Résumé
The effect of different lecithin sources and presentations on growth, food conversion ratio and survival of P. vannamei (290 mg +/- 0.02) was studied. The bioassay was designed in order to compare different dietary levels and different quality of lecithin. Squid lecithin, crude soybean (7), deoiled soybean lecithin (3.48) in combination with fish oil or squid neutral lipids, in a partially dilapidate formula. The isoenergetic diets were fed ad libitum to four replicate groups (tanks) of 15 shrimps each (5 x 4 x 15), during 28 days. The result of the bioassay with the partially dilapidate formulas was; the best growth rate (191) and FCR (1.69 +/- 0.041) were obtained with the diet containing 7 of soybean crude lecithin as the unique lipid source. Followed by the diet countering 3.94 deoiled lecithin and 2.42 Menhaden oil (172 and 2.03 +/- 0.054 respectively). As expected, the worst results were obtained without the dietary lecithin 121 and 2.42 +/- 0.129). Crude soybean lecithin alone covered the phospholipid and neutral lipids requirements as well as the combination of deoiled soybean lecithin with fish or squid oil.
Sujets)
Animaux , Aliment pour animaux , Régime alimentaire , Penaeidae , Phosphatidylcholines , Matières grasses alimentaires , Huiles de poisson , Huile de soja , Prise de poidsRésumé
Juvenile prawn Macrobrachium carcinus were fed two different diets: restaurant by-products (diet I) and fish and vegetable market by-products (diet II). These diets were evaluated by proximal analysis, assimilation efficiency and the factor conversion rate (FCR). Diet I registered a higher efficiency, but there was no difference in the growth rate. The growth mean (G. L.) for three months was 0.254 +/- 0.13 cm (diet I) and 0.191 +/- 0.1 cm (diet II). The conversion rate was good for both, suggesting that 6 to 7 kg of food are needed to obtain 1 kg of prawn. Survival was 76 PER CENT and 100 per cent for diets I and II, respectively