Abstract: The investigation of a suitable level of Holstein of crossbred Holstein in climate change situation was the aim of this study. The exceeded 8,000 records of milk yield from 2007-2009 were used. Temperature and relative humidity of each day from 2007-2009 were the weather data. Temperature and Humidity Index (THI) was calculated and compared by t-test. Milk production was divided into 3 groups followed by the different percentages of Holstein, G1 = % Holstein<80%, G2 = % Holstein from 80-89%, G3 = % Holstein≥90. Ordinary least square was used to estimate the effect of all fixed effects which included lactation, day in milk and the combination between the years and breed groups. The stability of the effect of combination between the years and breed groups were used to detect the ability to stand in climate change situation of each group of Holstein. THI was significantly increased each year from 86 in 2007 to 91 in 2009. The consistent effect on milk production was shown in only G2. The results of this study suggested that climate change situation obviously affected the production of dairy cows and that the suitable level of Holstein was in the range of 80%.
Amonrat Molee, Bordin Bundasak, Petladda Kuadsantiat and Plern Mernkrathoke, 2011. Suitable Percentage of Holstein in Crossbred Dairy Cattle in Climate Change Situation. Journal of Animal and Veterinary Advances, 10: 828-831.