THE PERFORMANCE OF HOLSTEIN COWS UNDER EL-FAYOUM CONDITIONS

Abstract

The present study was carried out using eight Holstein cows at experimental research station, supervised by The Department of Animal Science College of Agriculture, El-Fayoum, Cairo university. This work included four cows in the first parity and four cows in the second parity. Milk samples were taken fortnightly from evening and morning milking of .each cow, and analyzed for butter fat, protein, lactose, solids not-fat, total solids, ash, calcium, and phosphorus. The effects of the parity, stage of lactation and milking time on the milk yield and the composition of Holstein milk have been investigated, however, the correlation between the milk yield and its constituents were also studied. The relationship between partial milk yield (30, 60, 90 and 120-days milk yield) and milk yield was calculated. Blood samples were taken from cows fortnightly after evening and morning milking whole blood samples were analyzed for serum, total protein, albumin, globulin(was calculated by the difference between total protein and albumin), albumin/globulin ratio, glucose, cholesterol, triglycerides, calcium, phosphorus and calcium/phosphorus ratio were also calculated. The effects of parity, stage of lactation and milking time on blood serum constituents of Holstein cows have been also investigated. The suitability of some phenotypic traits as predictors for dairy performance of the experimental animals were studied. Additionally, eight udder and body measurements were taken at the end of the first month, then weekly till the 2ih week oflactation period for the first and second parity. The relationship between body and udder measurement and total milk yield was also calculated. The relationship among different udder and body measurements was calculated.