Copper, manganese and zinc requirements in the diet of shrimp Penaeus indicus.

Abstract

Dietary requirements of copper, manganese, and zinc were investigated for the Indian white shrimp Penaeus indicus using purified diets. Feeding trials conducted on shrimp with an average weight of 70 mg for 45 days have shown that without supplemented copper, the diet produced higher growth (p > 0.05). However, the diet with 22.7 mg% copper gave the lowest feed conversion ratio (FCR) of 2.14 (P > 0.05) and higher survival rate (81.3%). Copper content in whole body of shrimp increased with dietary copper. Shrimp fed with diets having different levels of manganese grew better on the diet (control) that had 0.21 mg of manganese per 100 g. Higher levels of dietary manganese suppressed growth (P > 0.05). However, food conversion ratio (FCR) and survival rate improved when the diet contained 1.9 to 2.6 mg% manganese. In the case of zinc, the growth of shrimp improved with dietary zinc up to 23.6 mg% and declined thereafter (p > 0.05). However, the diet with 38.6 mg% zinc produced low FCR (p > 0.05). Zinc concentration in shrimp body increased with the dietary levels of the element, though the body ash showed a decreasing trend.