Effect of Temperature Cumulation on Milk Yield of Czech Fleckvieh-Simmental Cattle

Abstract

The aim of this study was to asses the effect of temperature cumulation on milk yield of Czech Fleckvieh-Simmental cattle. Experiment for this study was executed on private farm in Czech Republic with permanently open-sided barn, in which were cows stabled (49o12'36.7"N 16o23'42.1"E). Cows were stabled in free stall box system. Experiment lasted three months (May-July) of 2016. In total 114 cows were include in this study. They were divided according to yield to three groups: more than 25 kg of milk per day, 20.1-24.9 kg of milk per day and less than 20 kg of milk per day. The data loggers placed inside the stable collected data about temperature every 30 minutes. Data about milk yield were obtained from software in milk parlour. After data were collected, the sum of effective temperatures (SET) was calculated. The SET was calculated for temperatures surpassing 21 oC. Data shows that all groups were affected by rising SET. The group with yield above 25 kg of milk per day was the most affected by the high SET (r = MINUS SIGN 0.4931) in contrary with the group with less than 20 kg of milk per day (r = MINUS SIGN 0.1380). Our result suggest, that the SET might be better marker for evaluation of the impact of heat stress than temperature itself. The results of this paper also shows, that the high-yield cows are affected by cumulation of temperature more.