Effect of Stage of Lactation on Milk Yield and Composition of First Kidder Damascus does in the Sudan

The present study was conducted to evaluate milk yield and composition of Damascus does raised under Sudan condition. Thirteen Damascus does in first parity order were selected from a flock owned by the Mamlakat El-Nahal farm during the period from March to November 2009. The lactation period was divided into three stages viz: early (2nd - 9th wk), mid (10th - 17th wk) and late (18th - 35th wk). Milk yield and composition were monitored on weekly basis throughout the experimental period. The data were analyzed by Duncan Multiple Range tests using SAS. Milk yield was significantly (P < 0.05) higher in the early lactation stage (1.34±0.02 L), then it decreased gradually until the end of lactation (0.96±0.02 L). The milk composition (total protein 3.59± 0.03%, casein 2.87±0.025%, whey protein 0.72±0.007%, albumin 0.19±0.01 mg/1000g, B-lactoglobulin 0.27±0.003 mg/1000g, total solids 13.49±0.084% and solids not fat 9.11±0.049%) were higher during the early stage of lactation. Then were decreased (P > 0.05) during the mid lactation stage (total protein 3.27±0.02%, casein 2.60±0.014%, whey protein 0.65±0.004%, albumin 0.15±0.003 mg/1000g, B-lactoglobulin 0.24±0.001 mg/1000g, total solids 12.25±0.08% and solids not fat 8.40±0.03%). They were increased gradually during the late stage of lactation. The fat, lactose and ash content showed non significant variations between the stages of lactation. The present study concluded that Damascus does can be raised in Sudan with acceptable production. Moreover the different stages of lactation affected their milk yield and composition as thechemical constituents were reduced with the progress of lactation.