In this paper, an artificial neural network (ANN) based on hybrid algorithm combiningparticle swarm optimization (PSO) with back-propagation (BP) is proposed to forecast thedaily streamflows in a catchment located in a semi-arid region in Morocco. The PSOalgorithm has a rapid convergence during the initial stages of a global search, while theBP algorithm can achieve faster convergent speed around the global optimum. By combiningthe PSO with the BP, the hybrid algorithm referred to as BP-PSO algorithm is presented inthis paper. To evaluate the performance of the hybrid algorithm, BP neural network is alsoinvolved for a comparison purposes. The results show that the neural network model evolvedby PSO-BP algorithm has a good predictions and better convergence performances

We determined milk intake and growth rate of fat-tailed Awassi ram lambs from birth to 30 days of age when sucking ewes that were grazing natural green pasture in the semi-arid Negev. The conversion of milk and energy intake to body mass and body solids gain in the lambs were calculated. Annual rainfall and, as a consequence, pasture availability were below average during the study. Body mass at birth was 4·22 (s.d. 0·71) kg and at 30 days was 12·10 (s.d.1·22) kg for an average daily gain of 256 (s.d.33) g/day. Of the 256 g/day, 100 (s.d.12·3) g/day were body solids, and for every unit body mass increase, proportionately 0·391 was body solids. Milk and energy intakes averaged 1·34 (s.d.0·23) l/day and 5·66 (s.d.0·97) MJ/day, respectively. The volume of milk intake per kg increase in body mass and body solids were 5·2 l and 13·4 l, respectively, whereas, the energy intake per kg increase in body mass and body solids were 22·1 MJ and 56·6 MJ, respectively. Of the total metabolizable milk energy intake, proportionately 0·46 was converted to body energy of the lamb. Although dry matter intake of the ewes was insufficient to prevent body mass loss, they produced sufficient milk to support a relatively high lamb growth rate, presumably by mobilizing fat reserves in the tail.