The Impact of Heat Stress on Conception Rate in Dairy Cattle: Meta-Analysis Study

Özcan Ö., Dikmen S.

International One Health congress, Tekirdağ, Türkiye, 11 - 12 Aralık 2025, ss.100-104, (Tam Metin Bildiri)

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Basıldığı Şehir: Tekirdağ
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.100-104
  • Bursa Uludağ Üniversitesi Adresli: Evet

Özet

Abstract

The aim of this study is to systematically evaluate and quantify the effect of heat stress on conception rate in dairy cattle through a comprehensive meta-analysis of peer-reviewed studies, thereby informing strategies to mitigate climate-related reproductive challenges in livestock production. Peer-reviewed articles published between 2010 and 2023 were retrieved from Web of Science, ScienceDirect, Scopus, and NIH (National Library of Medicine) databases. Following the literature search, a total of 2046 records were initially identified. After removing 605 duplicates, 1441 unique publications were included for further evaluation. Inclusion criteria were defined according to the PRISMA and PICOS framework, and studies reporting conception rate data under heat stress conditions in dairy cows were selected for analysis. Ultimately, meta-analyses were completed from 20 academic studies.

The meta-analysis was performed using MetaXL version 5.3, applying the Inverse Variance Heterogeneity (IVhet) model. This model was chosen for its robustness in handling datasets with high heterogeneity. The pooled effect size (Cohen’s d = –26.074; 95% CI: –47.781 to –4.367) indicated a statistically significant and strongly negative impact of heat stress on conception rate. Heterogeneity among studies was found to be extremely high (I² = 99.93%; Q = 49,944.507; p < 0.001), and further explored through meta-regression analysis.

Publication bias was assessed using the Doi plot and Egger’s linear regression test, with results supporting the reliability of the findings. Overall, this meta-analysis provides a comprehensive synthesis of the adverse effects of heat stress on reproductive performance in dairy cattle and offers valuable insights for managing climate-related production risks in livestock systems.

Keywords: Heat Stress, Dairy Cattle, Fertility, Conception Rate ,Meta-Analysis