Publikationsdatenbank

Effect of transition cow health and estrous expression detected by an automated activity monitoring system within 60 days in milk on reproductive performance of lactating Holstein cows (2025)

Art

Vortrag

Autoren

Borchardt, Stefan (WE 18)

Madureira, Augusto

Kongress

Vlaamse Buiatric Congress

Dilbeek, 23. – 24.10.2025

Quelle

Sprache

Englisch

Kontakt

Nutztierklinik

Königsweg 65
14163 Berlin
+49 30 838 62261
klauentierklinik@vetmed.fu-berlin.de

Abstract / Zusammenfassung

The objective of this observational study was to evaluate the association of transition cow health and estrous expression, detected by an automated activity monitoring system (AAM), with reproductive performance in lactating Holstein cows.

A total of 13,984 lactating Holstein cows (5,143 parity 1; 4,029 parity 2; 4,812 parity 3 or greater) from a commercial dairy farm in Slovakia calving from January 2020 until December 2024 were enrolled in this study. Activity data were recorded from d 7 until d 60 postpartum using a neck mounted AAM system (Smarttag Neck, Nedap Livestock Management). Within this observational period, cows were classified into: (1) no estrus event (Estrus0) or (2) at least 1 estrus event (Estrus1). Transition cow health was assessed by farm personnel within the first 30 d in milk (DIM) using standard operating procedures. Calving related events (i.e., dystocia, stillbirth, twins) and health disorders (i.e., retained fetal membranes, metritis, mastitis, displaced abomasum, milk fever, hyperketonemia [blood β-hydroxybutyrate ≥1.2 mmol/L]) were recorded and considered as a risk factor for anestrus. Based on the number of calving related events or health disorders cows were grouped into three categories: no risk factor (NoRF), 1 risk factor (RF1), or more than one risk factor (RF2). Reproductive outcomes of interest were pregnancy per AI and pregnancy loss at first service, and time to pregnancy. Generalized linear mixed models were used to analyze continuous and categorical data. Cox proportional hazard models were used for time to event data. Separate models were used for each parity group.

The overall prevalence of anestrus was 29.7%. The prevalence of anestrus increased with parity (L1 22.6%; L2 27.8%; L3+ 36.1%). Within each parity the prevalence of anestrus increased with the number of risk factors (L1: NoRF 20.4%; RF1 26.3%; RF2 38.1%; L2: NoRF 24.6%; RF1 29.0%; RF2 41.7%; L3+: NoRF 30.7%; RF1 39.2%; RF2 45.3%). For primiparous cows (P = 0.008), pregnancy per AI at first service was 55.0 ± 1.5%, and 59.5 ± 0.8% for cows in Estrus0 and Estrus1, respectively. For secundiparous cows (P = 0.001), pregnancy per AI at first service was 37.4 ± 1.5%, and 45.0 ± 1.0% for cows in Estrus0 and Estrus1, respectively. For cows in parity 3 or greater (P = 0.001), pregnancy per AI at first service was 34.6 ± 1.2%, and 43.2 ± 1.0% for cows in Estrus0 and Estrus1, respectively. For primiparous cows (P = 0.001), pregnancy loss at first service was 7.6 ± 1.0%, and 3.5 ± 0.4% for cows in Estrus0 and Estrus1, respectively. For secundiparous cows (P = 0.344), pregnancy per AI at first service was 7.2 ± 1.3%, and 5.9 ± 0.6% for cows in Estrus0 and Estrus1, respectively. For cows in parity 3 or greater (P = 0.001), pregnancy per AI at first service was 9.8 ± 1.2%, and 7.4 ± 1.0% for cows in Estrus0 and Estrus1, respectively. Compared with Estrus1 cows, cows in Estrus0 had reduced hazard of becoming pregnant within 200d in parity 1 (HR = 0.85; 95% CI 0.79 – 0.91; P = 0.001), 2 (HR = 0.77; 95% CI 0.71 – 0.83; P = 0.001), 3 or greater (HR = 0.73; 95% CI 0.67 – 0.78; P = 0.001).

In conclusion, cows with transition cow disorders had a greater chance for anestrus compared with healthy cows. Irrespective of parity, cows in Estrus0 had reduced P/AI at first AI and reduced hazard of becoming pregnant within 200d compared with cows that displayed estrous activity from d 7 until d 60. Estrous expression was associated with pregnancy loss at first service only in primiparous cows.