Achieving Success With Systematic Breeding Programs
Posted: October 7, 2004
There are a variety of programs available to dairy producers for synchronizing estrus and ovulation. Some systems require heat detection during specific days following hormone injections while the Targeted Breeding and Presynch - Ovsynch programs are based upon a combination of heat detection / timed breeding or solely timed insemination. I have seen several systematic breeding programs implemented on dairy farms. Most are well designed but some are not effective for various reasons. It is worth reviewing once again the requirements for success that are common to all systems.
- Gonadotropin releasing hormone (GnRH), prostaglandin (PG) and progesterone (P) are the major hormones used in synchronization programs. However, none of these are very effective in truly anestrous cows. Lactating cows experiencing severe negative energy balance are not candidates for such systems. Cows must be cycling in order that hormonal protocols properly synchronize follicular development, regress the corpus luteum, and induce ovulation. Priority should be given to minimizing negative energy balance and loss of body condition during early lactation. Body condition should be monitored on a routine basis. Research from Florida clearly shows that the percentage of cows conceiving to timed insemination during an Ovsynch program was reduced for cows in lower body condition (<2.5 BCS) than herdmates with BCS > 2.5.
- Voluntary waiting period (VWP) should be established and used as a critical control point for the entire reproductive management program. Furthermore, research indicates that pregnancy rate per service was higher for the Presynch - Ovsynch program when the timed insemination occurred shortly after day 75 postpartum than before day 75.
- A calendar or electronic record system should be used so that injections, heat detection and inseminations are performed on days specified by the protocol and; appropriate personnel should be available to perform these tasks correctly and in a timely manner. Standard operating procedures (SOP) should be posted and understood by everyone involved with implementing the program.
- Personnel must adhere to the sequence and timing of injections as prescribed by the protocol for the specific system being used. These systems were developed following extensive field research. Too often only certain cows within the herd are assigned to a synchronization program. Using this approach negates the primary advantage of improving overall herd heat detection rate (submission rate for AI) which is the primary advantage of the Presynch-Ovsynch timed AI program.
- Use the correct weapon on the right target - when administering 2-cc or less use smaller syringes. GnRH and PG should be injected into the muscle so use the appropriate size needle for the area where the muscle is located. Long needles may pass through the muscle. Review these procedures with your veterinarian. Keep the hormones refrigerated.
- Research clearly shows the benefit of using prostaglandin injections prior to the VWP as a set-up shot for the Targeted Breeding or the Ovsynch programs. The purpose of these injections is to induce cattle into a stage of the estrous cycle, between days 5 and 12, when they are likely to respond to the initial synchronization injection.
- Depending upon the system being used, heat detection must be intensified on the days when the cows are likely to exhibit heat. This means more frequent heat detection and use of heat detection aids.
- Even though the Presynch-Ovsynch programs are designed for timed insemination during a specific interval following the last injection, this does not imply that heat detection is no longer necessary. To maximize the effectiveness of any system, the post breeding heat detection rate (detection of return heats) must be high.
- Pregnancy examinations must be scheduled routinely so that open cows are identified and scheduled back into a synchronization program.
Successful reproductive management depends on teamwork. Herd managers should consult with the veterinarian and AI personnel so that everyone is on the same page and working toward the same objective. There isn't any hormonal protocol that will overcome anestrus, poor uterine health, inadequate vaccination, sloppy insemination technique and environmentally stressed cows.
Michael O'Connor, Dairy and Animal Science Extension