EVALUACIóN DE LA RESTRICCIóN ALIMENTICIA SOBRE EL DESEMPE？O PRODUCTIVO Y FISIOLóGICO EN JUVENILES DE CACHAMA BLANCA, Piaractus brachypomus, EN CONDICIONES DE LABORATORIO

the general purpose of this experiment was to evaluate the effect of food restriction on the productive and physiological performance of cachama blanca juveniles and on the content of protein and energy in their muscles. 64 animals, with an average weight (p) of 58.40 ± 6.56 g and 14.65 ± 0.75 cm of total length (lt), were divided at random in 16 tanks. during eight weeks the animals received the following treatments: daily feeding; treatment 1 (t1): one day of fasting followed by one day of feeding; treatment 2 (t2): three days of fasting and two days of feeding; and treatment 3 (t3): two days of fasting and three days of feeding. food containing 35% protein, at 3% of the total biomass was supplied twice a day. at the end of the experimental period the animals were anaesthetized and blood samples were taken in order to evaluate different metabolic and hormonal parameters. later, the animals were sacrificed, weighted and measured. the viscera, liver and a portion of white tissue were used in order to determine protein and energy. the experimental design was done completely at random with three treatments and four repetitions, each done with four animals. at the end of the experiment, survival rate was calculated. the results did not show significant differences in most of the parameters analyzed. it was concluded that the juveniles of cachama blanca are capable of adapting metabolically to the partial lack of food and of optimizing their performance response.