Modelling of heat stress in a robotic dairy farm. Part 1: thermal comfort indices as the indicators of production loss

Ji, Boyu and Banhazi, Thomas and Ghahramani, Afshin and Bowtell, Les and Wang, Chaoyuan and Li, Baoming (2019) Modelling of heat stress in a robotic dairy farm. Part 1: thermal comfort indices as the indicators of production loss. Biosystems Engineering. ISSN 1537-5110

Abstract

Thermal comfort indices (TCIs) have been developed to assess heat stress and model the relationship between thermal parameters (e.g. dry-bulb temperature) and animal responses (e.g. daily milk yield, DMY). The published models typically include temperature humidity index (THI), black globe humidity index, environmental stress index, equivalent temperature index, heat load index, respiration rate index and comprehensive climate index. This study was conducted to compare the performance of these published TCIs using data collected from a robotic farm situated in a subtropical climate region. The comparison also included models formulated between basic thermal parameters and animal responses (DMY and milk temperature (MT)). The statistical analyses found dry-bulb temperature can provide a similar level of performance to other TCIs in assessing heat stress. The spatial variability between on-farm measurements and the local weather station can be neglected when modelling with TCIs and MT. For cows with an average DMY of 31 kg cow−1 d−1, the threshold for significant decline of DMY was reported as THI >64 (P < 0.05). The daily minimum TCIs were found to be highly correlated with production loss, indicating that sufficient night-time cooling was important for preventing production losses. The potential of implementing a simplified assessment of heat stress using an on-line dataset was also demonstrated by this study.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Published online: 7 December 2019. Permanent restricted access to ArticleFirst version, in accordance with the copyright policy of the publisher.
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Sustainable Agricultural Systems (1 Aug 2018 -)
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Sustainable Agricultural Systems (1 Aug 2018 -)
Date Deposited: 22 Jan 2020 00:35
Last Modified: 30 Jan 2020 01:36
Uncontrolled Keywords: robotic dairy farming, thermal comfort index, heat stress,modelling
Fields of Research : 07 Agricultural and Veterinary Sciences > 0702 Animal Production > 070299 Animal Production not elsewhere classified
07 Agricultural and Veterinary Sciences > 0701 Agriculture, Land and Farm Management > 070103 Agricultural Production Systems Simulation
07 Agricultural and Veterinary Sciences > 0701 Agriculture, Land and Farm Management > 070105 Agricultural Systems Analysis and Modelling
Socio-Economic Objective: B Economic Development > 83 Animal Production and Animal Primary Products > 8305 Primary Animal Products > 830599 Primary Animal Products not elsewhere classified
Funding Details:
Identification Number or DOI: https://doi.org/10.1016/j.biosystemseng.2019.11.004
URI: http://eprints.usq.edu.au/id/eprint/37608

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