Livestock Research for Rural Development 22 (9) 2010 Notes to Authors LRRD Newsletter

Citation of this paper

Growth of earthworms (Perionyx excavatus) on cattle or buffalo manure with or without water hyacinth

Nguyen Huu Yen Nhi, T R Preston*, Brian Ogle** and Torbjorn Lundh**

An Giang University, 25 Vo Thi Sau St., Long Xuyen City, Vietnam
nhynhi@agu.edu.vn
* TOSOLY, AA 48 Socorro, Colombia.
** Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences,
PO Box 7024, 750 07, Uppsala, Sweden.

Abstract

The growth of earthworms (Perionyx excavates) was studied in a 2*2 factorial experiment with 4 replicates, in which the treatments were: source of manure (cow or buffalo) and supplementation with water hyacinth at 25% of the weight of manure (DM basis) or none.

Adding chopped water hyacinth to buffalo or cattle manure led a decrease in worm numbers and in productivity per kg DM and crude protein of added substrate.  Relative growth in numbers and in weight of the worms was similar on manure derived from buffaloes and cattle. The negative effect of water hyacinth was greater with buffalo than with cattle manure. Residual compost from cattle manure was richer in N and poorer in ash than compost derived from buffalo manure. Water hyacinth added to the substrate resulted in compost with less N but more ash.

Keywords: Ash, chemical composition, compost, earthworms, fermentation, nitrogen, substrate


Introduction

The increase in the population in Vietnam and in the standard of living is creating an increased demand for animal products. However, as livestock production increases so does the environmental pollution through insufficient attention being given to systems of recycling of the excreta.

There are many ways to recycle the organic manure from animals. It can be applied to fish ponds (Prowse 1961), used to feed larvae (Mao Zhang 2004; Latsamy Phounvisouk and Preston 2007), applied to the soil to increase organic matter content (Haynes and Naidu 1998), and especially for raising of earthworms (Hughes et al 1994; Nguyen Quang Suc et al 2000). According to many studies, the earthworms have a diverse role in agriculture. They can be used in breaking down organic wastes (Phan Phuong Loan et al 2009; Edwards and Arancon 2004; Garg et al 2005), to improve the physical structure of the soil, and to enhance soil fertility by providing organic matter, which leads to better crop growth. Earthworms are rich in high quality protein and can be fed to fish (Yaqub 1997; Phan Phuong Loan et al 2009), frogs (Latsamy Phounvisouk and Preston 2007), chickens (Rodríguez et al 1995; Sorn Suheang and Preston 2005; Vu Dinh Ton et al 2009), rabbits (Orozco Almanza et al 1988), ducks and turtles (Bui Xuan Men et al 2007). The many opportunities to use earthworms have created a demand to cultivate them, which creates ways in which farmers in the countryside can raise their income.  Thus, raising earthworms is one of the ways of making better use of local resources which are abundant in the rural areas (Keo Sath 2005).

There are many ways to raise earthworms. Different sources of manures (from pigs, cows, buffaloes, goats, chickens and rabbits) have been used (Nguyen Quang Suc et al 2000; Chu Manh Thang 2003; Garg et al 2005; Nguyen Hieu Phuong 2008). According to Garg et al (2005) earthworms grew best on sheep manure, while worms grew fastest on goat manure in the experiments of Nguyen Quang Suc et al (2000) and Nguyen Hieu Phuong (2008).  Vegetable wastes (Luu Huu Manh et al 2009), maize stover and rice straw (Tian et al 1997) and water spinach and water hyacinth (Kong Saroeun and Khieu Borin 2007) have been mixed with manure for growing earthworms.

Different species of earthworms have been used. The Califorrnia Red worm (Eisenia foetida) has been the subject of most of the studies. However, Perionyx excavates, an earthworm adapted to living in environments with high levels of organic matter (Edward et al 1998), has been used in a recent study, with good results (Phan Phuong Loan et al 2009).

For the above reasons, this experiment was conducted to find out if there were advantages from incorporating vegetative matter with livestock manure as substrate for earthworms.

Hypothesis
 Objective


Materials and methods

Location and climate

The experiment was conducted in the experimental farm of An Giang University, Long Xuyen City, Vietnam. The climate is tropical monsoon, with a rainy season between May and October and a dry season from November to April. The mean air temperature is 27°C and annual rainfall 1400-1500 mm. The duration of the study was 3 months, from September 2009 to December 2009. 

