Tài liệu Advances in Shrimp Nutrition pptx

Advances in Shrimp Nutrition
Stephen G. Newman Ph.D.
President
Aqua-In-Tech Inc.

Introduction

Basic Nutritional Requirements

Feed additives
–
Glucans
–
Bacterial Cell Wall
–
Nucleotides
–
Fucoidan
–
Others

Conclusion

Basic Nutritional Requirements
Protein levels are species and rearing environment
dependent

P. monodon, P. stylirostrus higher protein

P. vannamei-lower protein-plant derived OK

Similar Vitamin and Mineral Requirements

Closed versus open system culture.

Most ponds provide nutrients to smaller shrimp

Beta 1,3 1,6 glucans

Structure very important for activity

Continuous feeding unwise practice

Non-specific immunity
–
Short term
–
Weakened by stress and high levels of
pathogens

Saccharomyces cereviseae

Glucan Structure

Glucan testing
Harbor Branch Oceanographic Institute
3 levels incorporated into feed
Post larval P. vannamei
Fed for several weeks prior to exposure to WSSV
bacterial suspension
Mortalities followed for 7-10 days and tabulated

Glucan Effective Against WSSV

Bacterial Cell Walls
From both common groups of bacteria
Gram Positive-Peptidoglycan
Gram Negative-Lipopolysaccharide

Peptidoglycan

Peptidoglycan
Itami et al. 1998
P. japonicus fed 0.2 mg of PG per kg/bw/day
95 days
1. 7 days on and 7 off
2. Daily
3. 2 days on and five off
N=20
Continuous water borne challenge

Peptidoglycan

Lipopolysaccharide

Lipopolysaccharide

Lipopolysaccharide
Itami et al. Late 1980’s Kuruma prawns
8 to 11 adults (20 grams each)
1% suspension of dead bacterial material

1-immersion for one hour
2-Sprayed for 10 secs
3-Injected
30 days later injected with virulent strain of vibrio
Statistically significant protective effect

Lipopolysaccharide
Comparative survival of kuruma prawns exposed to virulent
vibrio species 30 days post exposure to a dead vibrio suspension
(after Itami et al.)

Nucleotides
Basic building blocks of DNA and RNA
Needed for all metabolic function
Present in food
External source of bases and precursors is
beneficial
Study feeding PLs at different levels done in Isreal
with P. vannamei

Nucleotides
Stimulates Intestinal flora
Increases number of immunocompetent cells
Increases antibody titers
Modulates glandular activity
No residues
Potentiates activity of antibiotics, vaccines and
other compounds

Nucleotides

Fucoidan

Fucoidan

Fucoidan
Sulfated polysaccharides with high affinity
enveloped viruses
Deeply embedded in algal cell walls
Activity against HIV, Herpes viruses and
WSSV

Fucoidan
Takashi et al. 1998
Fed two dosages 60 and 100 mg/kg/bw/day
Fed for 15 days
Waterborne Challenge
Substantial Protective benefit
Determined to be due to the sulfate group
Used a 70% pure product-$1300/kg
Cruder products may be effective as well

Fucoidan
Fucoidan
0
80
82
0
20
40

60
80
100
1 2 Control
Percent Survival

Others
Wide variety of compounds being examined
with possible beneficial effects including
Levamisole, mushroom extracts such as
VitaStim, lactoferrins, various herbal extracts,
MOS, etc.
Most IMPORTANT
HUSBANDRY, SPF animals to start with,
Good water quality management