Synchronous Least-Cost Ration Formulation for Lactating Barki Ewes using Nonlinear Programming Journal title: Journal of Animal Production Advances Authors: A. A. Aboamer , H. M. El-Sayed , S. A. H. Abo El-Nor , M. M. Khorshed , A. M. Kholif , I. M. Khattab... Subject(s):