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Abstract Physiological responses of Buffalo Native and Friesian cows to diurnal, monthly and seasonal climatic changes, as influenced by the type of housing or shading were studied at the Animal Production Farm of EI-Minia University. A total of 32, 2-3 months post-partum lactating animals in their second lactation were used as follows : 1. Eight Buffalo 00WS routinely housed in the stahle all the time. 2. Eight Friesian cows kept during the day under asbestos shed. J. Eigh~ Friesian cows kept during the day under linen textile shed. 4. Eight Native cows kept during the day under asbestos shed. Friesian and Native cows were routinely. turned into the stable overnight (5:00 p.m. to 9:00 a.m.), after which time they were turned outdoors to be kept under sheds, in the farm. R.T. and R.R. were recorded for all the animals three times daily at 8:00 a.m., 2:00 p.m. and 8:00 p.m. During the second year of this two years investigaation, (March 1984 to February, 1986),blood sampling of cows for haematocrit determinations was carried out monthly at mid-day (12:00 noon) in the day of test. After blood sampling, water consumption (second drinking) was recorded. Atmospheric temperature (A.T.) and R.H. % of EllMinia province, the experimental farm (outdoors), the stable (indoors) and under different types of sheds, were recorded. 1. There were diurnal (P ~ 0.01), monthly (P <.0.01), and seasonal (P < 0.01) variations in R.T. and R.R. for all experimental animals, in response to changing A.T. 2. There were species differences (P (0.01), breed differences (P (0.01), and differences due to housing (P < 0.01) or shading type (P~O.Ol), in the physiological responses, R.T. and R.R. of the experrimental animals, with varying A.T. 3. All experimental animals developed hyperthermia for at least nine months a year (from March through November) the magnitude of which was higher in the confinement, (in the stable) followed by the asbestos shading, but lowest for the linen textile shading. 4. Hyperthermia developed by animals, in response to rising A.T., was highest during summer and autumn, approaching critical levels (above 39°C, R.T.) during July through September, with the peak during August. 5. There were monthly (P<”O.Ol) and seasonal (P<’O.Ol) variations in the _ baematocrit of cattle(The highest values were during February (32.9 for Friesians and 34 % for Natives), while the lowest values were. during August, 28.3 % for Friesians, and 27.4 % in July for the Native cows. Thus indicating haemodiilution during hot summer and autumn months. 6. There were mont~ly (P I.. 0.01) seasonal (P <. 0.01) ,and breed ( P <..0.01) differences in water consumption by cattle.The largest values were during hot summer and Qutumn months. ~he water intake was doubled by Friesian cows during August, and by the Native cows during July and August. |