Carp is one of the main species of China's aquaculture industry, forming 13 percent of its farmed fish output. Because of their wide adaptability, carp can be farmed in an extensive variety of regions. However, in recent years their quality in China has declined. With the blind pursuit of production volumes and backward steps in breeding management technology, many problems have appeared in carp aquaculture.
2. EXPERT T●PIC
EXPERT TOPIC
CARP
Welcome to Expert Topic. Each issue will take an in-depth look
at a particular species and how its feed is managed.
42 | INterNatIoNal AquAFeed | November-December 2013
3. EXPERT T●PIC
3
1
2
is deglutition. Carp fry mainly eat zooplankton,
and later begin to eat benthos. When their
body length reaches 7-17 cm, under natural
conditions carp eat crustaceans, insect larvae,
algae, plant tissue and so on. In the aquaculture industry farmers use compound feeds to
provide their nutrition.
1
China
Overview of the
present situation of
carp farming in China
Distribution
by Wang Xin, Song Zhigang, Yang
Yong, Guangzhou Hinter Biotechnology,
Guangdong, China
C
arp is one of the main species
of China's aquaculture industry,
forming 13 percent of its farmed
fish output. Because of their wide
adaptability, carp can be farmed in an extensive
variety of regions. However, in recent years their
quality in China has declined. With the blind
pursuit of production volumes and backward
steps in breeding management technology, many
problems have appeared in carp aquaculture.
Biological characteristics
Common carp belongs to the taxonomic
group Osteichthyes of the animal kingdom,
in the Cyprinidae family of the Cypriniformes
subclass. Carp live at the bottom of water
bodies, and tend to stir them up in foraging
activity. Common carp can quickly adapt to
the temperature and quality of water, and
grow quickly at the same time (1 kg or more
in a single year). Their breeding season is early
April to early June, and reach sexual maturity
after two years.
Carp is a typically omnivorous fish, although
they can be carnivorous. Their feeding mode
Common carp grow quickly, have high
output and a strong tolerance for environmental conditions, which means they
can be cultivated widely from the northern provinces Heilongjiang, Liaoning,
Tianjin, Hebei and Shanxi, to the southern
provinces Yunnan, Sichuan and Guizhou.
As mentioned above, carp is one of the
main species for Chinese aquaculture,
making up 13 percent of total production
volume.
Common species
The most common carp species in China
are Jian carp, Yellow River carp, red carp
and German mirror carp. All have similar
nutritional requirements although fish farmers
must bear certain differences in mind. German
mirror carp typically exhibit higher feed conversation ratios than the Yellow River or Jian
varities, and consequently tend to enjoy a
faster growth rate (reaching 1.25 kg after a
year, rather than 1 kg).
However, the disease resistance of German
mirror carp is poor, and require higher
water quality to be successfully farmed. For
these reasons, all three are viable aquaculture species, although German mirror carp
enjoy higher and more stable prices in the
marketplace.
2
USA
Aquaculture carp threat
to Great Lakes wildlife
T
hough a popular species for farming in
their own right, carp’s bottom-dwelling
behaviour, tolerance of a wide range of
environmental conditions and omnivorous feeding habits also makes them an attractive
candidate for integrated aquaculture systems.
Authorities in the Great Lakes region of the
United States are now having to deal with the
drawbacks of this hardiness, as Asian carp species originally imported to the southern states
to control vegetation in aquaculture and wastewater treatment have been found spawning as
far north as the Sandusky River in Ohio.
It is a well-established fact that the Mississippi
River is infested with Asian carp, and one of those
species, the grass carp, has made the jump to the
tributary river of Lake Erie. Although vegetationeating grass carp do significant damage to aquatic
habitats, scientists are particularly worried about
the prospect of bighead carp and silver carp joining
them. They require similar spawning conditions to
the species already in place, but as plankton feeders
will out-compete and out-breed native fish.
US environmental official John Goss has called
for the renewal of the administration’s US$200 million “aggressive strategy” to keep the Great Lakes
free of the invasive species. Given the threat to the
US$7 billion sports fishing industry and US$234
million commercial fishery in both the USA and
Canada, it’s time to cut the carp.
November-December 2013 | INterNatIoNal AquAFeed | 43
4. EXPERT T●PIC
3
Optimum
protein
and lipid
balance for
C. auratus
by Patrick Haughton, Hampshire Carp
Hatcheries, UK
T
he growing season for first year
cyprinids is short in the UK.
