Thesis (M.Sc.) - Cairo University - Faculty of Agriculture - Department of Animal Production

This study was carried out to determine the influence of lactation status and season of the year on the productive and physiological performance of Egyptian buffaloes. Twenty Egyptian buffalo heifers were chosen at their first season of calving. These buffaloes were reared under the same managerial and environmental conditions. Buffalo heifers were divided into four experimental groups. The first group was those lactating under hot conditions and the second group was those non-lactating under hot conditions. Whereas, the third group was those lactating under cold condition and the fourth group was those non-lactating under cold conditions. Blood plasma samples were collected and analyzed for some hematological, biochemical, and hormonal parameters. Results showed non-significant differences among all groups in total proteins concentration. Glucose level significantly higher in dry buffalo than lactating buffalo and significantly decreased under hot conditions compared cold conditions. Significant decrees was found in total lipids and cholesterol levels under hot condition than cold condition. Also, lactating buffaloes were lower in total lipids and cholesterol levels than dry buffaloes. Lactating groups recorded the lowest concentration of Ca⁺⁺, P⁺⁺⁺, K⁺ and Na+ and Na+, P⁺⁺⁺, K⁺ contents were significantly increased under hot conditions while Ca⁺⁺ content was significantly decreased. Both T3 and T4 concentration in buffaloes were significantly lower under hot conditions than cold conditions. Non-significant differences were found between the two seasons in protein, lactose and solids not fat contents. Milk fat and total solids percentages and daily milk yield were significantly increased during the cold conditions compared to hot conditions

Issued also as CD