mohamad mazandarani

The necessity of the present study was to compare the reproductive performance and growth of offspring of common carp (Cyprinus carpio) breeders imported from China (first generation) and conventional breeding. For this purpose, before the final mating of breeders, 10 male and female breeders who were the same age and received the same diet were randomly selected from each group and separated to reduce the probability of spawning in the breeding tank to zero. After maturation, LHRH along with metoclramide was used for two-stage injector in female and one in inducer in male. Then, reproductive performance including yield percentage, hatching percentage, fertilization percentage, larval survival percentage and also progeny growth performance including feed conversion ratio and specific growth rate for each group were examined. In the results of reproductive yield, the amount of productive weight in common carp was higher and showed a significant difference compared to F1 generation carp (P <0.05). Egg rate, yield percentage, number of eggs, number of eggs per gram, percentage of fertilization, number of fertilized eggs, hatching percentage, number of hatched larvae, number of hatched larvae and incubation survival in F1 generation carp group more than common carp group Was and had a significant difference (P <0.05). Feed conversion ratio and specific growth rate of F1 generation carp increased compared to conventional farmed carp and showed a significant difference (P <0.05). Therefore, the use of F1 generation carp to improve growth factors and reproductive conditions is recommended to increase economic productivity.Keywords: F1 generation carp, common farmed carp, growth, reproductive performance

In this study, the effects of replacing fish meal with soybean meal on growth performance, feed efficiency, body composition, fatty acid profile and gut lactic acid bacteria of beluga sturgeon, Huso huso. Nine diets were formulated (40% crude protein) in which soybean meal was replaced by fish meal at 0 (control), 40 and 80% supplemented and with three multi-enzyme level 0, 1 or 2 g/kg of Kemin multi-enzyme. Fish were fed on experimental diets for 12 weeks at 1% body weight. Addition of soybean meal decreased growth performance and the effect was more pronounced when with increasing levels of soybean meal (P<0.05) and minimum final weight occurred at 80% of fish meal replaced by soybean meal. Body fatty acid composition was affected by dietary treatments. Fish fed the control diet; diets with enzyme supplementation (without the addition of soybean meal) as well as diets 4 and 5 (40% soybean meal; 0 or 1 g/kg enzyme) had the highest n-3 and eicosapentaenoic acid. In contrast, soybean meal at an inclusion level over 40% negatively influenced n-3 fatty acid. The lowest content of eicosapentaenoic acid and docosahexaenoic acid and n-3 fatty acid was observed in fish fed diets with 80% soybean meal without the inclusion of enzyme (treatment 7). Addition of soybean meal at both 40 and 80% replacement level regardless of enzyme supplementation increased the number of gut Lactococcus lactis, Lactobacillus carvatus, Pediococcus pentaseceous, Lactobacillus plantarum, total aerobic counts and total anaerobic counts. The highest number of bacterial counts occurred in diet containing 80% soybean meal with 2 g/kg enzyme (treatment 9) (P<0.05). The results of this study indicated that soybean meal with enzyme supplementation at 2 g/kg can substitute 40% for fish meal in commercial diets of great sturgeon.