Practical Bull Management

Your bulls are the most important animals on your cattle farm, making up only 3-4% of your herd but contributing 50% to every calf they produce. A single bull can produce 40 or more calves per year.

ZAM 12-104

The new bull on your farm

  1. If the new bull is transported with other foreign bulls, it would be ideal not to load them into the same compartment on the truck, particularly if free standing. They can get into nasty fights on the truck and lesser bulls cannot escape from the fighters. Therefore, preferably load foreign bulls in separate compartments (even bulls that know one another).
  2. Make sure that the bull (particularly if it is the only one) is offloaded in a safe camp (with sturdy fencing) with one or two other cattle to keep him company for the first few days. Clean water and good grazing will immediately calm him. Make sure he finds the water and leave him in peace for at least two days.
  3. You can take out limited or comprehensive insurance cover and/or you can collect the bull’s semen if it is genetically superior. If you introduce bulls from a disease-free area to an area with endemic diseases such as heart-water, red-water, gall-sickness, etc. rather insure the bull comprehensively for a year.
  4. Incorporate the bull into your normal dipping, dosing and vaccination programme immediately, independently of what the previous owner did.
  5. If the bull is very fat, wean him off concentrated feeds systematically.       In the first week: 8 kg/day; in the second week: 4 kg/day; third week: 1 kg/day along with his future lick ad lib; fourth week: only his normal lick.
  6. If possible, keep the new bull away from other bulls until he gets to his cows.       In other words, the bull should work for a season before being put in with the greater bull herd.
  7. Remember that a bull cuts teeth between 2 and 2 ½ years. The bull might possibly lose weight if he has to adjust to his new environment, browse in average grazing and service cows.
  8. Ideally you should have the bull on your farm two months or more prior to the start of the breeding season to allow him to adjust to his new environment and feeding conditions.

Before the mating season

  1. It is essential to have your bulls tested for fertility three to six weeks before the onset of mating season and perform sheath washes for Trichomoniasis and Compylobacter (vibriosis). Of 10 940 bulls tested in the USA approximately 20% were unfit for use. You would normally loose at least 10% of your bulls. Identify them before the breeding season; the costs involved are much lower than the calves you will loose for not doing so. Test your ‘new’ bull too even though he might have been sold with a fertility certificate. The effect of the stress of the auction and transportation may affect his fertility in the short term.
  2. Even in systems that use multiple sire mating, it is essential to perform a semen evaluation of the bulls, as dominant bulls with poor semen can keep younger bulls with good quality semen away from the cows.
  3. Examine your bulls for general health before the mating season; make sure that they are structurally normal and that their gait is in no way awkward or abnormal.
  4. Inject bulls about two months before the breeding season with Vitamin A and minerals (Multimin + SE + Cu). Embamin and Embavit (dosed orally) are brand names of oral supplements that can also be used. This treatment may be repeated after about two months.
  5. A bull’s condition should always be 2 ½ to 3 ½ out of 5. Overfeeding causes heavy, unfit, clumsy bulls whose semen is usually sub-standard.
  6. Underfeeding may also be a problem, but normally libido decreases before semen quality is affected. If bulls are somewhat lean, start providing supplementary feeding two months before the breeding season. These may vary from a production lick to 5-10 kg concentrate per bull per day.
  7. Vaccinate bulls against crotalism (stiff-sickness) and (Compylobacter foetus) vibriosis two months prior to the breeding season.

During the mating season

  1. It is important to carefully observe your bulls, particularly young bulls.       Make sure that such bulls are adept at mating and that libido is present. Young bulls are initially inexperienced, but should be adept within a few days. Usually 10% of bulls have no or weak libido. Identify and eliminate them.
  2. In multiple sire herds put older and younger bulls in together – not bulls of equal strength. No fewer than 3-4 bulls per 100 cows. We believe in using one adult bull and two young bulls per 75 cows.       In single mating herds 30 to 40 cows should be allocated per bull for three months.
  3. Should a bull have a fever reaction as a result of red-water, gall-sickness, lympy-skin disease, three-day stiff-sickness, etc. his semen would probably be infertile and he might need two months (even longer) to recover. During the mating season closely observe the bulls to identify diseased ones immediately. Replace such a bull. Foot-rot must be treated right away by injecting long-term antibiotics. It is a painful condition and bulls will not breed until it has been cured. Make sure that your bulls remain healthy during the breeding season.       Injuries that result from fighting or other causes can eliminate a bull from the breeding season, particularly hip, leg and hoof injuries.
  4. Keep a record of the cows that were serviced. Approximately 60% of cows are fertilised in their first cycle.       If more cows return to oestrus there is a problem; it must be identified and solved as soon as possible.       You have time to do so, but you need to hurry.
  5. Mating herds should not be kept alongside one another. Bulls fight through fences and a bull with good libido will break through an ordinary fence to get to a cow on heat. With two-year old and younger bulls you might risk it with a very sturdy fence.

After the mating season

  1. Starve bulls in separate, sturdy kraals for three to four days (without food and water). Then take them to the ‘bull camp’ one by one where good grazing and clean water is freely available. Under these conditions they should forget all about cows and need to feed more than fight! The bull camp must be safe without too many stones, ditches or holes, and there must be enough space to make way for one another.
  2. The ideal is to pair bulls off (one older and one younger) and not put them all together between mating seasons and the owner can then only hope for a few injuries as possible.
  3. The bull camp can be secured by erecting double fences (3 metres apart) along the sides where other cattle are grazing. Electrical fences may be useful but require more maintenance.
  4. Because bulls frequently fight and need more ‘personal’ space, make provision for more eating space at lick troughs or when limited supplements are fed. Between 0,5 and 1 metre per bull ought to be sufficient. Truck or tractor tyres turned inside out make effective troughs for licks; they are indestructible and cannot harm the bulls in a fight.
  5. When working with the bull herd, make sure that they are not all driven into a tight group (pinned together); they usually fight under such circumstances. Bulls that have accepted one another for months will suddenly start fighting if they are moved around.
  6. Do not allow all the bulls to graze with the milking cows or another cow.  All bulls mating with the same cow might lead to cross-infection with venereal diseases.

General remarks

  1. It is advisable to have one reserve bull of every ten bulls you are using.
    Bonsmara bulls can already be used at 14 months of age as long as they weigh 420 kg, the scrotal circumference is at least 340 mm and their semen has been tested. These young bulls ought to be able to service 10 – 20 cows each in three months.
  2. Normally Bonsmara bulls can be used up to an age of ten years. Older bulls can also be used, but under special observation to see if they are still breeding well.
  3. Adult Bonsmara bulls weigh between 800 and 1000 kg; in other words, at least 1,5 to 2 LSU (Large stock units). Bear this in mind with your bull camp and fodder flow planning.
  4. Enjoy your bulls; in 90% of cases you should have no problems.