BUYING A BULL can be costly and risky, but semen quality assessments could improve reproductive efficiency in suckler herds and provide buyers at bull sales with even more assurance.
Research suggests about 20% of bulls are infertile or subfertile, said SAC’s George Caldow at a press briefing Edinburgh to launch a new addition to SAC’s bull health declarations. Semen tested bulls will be given a green star to say they have been successfully tested.
United Auction’s marketing director David Leggatt expects this will increase the level of quality assurance of beef bulls at sales. “Following the launch of bull declarations in 2003, there has been a 30% uptake at Perth Bull Sales, with a greater uptake predicted for the February sales.
“The addition of semen quality assurance to the declaration will provide an extra tool for purchasers to match their requirements, as well as reduce post sale disputes. This initiative will be particularly welcomed by commercial producers.”
In any breeding operation, Mr Caldow believed a pre-breeding examination for stud bulls would help improve efficiency. “Clinical examination and advice regarding locomotion and the reproductive tract should be considered.”
Mr Caldow added that a bull with maximum fertility is capable of mating 50 or more cows in a two-month breeding season and achieving 96% in calf. “The top 20% of herds are reaching that. Further to examination, bulls that are, or are likely to be, subfertile should be removed to match breeding capacity to group size,” he said.
Previous methods of breeding evaluation have involved collection of semen with an artificial vagina, but this has had its difficulties, he explained. “Cows must be in oestrous and restrained, bulls must be halter led and the process can be expensive and potentially dangerous, particularly with issues surrounding on farm labour.”
Collecting semen through electro-ejaculation means bulls can be restrained in crushes rather than halter led. However, Mr Caldow pointed out that this form of assessment does not allow for assessing either libido or the ability to serve.
Now accepted by Royal College of Vet Surgeons and RSPCA, two training courses have already been held with 40 vets now trained. Kelso vet Robert Anderson who carries out the training said 30 practices now have the capacity to deliver the service.
Mr Anderson added that average cost for electro-ejaculation assessment would be about 50 a bull, with initial set-up costs for equipment averaging 2000 for most vet practices.
However, Mr Caldow pointed out those bulls without the assurance star on the declaration does not mean they are infertile. “They may just not have been tested.”