Publikationsdatenbank

Efficacy of automated activity monitoring technology at detecting cyclicity postpartum:
a meta analysis (2025)

Art

Poster

Autoren

Madureira, A. M. L.

Borchardt, S. (WE 19)

Kongress

ADSA Conference 2025

Louisville, 22. – 25.06.2025

Quelle

Journal of dairy science : JDS

Bandzählung: 108

Heftzählung: Supplement 1

Seiten: 404

ISSN: 0022-0302

Sprache

Englisch

Verweise

URL (Volltext): https://www.adsa.org/Portals/0/SiteContent/Docs/Meetings/2025ADSA/Abstracts_BOOK_2025_20250624-1249.pdf

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Abstract / Zusammenfassung

Estrous expression in early lactation is a robust predictor for fertility in lactating dairy cows. It is uncertain whether estrous expression, detected
by automated activity monitors (AAM), can be used as a proxy for resumption of cyclicity. The objective of this study was to evaluate AAM
systems to identify cyclicity of cows in early lactation. A systematic review of the literature and a metaanalytical assessment was performed.
We identified 4 studies with 7 experimental groups with information on estrous expression and ovulatory status in early lactation including 2,198
cows. MedCalc was used to analyze the data, applying a Freeman-Tukey transformation to compute the weighted summary proportion under
both fixed and random effects models. A fixed or a random effects meta-analysis was used based on the heterogeneity among the experimental
groups. Blood samples in all experiments were collected 2 times or 3 times 14 d apart for progesterone (P4) analysis. Resumption of cyclicity
was considered when P4 concentration was ≥1 ng/mL on any collection day. Cows were considered anovular when P4 concentration was <
ng/mL on all collection days. Cows were classified as true positive: P4 ≥1 ng/mL and at least 1 estrus alert; true negative: P4 <1 ng/mL and
no estrus alerts. Overall, there were 81.2% (1,785/2,198) of ovulatory cows in early lactation. Overall, there were 63.3% (1,393/2,198) of cows
detected in estrus by AAM in early lactation. The pooled proportion of true positive cows was 88.1% (95% CI: 84.9–90.9). The pooled propor-
tion of true negative cows was 35.3% (95% CI: 26.3–44.7). Substantial heterogeneity existed among the experimental groups regarding true
positive (I2 = 63.7%; P = 0.011) and true negative cows (I2 = 85.0%; P = 0.001). In summary, most cows that exhibited estrus early in lactation
also ovulated. However, the majority of cows that did not show estrus in early lactation still ovulated. Therefore, the absence of estrous activity
in early lactation is not a reliable predictor of anovulation.