Chemical composition, hormonal levels and immunoglobin G concentration in colostrums, milk and blood plasma of Egyptian buffaloes following calving.

The formation of colostrum in buffalo udder occurs during the first 5?7 days after calving. Its composition is similar to that of blood and differs significantly from milk. The present study was planned to study the variations in the levels of some hormones in colostrum, milk and blood plasma of Egyptian buffaloes. Results demonstrate that, the chemical composition of colostrum (dry matter, solid non-fat extract, lactose, milk fat and protein) changes very rapidly with time, so that by few days post partum it is already similar to that of normal milk. Concentrations of IGF-1 were higher in colostrum than in mature milk. leptin concentration was 69% lower in mature milk than in colostrum (5.53±1.01) at birth vs. 1.68±0.69 ng/ml at one week), while no significant differences were observed during the first month of lactation. Leptin daily secretion in mature milk was lower than in colostrum . Concentrations of IgG in colostrum averaged 3260.5mg/dl at the zero time, and then decreased to 2654.0, 1900.5 and 1325.25 at 3, 6 and 24 hours later after parturition. Plasma IGF-1 concentrations were increased during one week then fell slightly .The plasma leptin concentrations showed obvious decrease from(2.38±0.93 ng/ml) at birth, to(1.87±0.32 ng/ml) at four weeks.