Four sources of substrate (solid cattle manure, cattle manure in suspension, and pig and goat manure in suspension) were arranged in a randomized complete block design (RCBD) to evaluate the biomass yield and reproduction of earthworms (Eisenia foetida). The earthworms were incubated in plastic baskets lined with banana leaves.

The suspension of goat manure increased markedly the final weight of worm biomass, and improved the DM conversion rate compared with the other substrates. Crude protein conversion rate did not differ between substrates of goat and cattle manure but was inferior on the pig manure. Final numbers of worms were greatest on the goat manure. There were no differences between application of the cattle manure in solid form or as a suspension. There were indications that there were more cocoons in the baskets with suspended cattle and goat manure than in those with solid cattle manure and pig manure Composition of the worms and the residual compost did not differ among the substrates. It is suggested that the poor growth of earthworms on the pig manure may be because this substrate is not a good medium for microbial activity.

Keywords: Baby worms, biomass, California red worm, cocoons, compost, Eisenia foetida, growth rate

Introduction

With the development of economics and technology, the human race faces many environmental problems caused by pollution and accumulation of organic waste from live stock production. Moreover, increasing the intensification of live stock production due to the need to increase food production is damaging the environment because live stock excreta are frequently a source of environmental pollution in intensive specialized animal agriculture (Nguyen Duy Quynh Tram 2004). This is the reason why not only is there a need to improve food quantity but also to protect the habitat around us.

According to many studies and practices, one of the major players in waste management is the earthworm. For a long time, their special roles have been forgotten. For example, worms themselves can be fed to chickens as a high quality protein supplement and they can increase the growth rate and feed conversion of fish (Nguyen Duy Quynh Tram et al 2004). Worm casts are a form of natural fertilizer as they are rich in nutrients (Nguyen Hoang Minh Tu 2008). They also improve the quality of soil by providing organic matter, which enhances crop growth. From these different benefits, earthworms can bring additional income to farmers. Therefore the cultivation of earthworms is an important activity as a means of making better use of local resources such as livestock manure, which is widely available in the countryside (Keo Sath 2005).

In Ho Chi Minh city, Vietnam, the cultivation of earthworm has become very popular. For example, one farmer has achieved an income of 500 million Dong per year and his family’s standard of living has significantly increased since he raised earthworms (Kim Oanh 2008).

There are many methods to cultivate earthworms. Different kinds of substrate and sources of manure can be used in earthworm production such as manure from goats, cattle and pigs. According to Nguyen Quang Suc et al (2000), the rate of growth of earthworms was faster and more efficient when the substrate was manure from goats rather than from cattle.

Because of these reasons, this experiment is aimed at finding the most suitable manure for the development of earthworm production.

Hypothesis

The growth rate, manure conversion rate and the nutrient composition of earthwormswill be improved by using the goat and pig manures as feed because they have better nutritional qualities than cattle manure.

The manure as a suspension is easier for the earthworm to digest than the fresh form, therefore applying the manure as a suspension can also improve the growth rate, manure conversion rate and the nutrient composition of earthworms

Objectives

Identify the most valuable manure which can be used as feed for earthworms by comparing aqueous suspensions of manure from cattle, pigs and goats compared with solid cattle manure.

Materials and methods

Location

The experiment was conducted in Kampong Cham National School of Agriculture, Kampong Cham province, Cambodia, from 13^th August, 2008 to 13^th September, 2008.

Treatments and experimental design

The experiment was designed as a Randomized Complete Block design (RCBD) with 4 treatments and 4 replications arranged in 4 blocks (Table 1). The treatments were:

Materials

Earthworm and baskets

The earthworms (Photos 1 and 2) were the variety known as "California red worms" (Eisenia foetida) and were brought from CelAgrid (Center for Livestock and Agriculture Development), Kandal province, Cambodia.

