scholarly journals Comparison of Some Biological Parameters between Young Grass Carp, Ctenopharyngodon idella (Valenciennes, 1884) fed on Artificial Diet and Alfalfa inEarthen Ponds at Basrah, Iraq

2022 ◽  
Vol 6 (1) ◽  
pp. 1-13
Author(s):  
Sadik Muhammed

The current study aims to compare the relationships of some biological parameters of young grass carp, Ctenopharyngodon idella (Valenciennes, 1844) fed on artificial diet and alfalfa in earthen ponds. These parameters included length-weight relationship, relative length and weight of the alimentary canal, condition factor and survival rate. Results of lengthweight relationship showed that no significant differences (P>0.05) were recorded for the t-test for the ideal value of 3 for fishes fed on artificial diet or alfalfa plant. The condition factor of young grass carp fed on artificial diet ranged between 0.021 to 1.074, while for fishes fed on alfalfa plant was 0.023 to 1.270 for allometric and Fulton’s condition factor, respectively. Also, there was no significant difference (P>0.05) for fishes fed on both diets in all biological parameters, the relative length of the alimentary canal for fishes fed on artificial diet (1.65) and on alfalfa plant (1.69), while the relative weight of the alimentary canal were 0.0285 and 0.0218 for fishes fed on both diets, respectively. Results also showed that the Zihler coefficient were 7.43 and 7.62, respectively. The survival rate was 100% for both treatments.

Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 41
Author(s):  
Changyong Mu ◽  
Qiwang Zhong ◽  
Yan Meng ◽  
Yong Zhou ◽  
Nan Jiang ◽  
...  

The grass carp reovirus (GCRV) causes severe hemorrhagic disease with high mortality and leads to serious economic losses in the grass carp (Ctenopharyngodon idella) industry in China. Oral vaccine has been proven to be an effective method to provide protection against fish viruses. In this study, a recombinant baculovirus BmNPV-VP35-VP4 was generated to express VP35 and VP4 proteins from GCRV type Ⅱ via Bac-to-Bac baculovirus expression system. The expression of recombinant VP35-VP4 protein (rVP35-VP4) in Bombyx mori embryo cells (BmE) and silkworm pupae was confirmed by Western blotting and immunofluorescence assay (IFA) after infection with BmNPV-VP35-VP4. To vaccinate the grass carp by oral route, the silkworm pupae expressing the rVP35-VP4 proteins were converted into a powder after freeze-drying, added to artificial feed at 5% and fed to grass carp (18 ± 1.5 g) for six weeks, and the immune response and protective efficacy in grass carp after oral vaccination trial was thoroughly investigated. This included blood cell counting and classification, serum antibody titer detection, immune-related gene expression and the relative percent survival rate in immunized grass carp. The results of blood cell counts show that the number of white blood cells in the peripheral blood of immunized grass carp increased significantly from 14 to 28 days post-immunization (dpi). The differential leukocyte count of neutrophils and monocytes were significantly higher than those in the control group at 14 dpi. Additionally, the number of lymphocytes increased significantly and reached a peak at 28 dpi. The serum antibody levels were significantly increased at Day 14 and continued until 42 days post-vaccination. The mRNA expression levels of immune-related genes (IFN-1, TLR22, IL-1β, MHC I, Mx and IgM) were significantly upregulated in liver, spleen, kidney and hindgut after immunization. Four weeks post-immunization, fish were challenged with virulent GCRV by intraperitoneal injection. The results of this challenge study show that orally immunized group exhibited a survival rate of 60% and relative percent survival (RPS) of 56%, whereas the control group had a survival rate of 13% and RPS of 4%. Taken together, our results demonstrate that the silkworm pupae powder containing baculovirus-expressed VP35-VP4 proteins could induce both non-specific and specific immune responses and protect grass carp against GCRV infection, suggesting it could be used as an oral vaccine.


Sign in / Sign up

Export Citation Format

Share Document