Publikationsdatenbank

Timing of artificial insemination using fresh or frozen semen after automated activity monitoring of estrus in lactating dairy cows (2019)

Art

Vortrag

Autoren

Tippenhauer, C. M. (WE 19)

Plenio, J. L. (WE 16)

Madureira, A. M.

Cerri, R. L.

Heuwieser, W. (WE 19)

Borchardt, S. (WE 19)

Kongress

17th International Conference on Production Diseases in Farm Animals

Bern, 27. – 29.06.2019

Quelle

17th International Conference on Production Diseases in Farm Animals - Proceedings — Rupert M. Bruckmaier, Josef J. Gross (Hrsg.)

1 Auflage

Bern: Veterinary Physiology, Vetsuisse Faculty University of Bern Bremgartenstrasse 109a CH-3012 Bern, Switzerland, 2019 — S. 180

ISBN: 978-3-906813-93-6

Verweise

URL (Volltext): https://boris.unibe.ch/131406/

DOI: 10.7892/boris.131406

Kontakt

Tierklinik für Fortpflanzung

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14163 Berlin
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fortpflanzungsklinik@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Introduction
Timing of artificial insemination (AI) relative to ovulation is of particular importance for pregnancy outcomes. It represents a compromise between fertilization rate and embryo quality. The major challenge is to identify the time of ovulation. Typically, this was based on visual observation of cows eligible to be bred. Poor estrus detection, however, is a major contributor to impaired reproductive performance in high yielding dairy cows in confinement systems. To overcome this challenge automated activity monitoring systems (AAM) have been implemented to improve estrus detection. However, there is only little research on the optimal timing of insemination relative to changes in activity using commercial automatic monitoring systems. The objective of this observational experiment was to determine the association between the interval from reaching an activity threshold (AT) using an AAM and the time of artificial insemination on P/AI for lactating Holstein cows inseminated with either fresh or frozen semen.

Materials and Methods
Lactating Holstein cows (n = 3,420) from 7 commercial dairy farms were inseminated based on visual heat detection and/or based on the alert of an accelerometer system (Heatime; SCR Engineers Ltd., Netanya, Israel). Pregnancy diagnosis was performed by transrectal palpation 35 ± 7 d after AI. Data were analyzed using the GENLINMIXED procedure in SPSS. Onset of estrus was defined as the time when the AT (index value ≥ 35) was reached. Estrus intensity was categorized based on peak activity change into low (index value 35 to 80), medium (81 to 99), and high intensity estrus (100).

Results
The mean (± standard deviation) interval from onset of estrus to AI was 15.0 ± 8.9 hours. Pregnancy per AI was affected by parity (P = 0.001), season (P = 0.001), estrus intensity (P = 0.001), and the interval from reaching AT to AI (P = 0.001). Type of semen (P = 0.231) and the interaction of type of semen with interval from reaching AT to AI (P = 0.981) had no effect on P/AI. Primiparous cows (31.1 %) had higher P/AI compared with multiparous cows (24.9 %). Cows inseminated in the hot season (July until September; 23.7 %) had lower P/AI compared with the cold season (October until January; 32.4 %). Cows with a high intensity estrus (32.7 %) were more fertile compared with medium (29.1 %) or low intensity estrus (22.4 %). There was a quadratic effect of the interval from reaching AT and AI on probabilities of pregnancy. Pregnancy per AI at 35 d after AI was highest for cows inseminated between 13 to 24 hours after onset of estrus (-24 - 0 hours = 22.7 %, 1 - 6 hours = 23.0 %, 7 - 12 hours = 30.0 %, 13 - 18 hours = 34.0 %, 19 - 24 hours = 32.0 %, 25 - 48 hours = 26.8 %).

Conclusions
In conclusion, inseminating cows 13 to 24 hours after passing the AT yielded the highest P/AI irrespective of type of