Brazilian biologists (cited in Lovshin 1977) investigated the growth
and production of the same all-male hybrid at higher stocking levels over
a 367day culture period in 350-m2 earthen ponds, with no replication
(Table 1). The fish were fed aration of 50% babacu cake and 50% cottonseed
cake at 5% of pond fish biomass/day, 5 days a week. Feeding rates were
recalculated each month based on pond seine samples. Each pond was
fertilized with a total of 19 kg (540 kg/ha) of both TSP and AS applied at
2-week intervals over the first 7 months of the experiment. Productions were
the highest yet obtained in research with hybrid tilapia in Brazil: very
impressive considering that only vegetable materials were fed to the fish.
Increasing the stocking rates had a positive effect on production without
greatly reducing growth. Feed conversion was good up to 6 months, average
at 10 months and poor at 12 months. From the tenth month until harvest,
FCR's increased sharply because of extremely poor water quality and high
standing crops. The maximum feeding rate was 20 kg/pond (564 kg/ha) in
the pond stocked at the rate of 31,000 fish/ha.
Da Silva and Lovshin (cited in Lovshin 1977) tested the culture of the
same all-male hybrid in conjunction with the fattening of pigs in Pentecoste,
Brazil. Three ponds of 1,000-m2 were stocked with 25 g hybrid fingerlings at
the rate of 8,0001ha. One pig sty was constructed on the margin of each
pond and 7 pigs (70/ha of pond water) averaging 17 kg were placed in each
sty. The pigs were not allowed to enter the ponds. The sties were cleaned
daily and all waste products washed into the ponds. The pigs were fed a daily
ration of 5% of their body weight consisting of 35% manioc, 20% wheat
bran, 15% corn, 15% babacu cake, and 20% grass. The ration contained 10%
protein. After 189 days, 1,490 kg/ha of fish were harvested averaging 205 g.
The pigs averaged 60 kg each. The FCR for the pigs was 7.1 and 5.9 for
combined pigs and fish production.
Da Silva et al. (unpublished data) carried out a second experiment to
study the performance of the all-male hybrid with a waste loading equivalent
of 120 pigstha of pond water. Hybrids averaging 29 g were stocked in three
1,000-m2 ponds at the rate of 10,00O/ha and received only the organic
wastes washed daily into the ponds from adjacent pig sties. The pigs were fed
a daily ration of 5% of their body weight consisting of 24% babacu cake,
45% corn, 5% meat meal, 25% elephant grass, and salt. After 180 days, 2,800
kg/ha of fish were harvested averaging 272 g. FCR for the pigs was 7.6 and
5.5 for combined pig and fish production.
Da Silva et al. (cited in Lovshin 1977) carried out a third experiment
with six pigs per sty (60/ha of pond water), fed a daily ration of corn,
babacu cake, meat meal, and ass (i.e. 11.6% total protein) at 5% of their
body weight. Three 1,000-m P ponds were stocked with 10,000 fish/ha
averaging 31 g. The fish were fed cottonseed cake at 2% of their body
weightlday, 6 days a week. Wastes from the pig sties were washed into the
ponds daily. After 193 days, 3,043 kg/ha of fish were harvested averaging
304 g. The FCR for pigs was 6.4 and the FCR for cottonseed cake to fiSh
was 1.7.
Da Silva et al. (cited in Lovshin 1977) stocked three 1,000-m2 ponds
with 25 g hybrid fingerlings at 8,00O/ha. The ponds were fertilized with
50 kg/wk (500 --- kg/ha/wk) --- -- of chicken manure taken from a commercial
sean pound
(Sean Pound)
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