Assessment of differently processed feed pea (Pisum sativum) meals and canola meal (Brassica sp.) in diets for blue shrimp (Litopenaeus stylirostris)

The nutritional value of whole, dehulled, extruded, dehulled-extruded and micronized feed peas, and extruded canola meal, included at a 30% concentration as ingredients in diets for juvenile blue shrimp was assessed. Pea meals replaced a portion of soybean meal and wheat (1:3 parts) on an isonitrogenous and isoenergetic basis, and similarly extruded canola meal replaced a portion of soybean meal, fish meal and wheat (1:2:3 parts) of a control diet. After 28 days, the shrimp almost tripled their weight on the experimental diets. Performance was unaffected by dehulling, except for a slight increase in feed consumption and lower protein efficiency ratio (PER), Extrusion cooking had no effect on growth and survival but significantly improved feed conversion and PER. The micronized pea diet produced the highest feed intake and growth rate. Response to the diet containing extruded canola meal was similar to that of the control diet. ingredient apparent dry matter digestibility (IADMD) ranged from 80.7% for micronized peas to 92.4% for dehulled-extruded peas, and was 79.4% for extruded canola meal. Higher IADMD coefficients were obtained for extruded pea meals as a result of starch gelatinization. Ingredient apparent protein digestibility (IAPD) ranged from 79.1% to 85.4% and did not differ significantly amongst the test meals. The test ingredients also conferred differential water stability properties with the whole-extruded peas ingredient containing diet having the lowest dry matter and crude protein (CP) loss following a I-h immersion in water. This study showed that whole raw feed pea is a very acceptable ingredient for blue shrimp diets; extrusion cooking improved feed conversion ratio and PER, and micronizing peas enhanced feed intake, while dehulling had no effect. (C) 2001 Elsevier Science B.V. All rights reserved.