The foundation for reproduction is a sound year round nutrition program that includes animals being in a positive energy balance (more energy coming in than being expended) before the breeding season and during early embryonic development. Subclinical trace mineral deficiencies can result in reduced conception rates but adding more of the same or a different source of a trace mineral above requirement may or may not increase level of reproduction. Partner with your veterinarian to develop a sound animal health and biosecurity program to minimize drags to reproductive response. Presence of even one animal persistently infected with BVD will re- duce herd fertility.
A herd that typically achieves 85% or greater pregnancy rate in a 60 day breeding season makes a good candidate for an artificial insemination and estrous synchronization program. The following checklist should draw attention to the details that make these programs more successful.
• Responses will be highest in cows that are 45 days from calving or greater at the time of AI and in a body condition score of 5 or greater.
• Use a synchronization system with a CIDR or MGA if you suspect some females are not cy- cling.
• Moving a later calving co w to an earlier calving date generates roughly 40 lbs more calf per cycle advanced. Consider use of more economical semen on these females that are in good condition and at least 30 days since calving at AI.
• Select from the short list of recommended synchronization protocols published in major sire catalogs.
• Follow the protocol as outlined. Pay particular attention to the recommended intervals between the last injection of prostaglandin and timed AI.
• Use the Estrus Synchronization Planner or www.estrussynch.com for mobile devices to plan and schedule your synchronization pro- gram. Double check the necessary help is avail- able on the scheduled dates.
• Only synchronize as many animals as you can inseminate in your facilities in a 3 to 4 hour time window.
• For timed-AI, don’t overestimate your ability to inseminate a large number of females. Have a back-up plan or more help available.
• Double check you have the necessary doses of synchronization products on hand. Give the correct product on the correct day and at the proper dosage via the correct route. These items are easy to confuse when you only use them once per year.
• Make sure each animal receives the treatment, accuracy is more important than speed. Use 1.5" 18 gauge needles to give intramuscular injections. Follow BQA guidelines.
• Before the season starts, check the accuracy of an automatic thaw unit and monitor while in use. Clean thaw unit on a regular basis.
• Use thawing instructions from semen provider; generally in the range of 90-98° F for 30 to 45 seconds. Use a watch or timer, do not guess.
• Clean and inventory supplies in AI kit; ensure an adequate supply of gloves, sheaths, lube and paper towels.
• Handling facilities should be in good working condition to minimize stress on animals and people.
• Replace missing or unreadable ear tags.
• Use a Certified Semen Services (CSS) provider. A check of semen quality prior to freezing is not part of the routine processing done in smaller collection facilities.
• Keep accurate inventory records of the semen tank(s).
• Canisters should not be raised above the frost line in the neck of the tank for more than 5-8 seconds. Thermal injury is permanent. In- creased handling increases the risk of damage.
• Thaw no more semen than can be used in 10 minutes or less. Prevent straw to straw contact when thawing.
• If breeding on heat keep de tailed records at each check. Inseminate 4 to 12 hours after first ob- served standing heat.
• Keep natural service sires out of breeding pasture until 10-14 days after AI if you want to identify AI-sired calves without DNA parentage testing.
• Avoid stressors such as those caused by transportation, nutritional changes or ambient temperature/humidity strain during early embryonic development. Most sensitive from day 5 to 18 (embryo arrival in uterus through maternal recognition of pregnancy) and still sensitive until attachment is complete at day 42.
For more information see the publication Tips for a Successful Synchronization Program here.