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Utilization of Feed and Growth Performance of Mud Crabs: The Effect of Herbal Extracts as Functional Feed Additives
Get PDFThis study aimed to analyze the effect of herbal extracts as functional feed additives on the utilization of feed and growth performance of orange mud crabs (Scylla olivacea). The test animals used were 60 crabs for each treatment dose. The crabs are kept individually in a crab box which was placed on a floating bamboo raft. This was to enable floating on the surface of the pond water which had a depth of ±80 cm. The treatments tested were four doses of a combination herbal extract from Morus alba, Curcuma xanthorrhiza, and Boesenbergia rotunda, namely 0, 200, 400, 600 mg kg-1 of feed. Formulated feed with the protein content of 41.93%, fat 7.43%, Nitrogen Free Extract (NFE) 29.33%, and crude fiber 7.82% was given at a dose of 5% body weight every day. Based on one-way ANOVA, the results showed that the dose of herbal extracts influences the feed utilization and growth performance of mud crabs. The dose of herbal extract 600 mg kg-1 of feed provided higher feed utilization and growth performance (LSD Test: P<0.1). Significant differences were found between feed utilization and growth performance of mud crabs after molting and non-molting. In molting mud crabs, treatment with herbal extract 600 mg kg-1 obtained an average weight gain of ±60.73 from the initial weight, compared to control crabs (without herbal extracts) gaining an average weight gain of ±43.73%. However, in non-molting crabs, ±5.44 and ±6.42 weight gain was observed, respectively. Significant differences also occurred between treatments for specific growth rates, feed consumption, feed efficiency, and condition factors. These results provided information that herbal extracts are potentially as feed additives to increase feed utilization and growth performance, as well as stimulate molting in crab cultivation
Effects of acute ammonia exposure and post-exposure recovery on nonspecific immunity in Clam Cyclina sinensis
Get PDFThis study aimed to assess the toxicity of ammonia on clam Cyclina sinensis and the post-exposure recovery. With increased exposure to TAN, the alkaline phosphatase (AKP) activities after exposure showed a trend of growing initially and subsequently decreasing, whereas the AKP activities after post-exposure recovery showed an increasing trend. The AKP activities after post-exposure recovery were significantly higher than those in control. The acid phosphatase (ACP) activities in T1 and T2 after post-exposure recovery were higher than those in the control, whereas the ACP activities in T3, T4, and T5 after post-exposure recovery were significantly higher than those in the control. The lysozyme (LZM) activities in T1 and T2 after exposure were significantly higher than those in control, whereas the LZM activities in T3, T4, and T5 after exposure were significantly lower than those in the control. Overall, ACP and LZM in the clams exposed to a low level of TAN (≤ 40 mg/L) can recover to the normal levels completely. However, a 48h recovery period scarcely seems adequate to compensate for AKP, ACP, and LZM activities in the clams exposed to a high level of TAN (> 40 mg/L)
Association of a single nucleotide polymorphism of the Leptin gene with growth traits in Takifugu rubripes
Get PDFLeptin (LEP) plays a role in animal growth, appetite regulation, energy partition, and body composition. In this study, 296 cultivated Takifugu rubripes individuals were screened for LEP gene polymorphisms using PCR-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing. Two single nucleotide polymorphism (SNP) mutations were detected in T. rubripes LEP gene: C/G at position 232 nucleotide (nt) and C/T at position 310 nt. One-way ANOVA of the SNPs and growth traits showed that genotype CC of primer L2 had a significantly higher body length (BL), body weight (BW), and absolute growth rate of BL (ABL) and BW (ABW) than genotypes CG and GG (P<0.05). The genotype frequencies of CC, CG, and GG were 61.15%, 35.14%, and 3.17%, respectively. Genotype CC at the C232G site was advantageous and significantly associated with growth traits. This site would be an excellent molecular marker to select and cultivate through statistical analysis. Additionally, the second unmutated and mutated mRNA structures were compared and analyzed. These results indicate that the T. rubripes LEP gene may be a candidate for these growth traits
