RESUMEN
Present experiment was conducted on sixty Murrah buffalo divided into three groups : pregnant, lactating and involution stage/Dry stage. No distinct lobulation was observed during nonlactating early pregnant stage. The ratio between maximum diameter of lobule in nonlactating mid and late pregnant stage was 4:5. Mammary lobules were oval to polygonal in shape. In lactating stage the approximate ratio between maximum diameter of lobule in colostrum stage and three months of lactation were 2:1. The number of alveoli were maximum during colostrum phase and reduced from colostrum stage to ten months of lactation. Highly significant statistical difference in the diameter of lobules and number of alveoli was noticed during different stages of lactation from colostrum to ten month. The number of alveoli was minimum during nonlactating nonpregnant stage from one to two month