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Workshop-seminar "Making better use of local feed resources" SAREC-UAF, January , 2000 |
Manure from rabbits, goats, cattle and buffaloes as substrate for earthworms
Nguyen Quang Suc, Le Thi Thu Ha and Dinh Van Binh
Goat and Rabbit Research Centre, Son tay, Vietnam
Abstract
The faeces from goats, rabbits,
cows and buffaloes were used as substrates for earth worm production. 50 kg fresh manure was inoculated with 0.5
kg earthworms. Fresh manure was added every two days and water every day.
Amounts of earthworms were determined at monthly intervals with final harvest at
the end of 4 months. The rate of reproduction and growth of earthworms was faster
and more efficient when the substrate was manure from goats and rabbits rather than
from buffaloes or cattle. The manure
conversion rate (kg dry matter manure/kg fresh worms) was 15 for goats and 28
for cattle. Rate of growth and reproduction of the worms was slow in the first
two months reaching a maximum at three months and then declining slightly in
the fourth month. Maize plants grown on the fresh manure or the worm casts from
the manure grew faster when the manure or worm casts came from goats or
rabbits; lowest growth rates were with manure from cows. Maize grew at twice the rate on the worm
casts compared with the manure. There was a close correlation (R²=0.999) between
efficiency of worm growth on the manure and the growth rates of maize on the
worm casts from the manure. Results from supplementing scavenging chickens with
up to 60 g/bird/day of fresh earthworms were inconclusive.
Keywords: Earthworms, goats, rabbits, cattle, buffaloes, manure, worm casts, chickens.
Introduction
The traditional chicken production system in the household sector of Vietnam, which is scavenging supplemented with cereal grains, is of low productivity. However, to improve the diet by using balanced poultry feeds, or supplements of protein meals such as soya bean and fish meal is expensive and not cost effective in small scale farms. Earthworms produced by using livestock manure as substrate could be a locally available high-quality protein supplement.
This study compares manure from four animal species as substrate for earthworm production and evaluates the use of the worms as a supplement for scavenging chickens and the worm casts (humus) as a fertilizer.
Materials and methods
Earthworm production
Fresh faeces from buffalos, cows, rabbits and goat were used compared as the substrate for growth of California Red worms. Each treatment was started by placing 50 kg of the respective manure source and 0.5 kg of earthworms on a bed of 1 m². Fresh manure was added every two days and water daily.
The amounts of worms and worm casts (humus) were recorded monthly. After 4 months the total amounts of worms and humus were measured.
Fertilizer value of the humus
Samples of humus and of the fresh manure from all four animal species were put in earthenware pots (5 litre capacity) together with three seeds of maize. After 30 days the maize plants were separated from the soil by washing and allowed to drain in the shade for one hour, after which the root and green biomass portions were weighed separately.
Results and discussion
Earthworm production
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Figure 1: Rate of production of earthworms from different substrates over a 4-month period |
Figure 2: Conversion rate (DM basis) of different animal manures to earthworms |
Rates of earthworm production were higher on manure from goats and rabbits than on manure from cows and buffaloes (Figure 1 and Table 1). Rate of production was slow in the first two months but increased dramatically in month 3 with no further increase in month 4.
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Table 1: Amounts of manure used and earthworms produced, and conversion rates of manure to worms |
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Manure, kg |
Earth |
Conversion, kg/kg |
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Fresh |
DM |
worms, kg |
FM |
DM |
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Goat |
236 |
85 |
5.61 |
40.9 |
14.7 |
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Rabbit |
306 |
108 |
5.38 |
51.8 |
18.2 |
|
Buffalo |
313 |
77.6 |
3.65 |
87 |
21.6 |
|
Cow |
276 |
72.3 |
2.93 |
108 |
28.3 |
|
SE |
10 |
3 |
0.25 |
1.5 |
0.6 |
There were major differences between the manures from the different species in the rate of conversion to earthworms, with lowest values for goats and rabbits and high values for cattle and buffaloes (Figure 2 and Table 2).
Worm casts as fertilizer
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Figure 3: Growth of maize plants in manure or worm casts derived from the manure of four animal species, |
Figure 4: Relationship between growth rates of worms fed manure, and maize plants grown in the worm casts from manure, from goats, rabbits, buffaloes and cows |
The value of the worm casts as a source of nutrients for growth of maize was twice that of the raw manure and, within animal species, the manure and worm casts derived from goats and rabbits were superior to that from buffaloes and cows. There was a close correlation between the efficiency of worm growth on the manure and the rate of growth of maize plants on the worm casts (Figure 4).
Earthworms as supplement for scavenging chicken
In the traditional scavenging system it is usual to provide either broken rice or paddy rice as a supplement to scavenging chickens as it is assumed that the feed resources obtained by scavenging will be rich in protein (eg: insects, shoots of weeds, larvae). The following experiment aimed to test the value of small quantities of earthworms as a protein source for scavenging chicken that also received broken rice grains.
Materials and methods
The experiment was done in the Experimental farm of the GRRC.
Eighty local chickens at 40 days of age were purchased from farmers and allocated to 4 treatments:
- Control: Fed with broken rice (50 g/day/head) and scavenging.
- EW20: Same as control but with earth worms at 20 g/day/head.
- EW40: Same as control but with earth worms at 40 g/day/head.
- EW60: Same as control but with earth worms at 60 g/day/head.
The chickens scavenged in the same area during the day and were separated at night time when they received the supplements according to treatment. The birds were identified by number tags on the wing to facilitate individual weighing done at the beginning and every 10 days for a 3 month period. The offered and refused feeds were recorded daily for each treatments.
Results and discussion
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Table 5. Growth rate of scavenging chickens supplemented with broken rice and earth worms |
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Control |
EW20 |
EW40 |
EW60 |
Prob. |
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Liveweight, g |
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Initial |
306±81 |
306±5.68 |
294.0±8.22 |
312.0±9.8 |
0.461 |
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Final |
1348±24.1 |
1353±17.2 |
1678±41.8 |
1414±30.9 |
0.001 |
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Daily gain |
11.6±0.27 |
11.7±0.15 |
15.4±0.42 |
12.3±0.32 |
0.001 |
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The growth rate of the group of chickens supplemented with 40 g/day of earthworms appeared to be higher than for the control or the groups fed 20 and 60 g/day of earthworms. However, this result should be treated with caution, since treatments were confounded with pen location and there was no replication of the treatment pens.
Conclusion
- The rate of reproduction and growth of earthworms was faster and more efficient when the substrate was manure from goats and rabbits rather than from buffaloes or cattle.
- The manure conversion rate (kg dry matter manure/kg fresh worms) was 15 for goats and 28 for cattle.
- The optimum growth cycle appeared to be 4 months from inoculation of the manure (0.5 kg worms to 100 kg manure) to the point of harvest, assuming fresh manure is applied each day.
- Maize plants grown on the fresh manure or the worm casts from the manure grew faster when the manure or worm casts came from goats or rabbits; lowest growth rates were with manure from cows.
- Maize grew at twice the rate on the worm casts compared with the manure.
- There was a close correlation (R²=0.999) between efficiency of worm growth on the manure and the growth rates of maize on the worm casts from the manure.
- Results from supplementing scavenging chickens with up to 60 g/bird/day of fresh earthworms were inconclusive.