Getting bulls ready for joining
Many producers are getting ready to join bulls for a spring calving period. An important goal in any beef breeding herd is a short calving period with a high weaning percentage from all groups of cows. Therefore bulls must be willing and able to serve a high percentage of cows on heat and free of any abnormalities of the reproductive tract, feet and legs.
Ideally bulls are examined during the weeks leading up to joining. There are many things that can be checked that influence the success of a bull’s joining period, including scrotal circumference, sperm morphology and motility, the reproductive tract, soundness and health of the bull, mating ability and libido, age and condition, and social interactions between bulls.
Producers can ensure bulls are in good condition and should aim to have them at a body condition score of three in the time leading up to and at joining. Bulls in poor body condition can have lower sperm quality, while over conditioning can also lead to a decline in sperm quality and put unnecessary stress on a bull’s musculoskeletal system. When running multiple bulls use bulls of a similar age in a single mob of cows and run the bulls together in the eight weeks prior to joining to encourage bulls to spend their time serving cows as opposed to fighting. Check the soundness of bulls, making sure they move well and are not lame. Measure scrotal circumference and palpate testicles to check for abnormal swelling, softness, lumps and bumps. It is important to observe bulls during joining to make sure they are serving well and have not broken down.
Private veterinarians can add value to any bull examination conducted by a producer. They can perform a thorough physical examination including all the parts of the reproductive tract. They can also evaluate semen to determine its quality. A serving ability test is also often done to gather information on the ability of a bull to mate a cow and his desire to do so. When purchasing bulls always seek a report from a private veterinarian on bull breeding soundness. This report does not guarantee fertility, but it does give an indication of whether or not a bull is likely to be fertile at the time the exam was conducted.
The pre-joining exam is a great time to ensure routine preventative health measures have been put in place. Bulls should be vaccinated annually 4-6 weeks prior to joining against vibriosis and pestivirus, and they should also receive their annual 5-in-1 or 7-in-1 booster at this time. Finally, bulls should receive an annual effective internal parasite drench and be treated for any external parasites.
If a low percentage of heifers and/or cows are found to be pregnant at the time of pregnancy diagnosis your Local Land Services district veterinarian can assist you in investigating the cause of this outcome. Your district veterinarian can also advise you on herd management to help maximize the reproductive performance of your stock. Contact your nearest Local Land Services office for further information.