Dissertation > Excellent graduate degree dissertation topics show

Effects of Several Immunostimulants on the Growth Performance, Non-specific Immunity and Disease Resistance of Cobia, (Rachycentron Canadum)

Author: GengXu
Tutor: DongXiaoHui
School: Guangdong Ocean University
Course: Aquaculture
Keywords: Rachycentron canadum Immunostimulant Probiotic Immunity Growth Challenge
CLC: S963
Type: Master's thesis
Year: 2011
Downloads: 18
Quote: 0
Read: Download Dissertation

Abstract


The present study was performed to investigate the effects of dietary on the growth performance, non-specific immunity and protection against Vibrio harveyi infection in cobia, Rachycentron canadum. The results can be summarized as follows:1. The aim of this study was to examine the effect of the compound immunostimulants containingβ-glucan, A3a-peptidoglycan, vitamin C and vitamin E (China Patent No. ZL03112114.4.) on the growth performance, non-specific immunity and protection against Vibrio harveyi infection in cobia (Rachycentron canadum). Fish were fed diets containing six graded levels of compound immunostimulants (0, 1, 2, 3, 4 and 5 g kg-1 diet) for 8 weeks. The results showed that the survival rate ranged from 81.1% to 84.4% with no significant difference among all the groups (P > 0.05) after feeding experiment. Dietary compound immunostimulants significantly increased the specific growth rate (SGR), serum lysozyme, alternative complement pathway (ACP) activity, phagocytosis percentage (PP), respiratory burst activity of head kidney macrophages of cobia. Moreover, feeding of supplemented diets containing 3.0 g kg-1 compound immunostimulants resulted in significantly lower mortality against the pathogens, Vibrio harveyi compared with the control group. To elevate the growth and immune resistance ability of cobia, the optimal dose of dietary compound immunostimulants administration, determined by second-order polynomial regression analysis were 3.43 and 2.71 g kg-1 diet respectively, on the basis of the SGR and mortality after challenge with V. harveyi.2. A feeding experiment was conducted to investigate the compound probiotics containing Bacillus subtilis 7.0×109 CFU g-1, Bacillus licheniformis 3.0×109 CFU g-1, Lactobacillus spp. 5.0×108 CFU g-1 and Arthrobacter spp. 1.0×108 CFU g-1 on the growth performance, non-specific immunity and protection against Vibrio harveyi infection in cobia (Rachycentron canadum). Fish were fed diets containing six graded levels of compound probiotics (0.0 g kg-1, 1.0 g kg-1, 2.0 g kg-1, 3.0 g kg-1, 4.0 g kg-1 and 5.0 g kg-1) for 8 weeks. The results showed that the survival rate ranged from 81.1% to 84.4% with no significant difference among dietary treatments (P > 0.05) after feeding experiment. Dietary compound probiotics significantly increased the specific growth rate (SGR), serum lysozyme, alternative complement pathway (ACP) activity, phagocytosis percentage (PP), respiratory burst activity of head kidney macrophages of cobia. Moreover, feeding of supplemented diets containing compound probiotics resulted in significantly lower mortality against the pathogens, Vibrio harveyi compared with the control group. To elevate the growth and immune resistance ability of cobia, an optimal dose of dietary compound probiotics administration, determined by second-order polynomial regression analysis was 3.3 g kg-1, on the basis of the SGR and mortality after challenge with V. harveyi.3. The present study was performed to investigate the effects of various levels of dietary Bacillus subtilis and chitosan on the growth performance, non-specific immunity and protection against Vibrio harveyi infection in cobia, Rachycentron canadum. Fish were fed with the control diet and six different experimental diets containing three graded levels of B. subtilis @ 2×1010 CFU g-1 (0.0, 1.0, 2.0 g kg-1 diet) for each of two levels of chitosan (3.0 and 6.0 g kg-1 diet). The results of 8 weeks feeding trial showed that the survival rate ranged from 81.3% to 84.0% with no significant difference among all the groups (P > 0.05). The SGR (%) in the fish fed with dietary treatments was significantly higher than that of the control fish except diet group with 2.0 g kg-1 B. subtilis and 3.0 g kg-1 chitosan; significant maximum SGR was observed in the fish fed with 1.0 g kg-1 B. subtilis and 6.0 g kg-1chitosan. The serum lysozyme activities were significantly higher in 6.0 g kg-1 chitosan groups than that in 3.0 g kg-1 chitosan groups and the control group; no significant differences were observed among B. subtilis levels, at the same chitosan supplemental level. The serum ACP activities were significantly higher in 3.0 g kg-1 chitosan groups at 0.0 and 1.0 g kg-1 B. subtilis levels; at low chitosan level, the cobia fed diets with 1.0 g kg-1 B. subtilis had significantly higher serum ACP activity, but at high chitosan level, the cobia fed diets with 2.0 g kg-1 B. subtilis had significantly higher serum ACP activity. In the groups with 2.0 g kg-1 B. subtilis regardless of chitosan levels, the phagocytosis was significantly increased, but the respiratory burst activity was significantly decreased compared with 1.0 g kg-1 B. subtilis. At any of three B. subtilis level, the groups with 3.0 g kg-1 chitosan had higher the phagocytosis and respiratory burst activity, but at 2.0 g kg-1 B. subtilis level, the groups with 6.0 g kg-1 chitosan had higher respiratory burst activity. Moreover, fish fed the diet containing 2.0 g kg-1 B. subtilis and 6.0 g kg-1chitosan had significantly higher post-challenge survival on the 7th day following Vibrio harveyi infection and post-challenge survival showed clearly the synergistic effect of chitosan and B. subtilis. Based on these results, the combination of 1.0 g kg-1 B. subtilis and 6.0 g kg-1 chitosan is optimal for the growth, innate immunity and disease resistance of cobia with an 8-week oral administration and dietary B. subtilis and chitosan should be taken into account when a long term oral administration is conducted.

