<abstract xmlns="http://www.w3.org/1999/xhtml"><p>The aim of this study was to evaluate the effects of evaporative cooling at two different frequencies per day on the respiration rate (RR) of lactating dairy cows, considering cow-related factors. Twenty multiparous Israeli Holstein dairy cows housed in a naturally ventilated cowshed were divided randomly into two treatment groups. The cows of both groups were exposed to 3 or 8 cooling sessions per day (3xcool vs. 8xcool, respectively). The RR was observed hourly, with a maximum of 12 measurements per day. Body posture (standing vs. lying) was simultaneously documented. Milk yield was recorded daily. Coat color was determined from a digital photograph. The RR of standing and lying cows was lower in the 8xcool group (60.2 and 51.6 breaths per min (bpm), respectively) than in the 3xcool group (73.1 and 65.6 bpm, respectively). For each increment of five kilograms of milk produced, RR increased by one bpm, and the RR of cows in early days in milk (DIM) was 12.3 bpm higher than that of cows in late DIM. In conclusion, eight cooling sessions per day instead of three lead to a RR abatement in heat-stressed cows under hot conditions, and cow-related factors directly impact the RR during heat stress assessment.</p></abstract>

The aim of this study was to evaluate the effects of evaporative cooling at two different frequencies per day on the respiration rate (RR) of lactating dairy cows, considering cow-related factors. Twenty multiparous Israeli Holstein dairy cows housed in a naturally ventilated cowshed were divided randomly into two treatment groups. The cows of both groups were exposed to 3 or 8 cooling sessions per day (3xcool vs. 8xcool, respectively). The RR was observed hourly, with a maximum of 12 measurements per day. Body posture (standing vs. lying) was simultaneously documented. Milk yield was recorded daily. Coat color was determined from a digital photograph. The RR of standing and lying cows was lower in the 8xcool group (60.2 and 51.6 breaths per min (bpm), respectively) than in the 3xcool group (73.1 and 65.6 bpm, respectively). For each increment of five kilograms of milk produced, RR increased by one bpm, and the RR of cows in early days in milk (DIM) was 12.3 bpm higher than that of cows in late DIM. In conclusion, eight cooling sessions per day instead of three lead to a RR abatement in heat-stressed cows under hot conditions, and cow-related factors directly impact the RR during heat stress assessment.

Effect of Two Cooling Frequencies on Respiration Rate in Lactating Dairy Cows Under Hot and Humid Climate Conditions

Department of Engineering for Livestock Management

Institute of Animal Hygiene and Environmental Health

Annals of Animal Science

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The aim of this study was to evaluate the effects of evaporative cooling at two different frequencies per day on the respiration rate (RR) of lactating dairy...

Effect of Two Cooling Frequencies on Respiration Rate in Lactating Dairy Cows Under Hot and Humid Climate Conditions

Published Online: Jul 30, 2019

Page range: 821 - 834

Received: Nov 26, 2018

Accepted: Mar 26, 2019

DOI: https://doi.org/10.2478/aoas-2019-0026

Keywords
heat stress, evaporative cooling, cow-related factors, precision livestock farming (PLF), animal welfare

© 2019 Severino Pinto et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Effect of Two Cooling Frequencies on Respiration Rate in Lactating Dairy Cows Under Hot and Humid Climate Conditions

Published Online: Jul 30, 2019

Page range: 821 - 834

Received: Nov 26, 2018

Accepted: Mar 26, 2019

DOI: https://doi.org/10.2478/aoas-2019-0026

Keywordsheat stress, evaporative cooling, cow-related factors, precision livestock farming (PLF), animal welfare

© 2019 Severino Pinto et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
heat stress, evaporative cooling, cow-related factors, precision livestock farming (PLF), animal welfare