At 95 percent accuracy of estrus detection and 95 percent compliance, the profits for estrus detection, Presynch-Ovsynch, and Presynch-Ovsynch-estrus detection were $403, $371, and $443, respectively.
At 85 percent accuracy of estrus detection and 85 percent compliance, the profits were $337, $277, and $378, respectively.
The difference from 95 percent to 85 percent compliance and/or accuracy for the three protocols was $56, $94, and $65, respectively.
A combination of timed-AI with estrus detection, with good compliance (95 percent) and accuracy (95 percent), will give you the best results. The estrus detection protocol is better than Presynch-Ovsynch with similar accuracy and compliance, but Presynch-Ovsynch with good compliance is better than estrus detection with poor accuracy.
Of all programs, Presynch-Ovsynch was the most sensitive to changes in compliance and/or accuracy of estrus detection.
At 95 percent compliance and 95 percent accuracy of estrus detection, the time to reach the new level of pregnancy for the three protocols was 3.4 months, 6.7 months, and 4.1 months, respectively.
The time length to reach the new level of milk yield for the protocols took an additional 5.4 months, 8.8 months, and 7.5 months from pregnancy, respectively. According to the model, the new level of pregnancy should be evident around three to six months post-change with an additional five to eight months for milk yield.
Assuming that herd size remains constant, the timing to event (new level of pregnancy and milk yield) provides a timeline to monitor the expected true benefits when an improvement in reproductive management is made (compliance or accuracy of estrus detection) at the farm level.
The combination of Presynch-Ovsynch with estrus detection resulted in the greatest profit, followed by estrus detection and Presynch-Ovsynch only. The economic benefit of timed-AI protocols, such as Presynch-Ovsynch, depends on compliance with each injection. Dairy farmers should consider their accuracy of estrus detection and compliance to reproductive protocols before implementing a reproductive program.
The information provided in this article was generated using an individual cow-based model to aid in decision making about reproductive management of dairy cows. The model was developed in collaboration with Drs. P. Federico (Capital University, Columbus, Ohio), A. De Vries (Department of Animal Sciences, University of Florida, Gainesville, FL), G.M. Schuenemann (Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio), and K.N. Galvão (Department of Large Animal Clinical Sciences, University of Florida, Gainesville, Fla).
- P. Federico, A. De Vries, G.M. Schuenemann, and K.N. Galvão. 2011. An individual cow-based model to aid in decision making about reproductive management of dairy cows. J. Dairy Sci. 94:350.
- G.M. Schuenemann, P. Federico, A. De Vries, and K.N. Galvão. 2011. Timing to reach the new level of pregnancy and milk yield after an improvement in reproductive management in dairy herds. J. Dairy Sci. 94:257.
- K.N. Galvao, P. Federico, A. De Vries, and G.M. Schuenemann. 2011. Economic comparison of reproductive programs for dairy herds using estrus detection (ED), Ovsynch, or a combination of both. J. Dairy Sci. 94:257.
Source: Buckeye Dairy News, July issue