Related Dissertations

  1. Expression Survey of Key Factors of Canonical Wnt Signalling Pathway in the Human Embryonic Tooth Germ,R78
  2. Growth Pattern of Marsupenaeus Japonicus and Succesion of Plankton Community in Intensive Model,S968.22
  3. Cloning and Expression of Growth Hormone Gene in Cobia (Rachycentron Canadus),Q786
  4. Screening of Plant Pathogen Inhibition of Plant Extracts,S482.2
  5. Growth Rate and Growth Model of the F5 Selected Lines for Four Shell Colors of Pinctada Martensii (Dunker) Cultured in Deepwater Area of Beibu Bay in Zhanjiang and Their Genetic Diversity Analysis Using SSR Molecular Markers,S968.31
  6. Effects of the Nitrogen Management and Interactions with Leaf Number on Growth Yield and Quality of Burley Tobacco,S572
  7. Effects of Temperature and Raising Seedling Pattern on the Growth and Development of Strawberry,S668.4
  8. Effect of High Level of Copper and Zinc on Growth Performance and Metabolism and Its Content Level in Serum and Deposit in Tissues of Weanling Piglet,S828.5
  9. Effects of Low-protein Diet on Production Performance and Feeding Environment of Piglet,S828.5
  10. Comparative Analysis of Growth, Digestive Enzyme Activities and Pearl-SAC Development Between Two Different Sized Pinctada Martensii during Pearl Culturing,S917.4
  11. Study on Microorganism Contamination Control and Decontamination of Chilled Carved Pork,R446.5
  12. Identification of B.melitensis 16M Protein Immunodominant Antigens,S852.61
  13. The Effect of Fertilizer Application on Yield and Quality in Chrysanthemum Morifolium,S567.239
  14. Preliminary Study on Obstacles Effect of Succession Cropping and Reduction Techniques of Microbial Agents in Flue-cured Tobacco,S572
  15. Effects of Different Fertilizer Combinations on Flue-cured Tobacco Growth, Quality and Soil Nutrient,S572
  16. Studies on Key Planting Skills of Cigar-Wrapper Tabacco,S572
  17. Studies on the Life Cycle and Classification of Agrocybe Salicacola,S646
  18. Study on the Trophic Value of Blood Meal by Different Processes and the Effects of Supplements in Broiler Chicken,S831.5
  19. The Research of Microsatellite Markers and the Eatablishment of Growth and Development Model in Xianan Cattle and Pinan Cattle,S823
  20. Study on the Separation and Purification Way of Arctiin from Fructus Arctii and the Effect of Arctiin on the Growth of Mice C2C12 Cells,S853.7
  21. Applied Research of Hemicell? Feed Additive in Weaned Piglets,S828.9

CLC: > Agricultural Sciences > Aquaculture, fisheries > Aquaculture technology > Aquatic animal feed nutrition
© 2012 www.DissertationTopic.Net  Mobile