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The objective of this study was to evaluate the performance of nutritional programming on growth and hematological indices of sterlet sturgeon (Acipenser ruthenus) during the larval stage by partial replacement of fish meal (FM) with soybean meal (S). Fish with initial mean weight of 0.32 ± 0.01 g were randomly distributed into twelve circular concrete tanks (260 fish per each tank) and fed four experimental diets with substitution levels of 0 (control/FM), 15% (S15), 30% (S30) and 45% (S45) of fish meal with soybean meal during three phases in three replicates. In phase 1 (programming), fish were fed four different diets for 28 days. All the groups were then fed with FM during intermediate phases and S45 at final phase (challenge) for 28 days. At the end of each phase, growth indices were measured. Hematological indices including hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration were assessed at the end of the challenge phase. The growth performance was not significantly different in either programming or intermediate phases (P > 0.05); however, final weight, weight gain, specific growth rate, and average daily growth were significantly higher in S45 than FM during phase 3 (P < 0.05). In intermediate phase, feed conversation ratio was significantly reduced in FM than the other treatments (P < 0.05). Moreover, no significant difference was indicated among the groups in hematological indices (P > 0.05). According to the obtained results, early nutritional programming could effectively enhance the adaptation of sterlet sturgeon to plant-based protein later in life. [ABSTRACT FROM AUTHOR]

Persian sturgeon (Acipenser persicus) is a unique and native species in the southern coasts of the Caspian Sea in Iran, but due to problems in adaptation to hand feed, it is received less attention from the sturgeon farmers. The aim of this study was to use chironomide as an initial food in transition to dry feed (weaning) and its effect on growth indices, survival, fatty acids profile and carcass analysis. Thus, Persian sturgeon larvae were reared for 11 days from the beginning of active feeding with 4 treatments including: 1 (Artemia + Daphnia), 2 (Artemia only), 3 (Artemia + chironomide) and 4 (chironomide only) and in the second stage for transition to the formulated diet, 300 Persian sturgeon with an average weight of 263.8 ± 2.3 mg (mean ± standard error) were reared with 3 replicates over 21 days using chironomide and formulated feed. Final weight, growth rate, and feed efficiency were significantly higher in treatment 4 than the other treatments (P < 0.05). Specific growth rate and mean body weight were higher in treatment 4 than the other treatments. Feed conversion ratio was the lowest in treatment 4 (P < 0.05). The results showed that the initial feeding with chironomide was effective on carcass analysis in the acclimation period, so that the fat and ash contents in fish fed chironomide was higher than the Artemia + Daphnia treatment (P < 0.05). Analysis of larvae at the end of the first stage showed the effect of live food on fatty acids profile in different treatments (P < 0.05). However, in the adaptation to dry feed, the results changed and no significant differences were observed among the treatments (P > 0.05). This study showed that the use of chironomide in the diet of Persian sturgeon at the start of feeding up to the adaption period can increase the DHA/EPA ratio, conversion of short-chain unsaturated fatty acids to long-chain. An increase in the ratio of n-6 to n-3, body fat content, growth and survival indices in the adaptation phase were recorded as well. [ABSTRACT FROM AUTHOR]