Abstract:A study was conducted to investigate the effect of feeding frequency on growth, reproductive performance, body composition and digestive enzyme of broodstock Litopenaeus vannamei. Experimental broodstock were fed with Nereis succinea for 60 days. Before the start of the experiment, the unilateral eye socket of each broodstock was placed on the eye as an individual marker and the initial body length and weight of each female were determined. The average initial body weight was 41.78 g and the average initial body length was 15.80 cm. The broodstock were randomly divided into three round pools, each with 40 shrimps. Three groups of broodstock were fed to satiation in two times per day, three times per day and four times per day, which were represented by F2, F3 and F4 groups, respectively. Results showed that the feeding amount of broodstock increased gradually with the increase of feeding frequency, and the F2 group was significantly lower than that in group F4 (P<0.05), but there was no significant difference between the F3 group and the F2 group (P>0.05). The weight gain and body length growth of broodstock increased first and then decreased with the increase of feeding frequency, but there was no significant differences among treatments (P>0.05). Reproductive performances of Litopenaeus vannameimei were not affected by different feeding frequency in current study (P>0.05). There were no significant differences in single fecundity, relative fecundity, the number of nauplius stage I, hatching rate, the number of zoea stage metamorphosis rate (N1-Z1), gonadosomatic index(GSI),first spawning time and the spawning intervals (P>0.05). The body composition of Litopenaeus vannamei including moisure, crude protein, crude Lipid and ash were not affected by feeding frequency (P>0.05). The results showed that the activity of trypsin and lipase of hepatopancreas in the F2 group was significantly lower than that in the F3 and F4 groups (P<0.05), but there was no significant differences among the activity of pepsin and amylase in different experimental groups (P>0.05). Based on the results of this experiment and the actual production conditions, the optimum feeding frequency of nutrient fortification in Litopenaeus vannamei broodstock is suggested to be 2 times per day.
