Publikationsdatenbank

Analysis of daily rumination time under heat stress of lactating dairy cows (2021)

Art

Vortrag

Autoren

Müschner-Siemens, T.

Heinicke, J.

Hoffmann, G.

Ammon, C.

Amon, T. (WE 10)

Kongress

EAAP 2021 - Annual Meeting of the European Federation of Animal Science

Davos, Schweiz, 30.08. – 04.09.2021

Quelle

Book of abstracts of the 72nd Annual Meeting of the European Federation of Animal Science : Davos, Switzerland, 30th August-3rd September, 2021 — EAAP Scientific Committee: E. Strandberg, L. Pinotti, S. Messori [und 9 weitere] (Hrsg.)

Wageningen: Wageningen Academic Publishers, 2021. Book of abstracts ; No. 27 — S. 433

ISBN: 978-90-8686-366-2

Sprache

Englisch

Verweise

URL (Volltext): https://www.wageningenacademic.com/doi/book/10.3920/978-90-8686-918-3

DOI: 10.3920/978-90-8686-918-3

Kontakt

Institut für Tier- und Umwelthygiene

Robert-von-Ostertag-Str. 7-13
14169 Berlin
+49 30 838 51845
tierhygiene@vetmed.fu-berlin.de

Abstract / Zusammenfassung

In the course of the predicted climate change, the heat stress of dairy cows has become increasingly important. The temperature-humidity index (THI) is the most common approach to identify heat stress, but the index does not include animal based indicators and the stress condition cannot be determined individual for each animal. The object of the study was to determine a heat stress threshold of the average daily THI that results in changes in the daily
rumination time (RT) of lactating, high-yielding cows. The data set was composed of a high sample size of 183 cows and long-duration measurements over two years (June 2015 – May 2017), collected in a naturally ventilated barn in Groβ Kreutz, Germany. The THI was calculated in 5-min intervals in different positions inside the barn. Additionally, every cow from the herd of an average herd size of 53 cows was wearing a neck collar with a Lely Qwes HR system that provided the RT 24 h/d. The study showed that heat stress also negatively influenced RT in moderate climates.
The heat stress threshold of 52 THI was determined by broken-stick regression. Below the threshold, the RT already decreased slightly with increasing THI, but above the threshold, RT decreased more strongly from 535 min/d down to 485 min/d at 77 THI. During the experimental period, the determined threshold of 52 THI was reached from April to September for up to 720 h/month. The changes in RT in reaction to heat stress will be affected by cows’
characteristics. Therefore, we considered several cow-related factors, such as milk yield, lactation number, lactation stage and pregnancy stage to better understand cows’ individual reactions. High-yielding cows showed high RT at approximately 9 h/d during environmental conditions with THI units under 52, but they strongly reduced their RT to 8 h/d under conditions above THI 52. Multiparous, high-yielding cows in later lactation stages are potentially more strongly affected than other cows.