COMPARISON BETWEEN FRIESIANS AND WATER-BUFFALOS IN GROWTH-RATE, MILK-PRODUCTION AND SOME BLOOD-CONSTITUENTS, DURING WINTER AND SUMMER CONDITIONS OF EGYPT

Twenty Friesian (group 1) and 20 buffalo (group 2) calves and 14 of each of lactating Friesians (group 3) and lactating buffaloes (group 4) were maintained in middle of winter conditions of Egypt for 2 months. The calves (groups 1 and 2) were of similar age (6 to 7 months) and average body weight (120 kg). The lactating animals were in the fifth season of lactation, non-pregnant, in mid lactation and yielded 12 to 14 kg milk on average daily. Similar groups of animals of the same types (groups 5, 6, 7 and 8, respectively), numbers, live body weights and physiological status were maintained under hot summer conditions for 2 months. The effect of hyperthermia during summer season on Friesians and buffaloes compared with winter was also studied. The results showed that buffaloes were more tolerant than Friesians to the environmental conditions of Egypt. In winter, buffalo calves had poorer (P < 0.05) food efficiencies (kg gain per MJ net energy), higher dry matter intakes (DMI, P < 0.05) and total lipids in the plasma (P < 0.01) than Friesians, while the contrary occurred in total proteins, albumin, phospholipids and cholesterol (P < 0.05). In summer, growth rate and the concentrations of total lipids, phospholipids and cholesterol in the plasma were higher (P < 0.01), and total proteins and albumin were lower (P < 0.01) in buffalo than in Friesian calves. In summer, in Friesians, both DMI and growth rate decreased (P < 0.05) and food efficiency as kg weight gain per MJ net energy was poorer (P < 0.05). In the plasma total proteins and albumin increased (P < 0.01) but haematocrit \%, phospholipids and cholesterol decreased (P < 0.05). In buffalo calves, only total proteins and albumin increased (P < 0.01) due to heat stress. In lactating buffaloes, food efficiency was poorer (P < 0.01) and DMI and plasma haematocrit \% were significantly higher, while the concentrations of total proteins, globulin, phospholipids and cholesterol in the plasma, and milk yield were significantly lower than in lactating Friesians in the winter season. Lactating buffaloes were poorer (P < 0.01) in food efficiency and had lower concentrations of total proteins, globulin and cholesterol than lactating Friesians in the summer (P < 0.01).