The effects of two diets, a control diet (commercial feed with 39% crude protein) and an experimental diet (prepared based on 42% soybean meal with 38% crude protein), on growth performance of western white shrimp (Litopenaeus vannamei) in six 0.4-ha-earthen ponds (three replications per treatment) with 25 per m2 density, were investigated. There was no significant difference in final weight (m...