By sarvika
4. POST-JOINING:
a. Annual breeding soundness evaluation is a non-negotiable procedure. b. Good management of bulls is a year-round procedure.
i. Keep bulls in working body condition - they should be in body condition score 3/5 at the start of mating, which will involve removing weight following the joining period.
ii. Manage bulls in groups of joining teams to establish stable social hierarchies and minimise bull fighting.
Bulls need to be removed from the cows at the same time, to help create their bull mobs. This will limit the number of potential injuries by reducing the number of bull interactions.
Bull paddock management is very important to minimise injury between joinings. The bulls need enough room to reduce fighting, restricted feed and water will increase interaction. Paddocks will require co-grazing with sheep, or crash-grazing by other mobs to manage feed quality and quantity on offer for the bulls.
✓ The target between joining is to restrict weight gain in older bulls to prevent breakdowns. Ideally young bulls have access to a higher level of nutrition as they continue to grow.
✓ Early pregnancy testing is essential for good female management and detection of surprises. The earlier the pregnancy testing is undertaken, the more likely the cause of the problem will be identified. This will not only give you early notice of the problem but also help in formulating a plan to help reduce the chance of the problem occurring again in the future.
PENILE INFECTIONS IN BULLS - "Balanoposthitis":
Penile infections are a common disease in young bulls during their first joining season in any new herd. Mitigating the risk of this disease as outlined above is essential to reduce the number of breakdowns and optimise bull cost per calf.
These infections are caused by a range of bacterial, viral, and other organisms ("pathogens"). The genital form of infectious bovine rhinotracheitis (IBR; herpes virus) is commonly implicated. The issue is that any given property has its own population of reproductive tract pathogens and if the new bulls make their first contact with these pathogens at the time of high workload (such as joining) they are at a high risk of developing a penile injury.
These injuries typically involve a reddened inflamed penis, developing to ulceration and pustules. Some bulls will stop serving due to pain (will continue to mount, but not serve), but other high libido bulls will continue to serve and create significant inflammation commonly leading to preputial tears, abscesses and prolapses. These are often perceived to be a “broken penis", which they are not and IF treated promptly may regain normal function!
Treatment involves prompt removal of the affected bull from the joining mob, sexual rest (typically for the remainder of the joining) and treatment with antibiotics and anti-inflammatories. Preputial prolapses require surgical replacement.
If undetected these injuries commonly cause a significant decrease in pregnancy rate and commonly result in permanent infertility in the bull. Observation and intervention are essential!
Prevention of this condition is best achieved as outlined above, by deliberate pre-exposure of new bulls to a small number of females (low workload) well before the joining so that they are exposed and can develop immunity to the herds' pathogens prior to the high workload of the joining period.
Positive fertility outcomes are a significant driver of profitability in beef breeding enterprises, but this requires informed and active management!
Dr. Shane Thomson BVetBio. BVSc. MAnSc. for HOLBROOK VETERINARY CENTRE.
HVC production & breeding www.holbrookvetcentre.com.au