The earthworms were cultivated in plastic baskets (40 × 60 cm) lined with plastic netting (Photo3). After applying the plastic net, six holes were made in the bottom of the plastic sheet to allow free drainage of excess moisture. Next, moistened banana leaves (200g per basket) were placed in the bottom of the basket to serve as a bed for the earthworms. 2 kg of a mixture cattle manure and water (ratio 7:3) was put as substrate in each basket. Four days later the earthworms (25g per basket) were added to the substrate.

The pig and cattle manure were bought from farmers in Kampong Cham province. The goat manure was collected from other experiments and was ground by using a hammer. Finally, water hyacinth covered the substrate surface at the rate of 500g per basket (25 per cent of the substrate weight).

The suspension of cattle manure was prepared with the ratio 50g manure and 30g water. For the pig manure, the ratio was 40g manure and 40g water and for goat manure it was 20g manure and 60g water.. These ratios were based on different contents of DM in each manure, in order to make sure that all the suspensions had the same content of DM. The daily quantities of the suspensions and the solid manure (treatment C) were added to each basket every day at 6:30 am. In order to keep the substrate moist, 150 ml of water was sprayed every 3 days per basket.

Sample collection

At the beginning of the experiment

Earthworms are sensitive to sunlight thus this characteristic is used in collecting them. After spreading the original compost containing the earthworms on a plastic net under the sunlight, they migrated to the bottom of the compost layer. Then, after about 15 minutes, the upper compost was removed in order to harvest the earthworms (Photo 4).

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 (Photo 5). A sample of the earthworms was analyzed for DM, crude protein (CP) and ash.

Samples of the manure from pigs, goats and cattle were mixed thoroughly and from 0.5 to 1 g taken for analyzing DM, CP and ash.

At the end of experiment

After harvesting the earthworms, the total weight in each basket was determined. A random sample was then 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 compost in each basket were weighed and a sample analyzed for DM, CP and ash.

The numbers of baby worms and cocoons (Photo 6) were counted in a representative sample (20 g) of the residual compost in order to determine the total quantities in each basket.

Chemical analysis

Manure, compost and earthworm were analyzed for DM, CP and ash according to AOAC (1990) procedures.

Statistical analysis

The data were analyzed by Analysis of variance (ANOVA) using the RCBD procedure of the Minitab software (version 13.3). Sources of variance were blocks, treatments and error.

Results and discussion

Earthworm performance

The location of the blocks had no effect on the numbers, lengths and weights of the earthworms (Table 2).

The suspension of goat manure helped to increase markedly not only the final weight but also the final number of worms (Table 3). The baskets with the pig manure suspension had the lowest yield. There were no differences between application of the cattle manure in solid form or as a suspension, the yields being intermediate between those for goats and pigs. The body lengths of the earthworms consuming the 4 types of manure were similar at the end of experiment. The conversion of substrate DM to earthworms was best for the goat manure and poorest for the pig manure (Figures 1 and 3). However, protein conversion rate was similar for manure from goats and cattle which were much superior to the pig manure (Figures 2 and 4). The advantages of the goat manure over the cattle and pig manure would appear to be due, at least in part, to the higher crude protein content of the former (Table 4). The better results with the cattle manure compared with that from pigs, may have been due to differences in the fiber content, as it was observed that there was more fiber in the manure from the cattle.

An important finding was the lack of difference in worm growth between cattle manure applied as a suspension or in solid form..

