Water buffaloes productive performance in Egypt as affcted by season

The present study includes 20 lactating buffaloes to estimate the effects of calving season and growth stage on milk production perfonnance. In winter a total of 10 winter calving buffaloes (WCB) were assigned to two groups: (a) growing lactating buffaloes (GLBW, n = 7) and (b) mature lactating buffaloes (MLBW, n = 3). As well as, in summer, a total of 10 summer calving buffaloes (SCB) were assigned into two groups: (a) growing :actating buffaloes (GLBS, n = 4), (b) mature lactating buffaloes (MLBS, n = 6). Milk samples were collected weekly from each animal. Tre was measured and blood samples were collected from animals of each group at test day till the end of lactation period. Plasma samples were stored until subsequent analysis for ALT, AST, ALP, Albumin, Total protein, Cholesterol, and Triglycerides levels. Data were statistically analyzed using SPSS program to find out the variance between season of calving and between growing stages. Results indicate that, THI values were higher than 70 in summer and less than 70 in winter. Tre was not affected significantly by Parity and prevailing environmental conditions. SC buffaloes produced most of their milk in winter when Ta was almost being around the thermoneutral zone and therefore produced more milk than WC buffaloes. Mature buffaloes as well as produced more milk than growing buffaloes. SC had longer lactation period than WC buffaloes. Milk protein % was significantly higher in SC than WC buffaloes, whereas, milk lactose, fat and TS % did not differs between WC and SC buffaloes. ALT was significantly higher in SC than WC buffaloes. MSC buffaloes showed significantly higher ALT than growing buffaloes in both summer and winter. AST and ALP showed no significant differences. TP and globulin were significantly higher in SC than WC buffaloes with no significant between growing and mature' buffa1oes. Yet, albumift was not significantly differed between WC and SC buffaloes. AlG ratio was within normal values and did not differ significantly between groups or subgroups. In general, WC produced higher milk and milk components than SC buffaloes. MLB produced more milk and milk components within calving season. Plasma AL T, AST. and ALP levels followed milk production in all groups.