Although aquaculture is always referred to as the future solution to feed the nine billion people estimated in world population by 2050, there are still many complications to overcome.

1. A
lthough aquaculture is always
referred to as the future solution
to feed the nine billion people
estimated in world population by
2050, there are still many complications to
overcome.
Shrimp production plays a key role
in aquaculture. Diseases such as Acute
Hepatopancreatic Necrosis Syndrome
(AHPNS) and related outbreaks recently
reported in India, together with raw mate-
rial prices volatility are two major problems
that need prompt solutions if we do not
want to succumb achieving the sustainability
challenge.
Despite this, the outlook is positive.
Although China, Mexico and Thailand are
reporting lower productions than forecasted
for 2014, the volume traded during the first
half of the last year in the international shrimp
market increased by five to six percent com-
pared with the same time period in 2013. In
terms of farmed shrimp production, positive
trends have been posted so far in Ecuador,
Indonesia, Vietnam and India.
Forecast in India
The official forecast in India suggests that
farmed shrimp production, dominated by
Vannamei, may increase by 10 to 20 per-
cent during the current fiscal year (April
2014-March 2015), and Brazil farmed shrimp
production is expected to grow 18 percent
(Intrafish, and FAO Globefish).
Pathologies are going to be present
throughout this year and fish meal/oil prices
are not going to help to create an idyllic
scenario; in early December 2014, IMARPE
confirmed its recommendation after a second
survey that there should be no quota issued
for the second fishing season.
Antibiotics growth promoters, AGP’s are
under surveillance because of suspicions they
create resistance to pathologic bacteria creat-
ing “superbugs” causing 25,000 deaths per
year in Europe, 38,000 deaths in Thailand
and 23,000 deaths per year in the EEUU. The
overall impact cost is estimated to be US$
35 billion in the EEUU (sources: ECDC 2007,
Pumart et al 2012, US CDC 2013)
To overcome all these challenges, a
new generation of additives is being thor-
oughly studied: the natural growth promot-
ers (NGPs). Also termed non-antibiotic
growth promoters, NGPs are feed addi-
tives contemplating different categories as
salts of organic acids, probiotics, prebiotics,
phytogenic or yeast. In addition to the ben-
eficial effects in terms of health status and
performance, NGPs supplementation does
not usually bear any risk regarding bacte-
rial resistance or undesired residues in the
edible fish product.
Several publications have addressed the
effects of short chain fatty acids (SCFA) and
their salts on the health and performance of
fish. These SCFA are commonly known by
their specific antimicrobial activity. However
the effects of SCFA go beyond modification
of gut microflora. Other benefits such as:
improved digestive enzyme activity, increased
pancreatic secretion, enhanced development of
intestinal epithelium and intestinal barrier integ-
rity, or anti-inflammatory properties (Gálfi and
Bokori 1990; Le Gall et al. 2009), have been
described and attributed to likely causes of
Alternatives to achieve the sustainability challenge
in shrimp production:
by Alvaro Ortiz, Aquaculture Product Manager, Norel SA, Spain
Table 1: Minimum Inhibitory Concentration (MIC) for each pathogen
Pathogen Species Butiric Propionic Valerianic
V. anguillarum Salmonids 22.2 mM 33.3 mM 33.3 mM
V. vulnificus Shrimp 22.2 mM 33.3 mM 33.3 mM
V. harveyi Shrimp 22.2 mM 22.2 mM 33.3 mM
V. parahaemolyticus Shrimp 22.2 mM 22.2 mM 33.3 mM
V. alginolyticus Shrimp 22.2 mM 22.2 mM 33.3 mM
A. hydrophila Tropical 22.2 mM 33.3 mM 33.3 mM
A. caviae Tropical 22.2 mM 33.3 mM 33.3 mM
A. salmonicida Salmonids 22.2 mM 22.2 mM 33.3 mM
F. columnare Tropical 22.2 mM 22.2 mM 33.3 mM
Y. ruckeri Salmonids 33.3 mM 33.3 mM 50 mM
Sodium Butyrate
12 | INTERNATIONAL AQUAFEED | May-June 2015
FEATURE

2. enhanced performance, particularly when sup-
plementing butyric acid in its sodium salt form.
Butyric acid is naturally produced and
present within the intestine of both car-
nivores and herbivores fish (Holben et al.
2002; Mountfort 2002). It is very well known
how the anti-inflammatory effect of butyric
acid can prevent the presence of enteritis in
salmon when part of the dietary fishmeal is
substituted by soybean meal. This additive
could therefore be useful to help reducing the
diet costs when fishmeal prices or availability
become unpractical, facilitating a higher inclu-
sion of vegetable raw materials, by means of
increasing their digestibility and counteracting
anti-nutritional effects.
Regarding its pathogen inhibition capabili-
ties, in a recent study conducted by Katsetsart
University (Thailand) and Norel S.A. different
compounds were tested to assess its inhibi-
tion and bactericidal activity against marine
shrimp pathogenic bacteria.
Gustor Aqua (Sodium Butyrate) was test-
ed in this study against V. parahaemolyticus.
A strong inhibitory effect was found for
Gustor Aqua both at pH=5 and pH=6 against
V. parahaemolyticus, microorganism suspect
of causing AHPNS.
In another study
In another study, butyric acid was com-
pared against the most common SCFA exhib-
iting a greater inhibition capacity (University
of Santiago and Norel SA), less quantity of
butyric was needed to inhibit the same con-
centration of pathogens.
Knowing that sodium butyrate might be
of great help in the important shrimp farming
industry, Norel wanted to test the additive
on-the-field and a trial was conducted in a
commercial shrimp farm in Honduras.
Gustor Aqua (protected sodium butyrate)
was tested to determine the effect of the
additive in performance parameters. The ini-
tial density was around 31 shrimp/m2. Ponds
supplemented with Gustor Aqua completed
the fattening period with 35 percent more
biomass, the final yield (kg/ha) in those ponds
was 26 percent higher. Feed conversion ratio
was also influenced by adding the additive,
being 2,033 in the control ponds and 1,590
in the sodium butyrate supplemented group.
Gustor Aqua positively influenced animals’
performance and in addition, their health
status is boosted as the higher survival rate
reflects. The combination of both variables
yields better economic results.
www.norel.es
May-June 2015 | INTERNATIONAL AQUAFEED | 13
FEATURE
Gustor Aqua®
A powerful non-medicated growth promoter
T. +34 91 501 40 41 · info@norel.net · www.norel.net
• Immunological properties:
Anti-inflammatory
Reinforce of the intestinal defence barrier
• Improves performance
• Antimicrobial activity
• Trophic effect on intestinal epithelium
Providingproficienttoolstoachievecost-effectiveandsustainableaquaculturepractices