摘要：Background: Synchronization the rate of which dry matter and crude protein degraded at the rumen significantly affects the synthesis of microbial protein and thus the efficiency of feed utilization . During previous study a new software application "Lacto-sheep" had been developed to facilitate the formulation of the least cost ration considered this important factor. So that formulation of a synchronous least cost ration is possible and not difficult. This study was carried out to investigate the advantages of feeding synchronous least cost ration as an alternative to the traditional least cost ration on nutrients digestibility and milk production and its constituents. Materials and Methods: The kinetics of dry matter and crude protein disappearance and ap proximate analysis were determined for each feed ingredients used. Then, using our feed formulation software "Lacto-Sheep" two diets; traditional least cost and synchronous least cost ration were formulated and fed to two groups of multiparous lactating Barki ewes (5 ewes each), suckling single with an average body weight (35.10±2.50 kg) using completely random design. Experiment started 2 weeks after lambing and lasted 60 days. Results: The synchronous least cost ration contained variety of protein sources compared with the least cost ration, which did not contain any rich source of protein (soya bean or cotton seed meal) thats because the cost of feed is the main limiting factor regardless optimizing feed utilization . Digestion coefficient of crude protein was slightly improved in group fed synchronous least cost ration. In addition, milk production and its components were also slightly higher. However, the differences were not significant. Conclusion: Based on the results obtained from this study, synchronous least cost ration seemed to be more practically appropriate ration for feeding lactating Barki ewes.
