Producer Questions prior to 2009 Bull Management

Bull Management

(Producer Questions prior to 2009)

What is the best method of castrating a bull calf? And when is the best time to do it?

There seems to be several times that bull calves are castrated; at birth, at branding time and before the time that they and their dam are moved to spring/summer pasture, at weaning, and, sometimes in the seedstock business, after weaning. There is probably some debate when the "best" time to castrate, but whatever the time, make sure it is done to avoid infection and stress is as minimal as possible.

The time when it seems that there is the least amount of stress is when castration is done at birth. Usually the procedure is using a rubber band that fits tightly around the scrotum and next to the body. The blood supply to the scrotum and the two testicles in the scrotum are stopped and necrosis occurs and, after about a month, the testicles and scrotum fall off. The key at this age is to make sure both testicles have descended and are in the scrotum before the band is put on.

As the animal gets older there is probably more stress and care must be taken because as the animal matures the blood supply to the testicles increases as well as an increase in nerve development. Usually banding is the method used when castrating at birth and for bulls that are older, especially after weaning has occurred. A scalpel is used at most of the other times. When a bull calf is castrated, take sure he has access to a clean area and that the flies are controlled to minimize the risk of infection.

How do they determine milk EPD's on bulls?

Genetic estimates for milk production for beef bulls are usually cited as Milk EPD's or Maternal Milk EPD's. EPD is the acronym for Expected Progeny Difference or a measure of the transmitted genetic effect of a sire or dam. Obviously, beef cows are not milked, so there is no direct measure of milk production. However, because a major share of weaning weight is due to milk production, weaning weight differences can be used to estimate the "pounds of weaning weight due to milk". Thus, milk EPD's estimate the pounds of weaning weight due to milk, not the pounds of milk produced by a bull's daughters. When a bull is 4 1/2 years old his daughters wean their first calves and the milk EPD can be estimated with some degree of accuracy.

The "direct" genetic effect of a bull on weight of his progeny can be separated from his "maternal" genetic effect on the weight of his grand-progeny (through his daughter's milk). Thanks to large, sophisticated computers this separation of the direct and maternal effects allow for reasonably accurate estimates of milking ability. These estimates are much more accurate in older bulls that have daughters in production, but Milk EPD's can be made from pedigree estimation for yearling bulls (and yearling heifers).

All the major beef breeds publish EPD's for Milk or Maternal Milk in their sire evaluation reports.

What are the do's and don'ts of breeding a bull to his daughter, mother, granddaughter, or sister?

Mating any of the above would result in a high level of inbreeding. Generally speaking, inbreeding of this nature should be avoided. Inbreeding increases the pairing of similar genes, or increases the number of homozygosis genes. Although this can lead to animals that are more uniform, it has also shown to decrease performance and can potentially lead to reproductive problems in the corresponding offspring. One of the major concerns with a mating such as these is the potential for genetic abnormalities. For instance, if a sire is a carrier for a genetic defect and is then mated to a group of his daughters there is a possibility that some of the calves produced from this mating will display the genetic defect. In practice, a mating of this kind are used to determine if a sire is a carrier of a genetic defect in the absence of any kind of DNA test but in commercial production settings the mating of close relatives would not be desirable.

I winter the bulls and I was wondering how much to feed them. They have free choice of hay alfalfa grass mix and corn. They are going to be 2 yr old in the spring. How much corn should I feed them?

Feeding bulls in the winter can be pretty simple, but don't forget to get them in their working clothes before turning them out to breed cows. Pay special attention to young bulls as they are usually still growing after using them as yearlings in their first breeding season. If you are using them in the spring, give them plenty of area in the winter to exercise and if there is a fight, the young or less dominant bull(s) have a chance to get away. I also suggest that if you have plenty of area in the winter (a pasture), to manage all bulls as a group and this will avoid major fighting during the breeding season. If you buy new bulls introduce them with caution so as they don't get hurt. I like to start early getting bulls back into shape for the next breeding season. This is especially beneficial for young bulls that have completed their first breeding season. I like to see bulls in a body condition score of 5 to 6 at least 30 days before the start of the next breeding season.

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 harvested forage. Good sources of supplemental phosphorus are monocalcium phosphate or dicalcium phosphate. These can be mixed with trace mineral salt in equal parts or two parts salt to one part mineral. Vitamin A nutrition also is important to the resting bull. Natural sources are green growing plants or high-quality hay with good green color. Supplemental vitamin A can be added to the mineral mix or fed with a supplement.

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 2 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. Extra care and feed of yearling bulls after the breeding season will result in stronger, more attractive mature bulls. A two-year-old bull will probably need to gain 1 pound per day if he has developed properly to this stage in his life.

These bulls may need 35 pounds of feed or more, of which 8 to 12 pounds should be grain. If body condition is at a BCS of 5 or below, the amount of grain will need to be increased to near 1 pound or ore per 100 pounds of body weight. Again make any increases in grain intake gradually so that digestive disorders are unlikely. Continue to monitor the total protein content of the diet and keep the concentration of crude protein near 12%. Depending on the forage available this again may require protein supplements may be included in the grain mix. Monitor the body condition of the bulls closely and make grain feeding adjustments to reach the body condition score of "6" before the next breeding season begins. This is critical if the bulls will be used once again in a fall breeding season. It won't hurt the mature bulls to get some grain, but do not over-condition the bulls and get them fat or founder the bulls.

Bulls can be fed in a bunk, but there needs to be at least 36 to 40 inches per bull and plenty of bunk space so that the dominant bull(s) doesn't over-eat. Some producers will put grain into their cake feeder and put the grain on the ground in different spots for the number of bulls that are in the pasture. They have a good idea what a pile of 10 pounds of grain on the ground looks like.

Corn grain and alfalfa with some grass hay would work well. With good quality alfalfa, I don't think you will any other protein source. Salt and mineral are important, but that can be free-choice.