LAUSR

ABSTRACT The experiment was carried out to investigate the changes in physiological parameters and blood flow during different seasons (winter, thermo-neutral and summer) in Sahiwal (SW), Tharparkar (TP), Gir (GR) and Karan Fries (KF) dairy cows. Four healthy lactating cows from each breed were selected from a herd of Livestock Research Center, NDRI, Karnal. All animals were fed as per the ICAR (2013) feeding standard. Physiological parameters like respiration rate, pulse rate, blood pressure, rectal temperature, skin surface temperature (head, shoulder and flank), blood flow (dorsal, abdomen, ear and mammary gland) were recorded on days 30, 45 and 60 postpartum. Respiration rate was highly significant (p < 0.01) between seasons and was significant (p < 0.05) between breeds. Pulse rate was significant (p < 0.05) between breeds and between days of experiment and was highly significant (p < 0.01) between seasons. In the present experiment, both diastolic and systolic pressure differed significantly (p < 0.05) between days and between breeds and was highly significant in the summer than winter and thermoneutral. Rectal temperature was increased non-significantly between season and between days in all breeds. The skin surface temperature among the different parts of the body differed significantly (p < 0.05) between days and between breeds and was highly significant (p < 0.01) between seasons. Blood flow was highly significant (p < 0.01) between breeds and between days during the summer and was highly significant (p < 0.01) between seasons. It was concluded that the physiological parameters like respiration rate, pulse rate, blood pressure, skin surface temperature and blood flow give an immediate response to climatic stress and thus to the level of comfort of the animal, and summer season is more stressful as compared to winter and thermoneutral season, which affects the production in the summer season. Therefore, these parameters are important in measuring the comfort level of the animal and thus the production potential of the animal.