Original scientific paper
https://doi.org/10.15567/mljekarstvo.2017.0203
The differences in heat stress resistance due to dairy cattle breed
Vesna Gantner
; J.J. Strossmayer University of Osijek, Faculty of Agriculture, Kralja Petra Svačića 1d, 31000 Osijek, Croatia
Tina Bobić
orcid.org/0000-0001-9975-1258
; J.J. Strossmayer University of Osijek, Faculty of Agriculture, Kralja Petra Svačića 1d, 31000 Osijek, Croatia
Maja Gregić
; J.J. Strossmayer University of Osijek, Faculty of Agriculture, Kralja Petra Svačića 1d, 31000 Osijek, Croatia
Ranko Gantner
; J.J. Strossmayer University of Osijek, Faculty of Agriculture, Kralja Petra Svačića 1d, 31000 Osijek, Croatia
Krešimir Kuterovac
; Inagra Ltd, J.J. Strossmayera 341, 31000 Osijek, Croatia
Klemen Potočnik
; University of Ljubljana, Biotechnical faculty, Department of Animal Science, Groblje 3, Domžale, Slovenia
Abstract
Considering the rapid climate changes worldwide, with the purpose to reduce financial losses for dairy farmers and enable a more sustainable farming as well, there is an increasing necessity to implement breeding values for heat resistance in breeding strategies. The estimation of breeding values requires a determination of temperature-humidity index (THI) threshold value. Therefore, the objective of this study was to determine the temperature-humidity index (THI) threshold values for daily milk yield, daily fat and protein content of milk produced by Holsteins and dairy Simmentals in Croatian farms. With that purpose, 1.070,554 test-day records from 70.135 Holsteins reared on 5.679 farms and 1.300,683 test-day records from 86.013 Simmentals reared on 8.827 farms in Croatia were compared to records of ambient temperature and relative humidity collected in the barn, during regular milking recordings from January 2005 to December 2012. Accordingly the following conclusions could be drawn: threshold values for daily milk yield were highly dependant on the parity and breed (Holsteins: 68, 69 and 72 for 1st, 2nd, 3+ parity; Simmentals: 77 for 1st); daily fat and protein contents showed a highly significant decrease due to heat stress condition (THI in 66-80) in both, Holstein and Simmental cows, and in all parity classes; multiparous cows were more resistant to heat stress than primiparous; Simmental cows were more resistant to heat stress than Holsteins.
Keywords
dairy cattle; Holstein; Simmental; heat stress; threshold value
Hrčak ID:
180151
URI
Publication date:
19.4.2017.
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