Experimental treatments and design

The treatments were:

The treatments were arranged as a 2*2 factorial with 4 replications in a completely randomized design (CRD) (Table 1). Individual treatments were:

·         C100: Cow manure 100% without water hyacinth

·        C75: Cow manure 75% and water hyacinth 25% (DM basis)

·        B100: Buffalo manure 100% without water hyacinth

·        B75: Buffalo manure 75% and water hyacinth 25% (DM basis)


Table 1. Experimental layout

C100

C75

B100

B100

B75

C75

C100

B75

B75

B100

B75

C100

B100

C100

C75

C75


Experimental feeds

The earthworms (Photo 1) were bought from Cuu Long Delta Rice Research Institute, O Mon District, Can Tho City.


Photo 1. Earthworm (Perionyx excavatus) Photo 2. Water hyacinth (Eichhornia crassipes)

Cow and buffalo manure were bought from farmers around Long Xuyen City. Water hyacinth (Photo 2) was collected from the canals and rivers in Long Xuyen City.  

The earthworms were raised in baskets lined with plastic sheets (Photo 3). The earthworms (100g) were put in the bottom of each basket followed by the manure. Fresh water hyacinth (aerial parts and roots) was chopped and mixed with the manure. At the beginning a total of 500 g DM of substrate was added to each basket. More substrate was added according to the rate at which it was utilized. Weights of fresh manure and water hyacinth that were added were recorded and samples taken for determination of DM, ash, crude fibre (CF) and crude protein (CP). Clean, fresh water was sprayed on the baskets to keep an appropriate moisture level throughout the experiment. 

Measurements
Before putting the earthworms into the baskets, a random sample of 30 worms was taken to determine the average length and weight of individual worms. A sample of the worms was analyzed for DM, CP and ash. After 12 weeks the earthworms were separated from the residual substrate (Photo 4). Both worms and substrate were weighed and samples taken for analysis of DM, CP and ash.  After harvesting the earthworms, the total weight in each basket was determined. A random sample was chosen of 30 worms for determining average length and weight. From the average weight of the earthworms the total number present in each basket was calculated. A sample of worms from each treatment was analyzed for DM, CP and ash.  The residual quantities of residue in each basket were weighed and a sample analyzed for DM, CP, CF and ash.

Photo 3. Feeding the earthworms Photo 4. Harvesting the earthworms

Chemical analysis
Manure, water hyacinth, compost and earthworms were analyzed for DM, CP, CF and ash according to AOAC (1990) procedures.
Statistical analysis

Data were analyzed using the General Linear Model (GLM) option of the ANOVA program in the Minitab software (Minitab release 13.3, 2000). Sources of variation were: Manure source, water hyacinth, interaction manure*water hyacinth and error.

Results and discussion

Composition of substrate for raising earthworms

The moisture and CP contents of water hyacinth were higher than in the buffalo and cattle manure (Table 2) and were similar to the values reported by Chhay Ty et al (2007) and Nguyen Thi Kim Dong and Nguyen Van Thu (2009). Abdelhamid and Gabr (1991) reported that the water hyacinths collected from a canal had 9.5% DM and 74.3% OM, 20% CP and 18.9% CF in the DM.


Table 2. Composition of manure from cattle and buffalo and water hyacinth

 

Buffalo

Cattle

Water hyacinth

DM,%

21.2

16.8

9.16

As % in DM

 

 

 

CP

9.35

10.4

11.6

Ash

35.1

9.50

31.5

CF

15.6

25.4

17.9


Earthworm production

Adding chopped water hyacinth to the manure led to a decrease in worm numbers and in productivity per kg total substrate DM and also per kg of manure DM (Table 3). A similar effect was observed for the utilization of the CP. Thus, incorporating water hyacinth in the manure had a detrimental effect on the efficiency of utilization of the manure by the worms. There was an interaction between the source of manure and addition of water hyacinth (Table 5; Figures 1 and 2). The reduction in earthworm numbers and their growth due to the water hyacinth was greater on buffalo manure than on cow manure.  According to Sherman (2003), fresh organic matter added to earthworm beds will cause an increase in temperature of the beds, due to the fermentation of readily degradable carbohydrate. This could result in the death of some of the worms. This could be the explanation for the reduction in worm numbers when the water hyacinth was added to the manure.