Typically the fish are spawned in
late April and May and the fry
are stocked out into ongrowing ponds in
late May to early June. For the first two
or three weeks their diet is predominantly
zooplankton before they are weaned onto a
commercial dry diet.
The fish farmer then has 16 weeks of
temperatures above 15 °C (average 20 °C)
to grow the stock to a market size of 5 to 50
g (5-14 cm) for the following spring's market mercial diets in triplicate so that their comdemand. It is vitally important to maximise mercial performance could be measured.
The key parameters that were measured
weight gain over this period. Protein efficiency
ratios (PER) are less important as the ponds were growth, feed utilisation, economic perhave a high capacity to process ammonia, with formance and condition factor (shape).
the long day lengths resulting in dense algae
blooms and supersaturation of oxygen.
Experimental materials
Most of the diets available to the freshwa- and procedure
ter fish farmer in the UK are sold as optimal
The trial was conducted in twelve aquarifor carp or trout. By using a range of protein ums (dimensions 90 x 30 x 30 cm) in a
and lipid combinations, this trial intended to recirculation unit. Each aquarium maintained a
extend the understanding of the
optimum balance for the intensive
table 1:
ongrowing of first year goldfish.
Price
Protien %
lipid %
In collaboration with Coppens
euro/kg
International, Hampshire Carp
Hatcheries carried out an eightStandard (S)
33%
6%
0.95
week feed trial on goldfish (C.
Basic select (BS)
34%
15%
1
auratus) at Sparsholt College's
Supreme 16 (S16)
46%
16%
1.19
National Aquatics Training Centre.
The goldfish were fed four comPrime 18 (P18)
42%
18%
1.13
table 2:
Gross
energy
(MJ/kg)
Standard (S)
Metabolisable
energy (MJ/
kg)
relative
metabolisable
eneergy
relative
feed rate
Daily feed
rate
18.09
14.12
82.0%
1.22
3.66%
Basic select (BS)
20.26
16.57
96.2%
1.04
3.12%
Supreme 16 (S16)
21.14
17.01
98.7%
1.01
3.04%
Prime 18 (P18)
21.37
17.23
100%
1.00
3%
44 | INterNatIoNal AquAFeed | November-December 2013
5. EXPERT T●PIC
flow of one litre per minute
table 3:
at 20 °C.
Diet
Each morning the
aquariums were cleaned by
siphoning any suspended
Standard
solids and faeces. Water
Basic select
was replenished from a resSupreme 16
ervoir of standing dechlorinated water. Ammonia
Prime 18
levels were routinely monitored throughout the trial.
Prior to the start of
the trial, the goldfish were
acclimatised to the aquariums for two weeks whilst
being fed on a maintenance ration. At the start
of the trial each aquarium
was randomly stocked
with 20 15 g (±0.5 g)
goldfish. The mean values
of the bulk weights of the fish on each diet
were tested for differences using a one-way
analysis of variance. There was no significant difference in bulk weights (p>0.05,f =
0.56,d.f.3,8).
The fish receiving the most energy-rich
diet, Prime 18, were fed at 3 percent body
weight a day. The other diets were fed isocalorifically, so that all fish in the trial would
have the same energy available (see Table 2).
The daily ration for each tank was pre-
Protein,
lipid%
Foof fed (gr)
FCr
Per
% Weight gain
SGr %
33 & 6
744 (+/=56)
2.47 (+/-0.12)
1.23 (+/-0.06)
100%(+/-4.4)
1.24% (+/-0.04)
34&15
662 (+/-58)
1.95 (+/-0.13)
1.21 (+/-0.09)
113%(+/-7)
1.41% (+/-0.06)
46&16
650 (+/-13)
1.8 (+/-0.13)
1.21 (+/-0.07)
121%(+/-11.8)
1.41% (+/-0.09)
42&18
650 (+/-74)
1.72 (+/-0.09
1.39 (+/-0.07)
126%(+/-10.2)
1.46% (+/-0.08)
weighed and divided into two roughly equal
feeds, which were given at 8.30 a.m. and
4.30 p.m. The fish were fed just six days each
week. On the seventh day the fish were bulk
weighed and counted. New rations were
calculated each week based on the new bulk
weights.
