Usage Suggestions for electroejaculators
- Immobilize the bull Use a headgate and squeeze chute, or similar solid enclosure, to limit the side-to-side and forward and backward motion of the bull. Bulls with room to move are more likely to fall, making collections more difficult.
- Footing is critical Providing secure footing is perhaps the most important aspect of preparing a bull for collection. Bulls that are slipping and sliding are difficult to collect. Some veterinarians spread a bucket of sand over the enclosure’s floor to increase a bull’s footing, and others have bulls stand in ankle-deep sand to insure stable footing.
- Pre-stimulate the bull Manually pre-stimulating the bull by gently massaging the prostate and ampullae for 10-15 seconds prior to inserting the probe can relax the animal, and shorten the collection time.
- Try automatic mode first Veterinarians have found that up to 90% of bulls can be quickly collected using an electroejaculator’s automatic mode if available. Manual mode is most useful with older bulls that are more difficult to stimulate.
- Charging the battery Check the suggested charging information for the electroejaculator you are using.
Beef bulls by the numbers
The National Animal Health Monitoring Service (NAHMS) recently released Beef 2007–2008 study indicates that the most common breeding method used by cow-calf producers is “natural service” by a bull only. For breeding, most heifers (79.2%) and cows (94.2%) were only exposed to a bull (as opposed to AI). Cow-calf producers expected mature bulls to service 25 females and yearling bulls to service 17 females. Most reproductive specialists advocate that a mature bull can service 25 to 35 cows; however it has been shown that highly fertile bulls can service up to 50 cows.
Breeding soundness exams
The percentage of operations that tested the semen of at least some bulls in preparation for the last breeding season ranged from 18.1% of operations with 1 to 49 beef cows to 61.1% of operations with 200 or more beef cows. A lower percentage of operations with 1 to 49 cows performed scrotal measurements in preparation for the last breeding season than did larger operations. Of the 30.7% of operations that purchased, leased, or borrowed bulls for the last breeding season, 71.3% semen tested at least some of these bulls.
Only 9.8% of operations cultured bulls for Tritrichomonas fetus, and just 18.5% of bulls were cultured for T. fetus in preparation for the last breeding season; 35.1% of operations that purchased, leased, or borrowed bulls in preparation for the last breeding season cultured bulls. Additionally, 53.3% of operations that purchased, leased, or borrowed a bull, added bulls that were more than 18 months of age or no longer considered virgin, but only 34.4% of those operations cultured all these bulls for T. fetus.