Achieving excellent reproductive performance is a critical goal for dairies because reproductive efficiency drives profitability by maintaining cows in the herd at optimal production levels.
Concentrating on seven key factors can lead to reproductive success, Paul Fricke of the University of Wisconsin-Madison said at an educational seminar at World Dairy Expo Friday.
1. Inseminate cows at the correct time in relation to estrus or ovulation.
Timing of AI in relationship to detecting estrous behavior or synchronized ovulations can affect subsequent fertility. For farms that AI some or all of their cows to a detected estrus, a single mid-morning AI for all cows and heifers detected in estrus the night before or the same morning should result in near-maximal conception rates. "That’s an effective alternative to using the a.m./p.m. rule to manage AI breeding programs," Fricke said. For farms using TAI, Fricke recommends using Ovsynch 56
for an optimized protocol based on empirical data as well as the physiology of AI timing in relation to ovulation.
2. Improve AI efficiency. This refers to factors affecting pregnancy rates due to AI technique. "Research has consistently shown that people responsible for conducting AI on a farm can have a profound effect on fertility," said Fricke. In research trials, fertility of cows inseminated by professional AI technicians almost always exceeds that of herd employees. These studies strongly support use of professional AI technicians when AI technique is a suspected cause of low conception risk on a farm.
3. Inseminate cows quickly after the end of the voluntary waiting period. It’s a fundamental principle of reproductive biology that inseminating a cow is the first step toward establishing a pregnancy. Fricke said first postpartum AI service represents a unique opportunity for reproductive management of lactating dairy cows because all cows in the herd have a known pregnancy status (non-pregnant) at this time, which allows for the use of hormonal synchronization systems that use PGF2a without the risk of aborting a previously established pregnancy.
4. Maintain high compliance to synchronized breeding protocols. "To achieve success with TAI protocols, each farm has to develop a system to administer the correct injections to the correct group of cows on the correct days, then subsequently AI the correct group of cows," Fricke said. Inability to comply with TAI protocols is a widespread cause of poor reproductive performance and needs to be addressed when TAI protocols are used to manage reproduction.
5. Identify non-pregnant cows early after an insemination (but not too early). Although it has long been accepted that pregnancy status should be determined in dairy cows as soon as possible after AI, the accuracy of pregnancy diagnosis outcomes determined early after AI are confounded by subsequent pregnancy loss. Fricke said rectal palpation should not be done before about 35 days after AI. Ultrasound should not be done before about 28 to 30 days after AI.
6. Aggressively re-inseminate non-pregnant cows. Although relying on synchronization of ovulation and TAI for improving service rate to first AI service reduces the impact of poor estrous detection, the improved AI submission rate to first TAI often is followed by a time lag exceeding 60 days before cows failing to conceive are detected and re-inseminated. Although new strategies are under development, Fricke advises administering GnRH to all cows 32 days after a previous TAI and conducting non-pregnancy diagnosis at 39 days so that non-pregnant cows can continue the protocol.
7. Adopt and adapt to new technologies. Many technologies are now becoming available to help manage reproduction in large herds. "Some of these new technologies will be incorporated in dairy management systems, whereas others will not," Fricke said. "Each dairy manager must evaluate the potential that these new technologies have to offer."
Micro Dairy Logic sponsored the seminar.