where forage is extremely scarce, limit feeding of concentrates may be used. Remember bulls can founder if given too much grain too quickly. A gradual increase in grain intake will help reduce the risk of acidosis.

Young bulls need to grow, and in some cases regain, body condition. This means that at least half of their diet will be a concentrate feed that contains enough crude protein to meet their needs.

As a rule of thumb, young (yearling to two year olds) need their total diet to contain 12 percent crude protein. Therefore testing the hay will help to determine what protein percentage is necessary in the grain portion of their feed.

In the day to day battle to take care of the cows during the drought, don't forget the bulls.


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