At the start of the trial a random sample of
20 fish were weighed and measured for total
length to calculate their condition factor. At
the end of the trial a random sample of 20 fish
from each diet were weighed and measured
for total length.
Results: diet utilisation
and growth
During the course of the trial all of the
feed was observed to be eaten. There were
no mortalities and the water parameters were
recorded the same for all aquariums.
The tanks ate between 650 g and 744 g
of food over the trial. Feed conversion ratios
November-December 2013 | INterNatIoNal AquAFeed | 45
6. EXPERT T●PIC
(FCRs) varied from 1.72 to 2.47, PERs varied
from 1.21 to 1.51, percentage weight gains varied from 100 % to 126 % and specific growth
rates (SGRs) varied from 1.24 % to 1.46 %.
There were highly significant differences
in the diets’ FCRs (p>0.001,f = 203,d.f.3,8).
P18 had a very highly significantly lower FCR
than the S diet (p<0.001). Basic Select (BS)
and Supreme 16 (S16) had a highly significantly lower FCR than the Standard (S) diet
(p<0.01). P18 had a highly significantly lower
FCR than BS (p<0.01). S16 had a significantly
lower FCR than BS (p<0.05).
Very highly significant differences were
found in the PERs of the diets (p>0.001,f
=85,d.f.3,8). BS had a highly significantly greater
PER than S and S16 (p<0.01). BS had a significantly greater PER than P18 (p<0.05). P18 had
a highly significantly greater PER than S and S16
(p<0.01).
The diets’ SGRs also displayed very
highly significant differences (p>0.001,f
=31.5,d.f.3,8). S16 and P18 had a highly
significantly higher SGR than diet S (p<0.05).
BS had a significantly higher SGR than diet S
(p<0.05). P18 had a significantly higher SGR
than diet BS (p<0.05).
table 4:
The daily gross margin per diet varied from
0.174 per day for diet S to 0.209 for diet P18.
The relative economic advantage of BS,
S16 and P18 to diet S were 11 percent, 16
percent and 20 percent respectively.
Carcass analysis
There was no significant difference between
the diets’ condition factors at the start or at the
end of the trial (p>0.05,f=0.43, d.f.4,95).
Conclusion
Over the eight-week trial the fish grew
on average by 115 percent. The Prime 18
diet with 42 percent protein and 18 percent
lipids significantly outperformed the other
diets in growth, FCR and economic efficiency.
However, the Basic Select diet had a significantly better PER than all the other diets. This
has implications for the production in a pond
culture unit where there is a finite nitrification
capacity.
There was no evidence of the extra
growth generated by the high-lipid diets caus-
Cumulative
FCr
Cost of
food (£)/
kg prod.
Gross
margin
(£)/kg
Final
SGr%
Gross
margin*
daily output
relative
advantage
%
Standard
0.81
2.47
2.00
14.00
1.24%
0.174
0%
Basic select
Economics
Food
price
£/kg
0.85
1.95
1.66
14.34
1.35%
0.194
11%
Supreme 16
1
1.80
1.80
14.20
1.41%
0.201
16%
0.96
1.72
1.65
14.35
1.46%
0.209
20%
Prime 18
ing a change to the shape (condition factors)
of the fish.
Further research for goldfish ongrowing could interpolate the optimum protein
between 34 percent and 42 percent, and
extrapolate the optimum lipid above 18
percent where growth is the predominant
requirement.
In the UK during the autumn, winter and
spring months when temperatures are below
15 °C there is negligible growth. Fish are fed
a maintenance ration and it is important to
utilize the protein as efficiently as possible,
and minimize ammonia loading and its associated stock management problems. Further
research is needed to understand more fully
the optimum protein and lipid levels during
this period.
The author would like to thank Coppens
International for their collaboration on this
research.
See all of our EXPERT TOPIC features in
the International Aquafeed archive
About the author
During his 30-year lectureship in the
fisheries department at Sparsholt
College, UK, Pat Haughton has carried
out nutritional trials for feed companies and student dissertations.
He has retired as a lecturer but
runs Hampshire Carp Hatcheries in
partnership with Chris Seagrave. The
hatchery is the UK's largest cyprinid
fingerling producer, rearing eight species of cyprinids (chub, barbel, ide,
tench, carp, goldfish, gudgeon and
stickleback), and 20 colour varieties of
these species. Their website is regularly updated to feature the farming
operations and all areas of research
and development.
www.aquafeed.co.uk
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