Popis: |
Penaeus monodon stocked in ponds at 8000/ha were fed four types of farm-made feeds starting on day 16 of a 4-month culture period. The feeds were golden apple snail alone or in combination with cooked cassava or maize, or maize only. Mixed feeds resulted in significantly higher production, growth, and better size-frequency distribution of shrimp. Survival (88–99%) was not significantly different among the treatments. Maize alone or snails alone were inadequate. Presumably, the high amount of carbohydrate in cassava (92%) or maize (87%) provided the needed energy, and the high protein content of golden snail (54%) was available for growth. The fatty acid profile of the golden snail shows that it is a good source of 18:2 n -6, 18:3 n -3, and 20:5 n -3 which are essential fatty acids for P. monodon . The golden snail, with an essential amino acid index (EAAI) of 0.84, is a useful alternative source of protein for tiger shrimp. Feeding shrimps with golden snails and cassava yielded the highest net income (P48797/ha-crop) and return on investment (ROI = 206%) better than feeding with maize alone (net income = P23190/ha-crop; ROI = 120%), an industry practice. If shrimp farmers use golden snails as direct feed or as a feed ingredient, the problem of snail infestation in ricefields may be reduced. Snails will no longer be viewed as pests but rather as a resource which has economic value. |