EFFECT OF NATURAL AND CONTROLLED CLIMATES OF SAHARA ON VIRTUAL TRITIUM SPACE IN FRIESIANS AND WATER BUFFALOES

Twenty-eight dry Friesian cows and 33 dry Water Buffalo cows were used in determining body water, live body weight, and dry body weight (live body weight—total body water) in winter, spring, and summer. Another four dry Water Buffaloes were exposed to comfortable and hot climates in a climatic laboratory each for one week, when these measurements were made. In Friesians, dry body weight was lower in summer than in either winter or spring (P < 0.05), whereas it did not change significantly in Water Buffaloes, indicating that Buffaloes are more heat tolerant than Friesians. Total body water, in liters, and liters/100 kg dry body weight in Friesians increased from winter to spring (P < 0.01 and 0.10) and from winter to summer (P < 0.01), but when expressed as liters/100 kg live body weight it increased only from winter to summer (P < 0.01). In Water Buffaloes, body water in liters, liters/100 kg live body weight, and liters/100 kg dry body weight increased from spring to summer (P < 0.01, 0.05, and 0.01) and from winter to summer (P < 0.05, 0.10, and 0.05), indicating that Water Buffaloes increased their body water at ambient temperature and relative humidity higher than those for Friesians. Live body weight changed inconsistently with heat, due to the interaction between body water and dry body weight changes with heat. Results of the climatic chambers experiment were in accordance with those of the season study. © 1969, American Dairy Science Association. All rights reserved.