Table 3. Effect of water hyacinth on body length (cm), weight (g) and number of earthworms

 

Manure with water hyacinth

Manure without water hyacinth

SEM

Prob.

Body length, (cm)

Initial

4.21

4.21

 

 

Final

6.50

5.81

0.25

0.07

Length increase

2.29

1.60

0.25

0.07

Earthworm weight, g

Initial weight/ basket

100

100

 

 

Final weight/ basket

136

215

5.16

0.001

Weight gain/kg DM of added substrate

15.6

38.3

1.86

0.001

Weight gain/kg of added manure DM

20.8

38.3

 

 

Weight gain/g CP of added substrate

0.15

0.39

0.02

0.001

Weight gain/g CP from manure

0.20

0.39

 

 

Earthworm number

Initial number/basket

916

916

 

 

Final number/basket

1167

2106

156

0.001

Number increase/kg DM of added substrate

106

389

48.1

0.001

Number increase/g CP of added substrate

1.03

4.00

0.52

0.001



Figure 1. Effect of water hyacinth added to buffalo and cattle manure
on earthworm gain in weight per unit added substrate DM
Figure 2. Effect of water hyacinth added to buffalo and cattle manure
on earthworm gain in weight per unit added substrate CP

The source of manure had no effect on the growth in numbers and in weight of the worms (Table 4). However, the worms grown on cattle manure were longer than those grown on buffalo manure.


Table 4. Effect of  buffalo and cattle manure on the body length (cm), weight (g) and number of earthworms

 

Buffalo manure

Cattle manure

SEM

Prob.

Body length, (cm)

Initial

4.21

4.21

 

 

Final

5.82

6.50

0.09

0.001

Length increase

1.61

2.29

0.25

0.1

Earthworm weight, g

Initial weight/basket

100

100

 

 

Final weight/basket

175

176

15.7

0.98

Weight gain/kg DM of added substrate

24.3

29.6

4.56

0.43

Weight gain/kg fresh of added substrate

3.70

4.53

0.83

0.49

Weight gain/g CP of added substrate

0.26

0.28

0.05

0.71

Earthworm number

Initial number/basket

916

916

 

 

Final number/basket

1827

1447

226

0.25

Number increase/kg DM of added substrate

292

203

70.0

0.38

Number increase/g CP of added substrate

3.10

1.94

0.73

0.28


The relative increase in numbers of worms during the trial varied among the treatments, with the highest number on the B100 treatment (Figure 3). At the end of the trial the weights of individual worms on the different treatments did not differ from the weights at the beginning (Table 6). In contrast, the worms at the end were longer than at the beginning, and thus the ratio of weight to length decreased (Figure 4). This was reflected in a tendency (P=0.069) for a decrease in CP content of the worms at the end compared with the beginning. Surprisingly, there were no changes in OM content. There must therefore have been a change in some other component of the body (other than protein and ash) in the worms at the end compared with those at the beginning.


Table 5. Effect of buffalo and cattle manure, with or without water hyacinth, on the growth and reproduction of earthworms

 

B75

B100

C75

C100

SEM

Prob.

Earthworm weight, g

Initial weight/basket

100

100

100

100

 

 

Final weight/basket

125a

227d

148b

204c

4.07

0.001

Weight gain/kg of added substrate (fresh)

1.22a

6.19c

2.77b

6.30c

0.23

0.001

Weight gain/kg of added substrate (DM)

9.74a

38.9c

21.6b

37.7c

1.49

0.001

Weight gain/g CP of added substrate

0.10a

0.42c

0.20b

0.36c

0.02

0.001

Earthworm number

Initial number/basket

916

916

916

916

 

 

Final number/basket

1176a

2478b

1159a

1735ab

185

0.001

Number increase/kg DM of added substrate

104a

481b

108a

298ab

63.3

0.002

Number increase/g CP of added substrate

1.05a

5.14b

1.01a

2.87ab

0.64

0.001

abc Means within rows without common letter are different at P<0.05
B75, 75% buffalo manure and 25% water hyacinth  (DM basis)
B100,  Buffalo manure only (DM basis)
C75, 75% Cattle manure and 25% water hyacinth  (DM basis)
C100, Cattle manure only (DM basis)

 

Table 6. Effect of buffalo and cattle manure, with or without water hyacinth, on the number, mean weight and composition of earthworms

 

Initial

B75

B100

C75

C100

SEM

Prob.

