Making the Difference: A.I. Success is in the Details
Dr. Kim Egan, Dairy Consultant Manager, Genex
There are many factors that can affect the reproductive success of your herd. For example, a high incidence of mastitis, heat stress or an unbalanced ration can impact a herd's conception rate. When considering pregnancy rate success, it all boils down to two factors, heat detection and conception rates. Improving either, or both, will increase the pregnancy rate. Here are some basics that can be counted on to improve fertility.
Getting it Right
"Fertility Programs" is how Dr. Paul Fricke from the University of Wisconsin refers to the newer synchronization protocols. The original Ovsynch program was designed so cows would ovulate and be bred on the same day, and it works. Newer programs like Double Ovsynch and G6G/Ovsynch improve conception rates by increasing circulating progesterone. These programs require more time and good compliance but can boost first service conception into the mid-40%s.
Coupled with good conception rates, good heat detection gets cows bred accurately. Should you "cherry-pick" cows during the synchronization program? This question cannot be answered simply. Every farm is different. The answer relies heavily on record-keeping abilities and heat detection capability. The most basic fact of A.I. is cows (and heifers) only get pregnant if they get bred. Of course, breeding has to occur at the proper time. How many eligible cows are actually bred in a 21-day cycle? This is your heat detection or service rate. The 83 herds in the Genex Dairy Performance Navigator℠ program that comprise the top 10% by cow pregnancy rate average over 62% heat detection rates. These "Top 10%" herds also have less than 1% of cows with first breedings after 100 days in milk.
The common tie between conception and heat detection is proper insemination technique. Finding a cow in heat and the cow being optimally fertile doesn't necessarily result in high conception rates if insemination technique is lacking. There are numerous details that can be forgotten or incorrectly timed, so breeder refreshers can be beneficial on many farms. The most successful technicians pay attention to details, are accurate in semen placement, handle cows and semen properly, and do it al efficiently.
Why are some cows "problem cows?" Even within single herds where all cows eat the same TMR, experience the same comfort level and have the same milking prep, there are cows that excel and those that do not. if you haven't done so, take a look at their genetic parent averages or their genomic results. Traits like Daughter Pregnancy Rate (DPR) and Lifetime Net Merit (LNM) make a big difference. You can see the difference in days open across all lactations in cows with higher LNM parent averages versus those with lower averages. See the herd example in Table 1. These results are similar in every herd I have analyzed. Multiply those differences by the number of cows in your herd and the benefits of improving genetics are astounding!
Developing a Master Plan
Many farms have implemented breeding strategies to more rapidly advance genetic potential in their herds. The heifer group generally has been sired by the most genetically advanced sires compared to the rest of the herd. They also generally have the best conception rates, so they can be looked to for providing more daughters for the future herd. Graph 1 shows how the heifer group has a higher LNM sire average versus the lactating cows.
Cows with poor performance and undesirable characteristics can continue to milk, but using beef sires or selling their progeny outright will eliminate those genetics from your herd. There are numerous ways to implement a breeding strategy, customized to your herd and your needs. If you'd like more information, ask your Genex representative.
Attention to details in daily work (milking prep routines, calf feeding, ration, etc.) makes a lot of the difference in the success of farms. Fertility programs, heat detection, A.I. technique and genetic advancement make the difference in breeding program success.