Effects of mild heat stress periods on milk production, milking frequency and rumination time of grazing cows milked by an automatic milking system | Effets de stress thermiques modérés sur la prodution laitière, la fréquence de traite et le temps de rumination de vaches au pâturage traites par un robot de traite
2014
Lessire, Françoise | Hornick, Jean-Luc | Dufrasne, Isabelle
anglais. peer reviewed
Afficher plus [+] Moins [-]anglais. Grazing dairy cows milked by an automatic system (AS) experienced mild heat stress (HS) periods, twice during the summer. The daily temperature humidity index (THI) during these periods were higher than 72. Milk production, as well as milking frequency, rumination time and milk fat to protein ratio (F/P) during these periods were compared to adjacent periods with mean THI of 61. The daily milking frequency, the total number of visits to AS and the milk production were significantly higher in HS periods (2.12 vs 1.97, 2.99 vs 2.69, and 19.7 vs 18.5 kg milk per cow, respectively). There were significant interactions between times and periods for milking frequency and number of visits, while the daily rumination time was significantly lower (339 vs 419 min) and the F/P in milk tended to be decreased (1.17 vs 1.23). These results could be explained by changes in cow behaviour during HS periods.
Afficher plus [+] Moins [-]Autograssmilk
Afficher plus [+] Moins [-]Mots clés AGROVOC
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