No./basket

916b

1176b

2478a

1159b

1735ab

222

0.001

Weight, g/worm

 0.109ab

0.106ab

0.094b

0.129a

0.124a

0.008

0.003

Length, mm

42.1c

63.0a

53.4b

67.1a

62.8a

1.50

0.0001

W/L, g/mm

0.259a

0.166b

0.173b

0.189ab

0.191ab

0.014

0.011

DM, %

18.2b

21.0a

20.9a

20.7a

20.5a

0.37

0.02

As % of DM

  CP

75.0

66.5

59.1

67.0

65.2

2.88

0.069

  OM

92.3

93.6

93.7

93.2

93.2

0.41

0.41

abc Means within rows without a common letter are different at P<0.05
B75, 75% buffalo manure and 25% water hyacinth  (DM basis)
B100,  Buffalo manure only (DM basis)
C75, 75% Cattle manure and 25% water hyacinth  (DM basis)
C100, Cattle manure only (DM basis)


Figure 3. Effect of buffalo and cattle manure, with (B75 and C75)
or without water hyacinth, on the number of earthworms per
basket at the end compared with initial values
Figure 4. Effect of buffalo and cattle manure, with (B75 and C75)
or without water hyacinth, on weight/length ratio of the
earthworms at the end compared with initial values

Characteristics of residual “compost”

Addition of water hyacinth reduced the DM, increased the ash, and decreased the CP and the CF contents (Table 7). Buffalo manure resulted in higher DM, higher ash and lower CP and CF than when cattle manure was the substrate. There were interactions between the main treatments (Table 8), with the differences between buffalo and cattle manures being less pronounced when water hyacinth had been added to the worm beds.


Table 7. Mean values (main effects) for composition of residual compost after earthworm culture on  manure from buffalo and cattle, with (25WH)  or without (0WH) water hyacinth

 

25WH

0WH

Prob.

Buffalo

Cattle

Prob.

SEM

DM, %

16.3

21.5

0.001

22.9

14.9

0.001

0.23

As % in DM

 

 

 

 

 

CP

1.97

2.22

0.001

1.69

2.51

0.001

0.029

Ash

37.5

32.8

0.001

46.6

23.7

0.001

0.19

CF

10.1

11.2

0.001

9.22

12.0

0.001

0.12



Table 8. Composition of residual compost after earthworm culture on  manure from buffalo and cattle, with or without water hyacinth

 

B75

B100

C75

C100

SEM

Prob.

DM, %

19.2c

26.6d

13.3a

16.5b

0.32

0.001

As % in DM

 

 

 

 

 

 

N

1.65

1.73

2.30

2.72

0.042

0.001

Ash

46.3 c

47.0 c

28.7 b

18.6 a

0.27

0.001

CF

9.31a

9.14a

10.9b

13.2c

0.17

0.001

abcd Means within rows without a common letter are different at P<0.05


The influence of the treatments on the overall fertilizer value of the residual compost depends mainly on the relative values of the contents of N, ash and organic matter.  Compost from cattle manure was richer in N and poorer in ash (but richer in OM) than compost derived from buffalo manure. Water hyacinth added to the substrate resulted in compost with less N but more ash (and less OM). Evaluation of the fertilizer value of the compost, for example by means of the “biotest” (Boonchan Chantaprasarn and Preston 2004; Tran Thi Bich Ngoc and Preston 2006) is a topic meriting future research.


Conclusions

·        Adding chopped water hyacinth to buffalo and cattle manure led to a decrease in worm numbers and in productivity per kg DM and crude protein of added substrate. 

·        Relative growth in numbers and in weight of the worms was similar on manure derived from buffaloes and cattle.

·        The negative effect of water hyacinth was greater with buffalo than with cattle manure.

·        Residual compost from cattle manure was richer in N and poorer in ash than compost derived from buffalo manure. Water hyacinth added to the substrate resulted in compost with less N but more ash.


Acknowledgements

The senior author would  like to express gratitude to the SIDA- SAREC program, which provided the funds for conducting this experiment - a part of the MSc course through the regional MEKARN project. Thanks also to An Giang University and students who helped to conduct the experiment.


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Received 14 August 2010; Accepted 21 August 2010; Published 1 September 2010

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