Table 3. Mean values for body length (cm), earthworm weight (g), number of earthworms fed by cattle manure, cattle manure suspension, goat manure suspension, pig manure suspension
	C	CS	GS	PS	SEM	Prob.
*Body length, (cm)*
Initial	7.16	7.63	7.27	7.02	0.18	0.05
Final	6.88	6.92	6.89	6.73	0.22	0.93
Length decrease	-0.29	-0.71	-0.38	-0.29	0.31	0.75
*Earthworm weight, g*
Initial weight/ basket	25	25	25	25
Final weight/ basket	47^a	49.8^a	64.3^b	37.5^a	3.12	0.001
Gain weight/DM of added substrate	0.048^a	0.053^a	0.082^b	0.026^a	0.007	0.001
Gain weight/CP of added substrate	0.805^a	0.814^a	0.985^a	0.318^b	0.088	0.002
*Earthworm number*
Initial number/basket	157	154	169	170	4.87	0.09
Final number/basket	343^a	381^a,b	506^b	329^a	34.2	0.02
Number increase/DM of added substrate	0.41^a,b	0.48^a,b	0.70^b	0.33^a	0.074	0.03
Number increase/CP of added substrate	6.82^a,b	7.48^a,b	8.45^b	4.05^a	0.988	0.057
ab Means within rows without common letter are different at P<0.05

The earthworms in one of the blocks in the more shaded area (NL2) had a lower DM content than the earthworms in the block closest to the light (L2) (Table 3). There is no obvious explanation for this difference, except perhaps that the substrate in L2 was slightly drier due to the sunlight. There were no differences among the blocks in the content of OM of the worms.

Table 3. Mean values for DM (%), OM (%) of earthworms in lighted baskets and less lighted baskets
	L1	L2	NL1	NL2	SEM	Prob.
*DM, %*	19.8^a,b	20.4^b	19.9^a,b	19.5^a	0.17	0.007
*OM, %*
Initial	91.9	91.9	91.9	91.9
Final	93.4	93.6	93.5	93.6	0.34	0.97
ab Means within rows without common letter are different at P<0.05

The crude protein content of the earthworms was high (68-75% in DM), but there were no differences due to the source of the substrate (Table 4). Content of DM and OM in the earthworms also did not differ among treatments.

Table 4. Mean values for DM (%), CP (%) and OM (%) of earthworms fed by cattle manure, cattle manure suspension, goat manure suspension, pig manure suspension.
	C	CS	GS	PS	SEM	Prob.
*DM, %*
Initial	19.4	19.4	19.4	19.4
Final	19.7	20	19.7	20.1	0.17	0.24
*CP, %*
Initial	65	65	65	65
Final	68	75.3	68.6	71		0.4
*OM, %*
Initial	91.9	91.9	91.9	91.9
Final	94.1	93.2	93.5	93.3	0.34	0.33

Types of faeces fed for California red worm didn’t make any differences in their DM (%), CP (%) and OM (%).

Cocoons and baby worms

Location of the blocks had no effect on the numbers of cocoons and baby worms per basket and as a function of the DM and CP in the substrate (Table 5).

Table 5. Mean values for number of cocoon and number of baby worm in lighted baskets and less lighted baskets
	L1	L2	NL1	NL2	SEM	Prob.
*Number of cocoons*
Cocoon/ basket	741	889	1232	872	155	0.21
Cocoon/DM of added substrate	1.56	1.88	2.61	1.84	0.33	0.21
Cocoon/CP of added substrate	21.5	26.9	37.9	25.4	4.91	0.18
*Number of baby worms*
Babyworm/ basket	3083	3431	4188	3065	656	0.61
Babyworm/DM of added substrate	6.5	7.3	8.9	6.5	1.38	0.61
Babyworm/CP of added substrate	94	104	125	93.7	18.7	0.62

There was a strong indication that there were more cocoons in the baskets with suspended cattle and goat manure (P=0.06) than in those with solid cattle manure and pig manure (Table 6). These differences were equally apparent when the numbers of cocoons were related to the amounts of DM (P=0.07) and CP (P=0.055) from the substrate (Figures 5 and 6). However, there were no differences in the numbers of baby worms due to the treatments (Figures 7 and 8), other than an indication (P=0.14) of lower numbers in the pig manure.

Compost characteristics

The residual compost in the blocks closest to the light had a lower DM content and a higher ash content but no differences were evident in the CP content (Table 7).

Table 7. Mean values for DM (%), ash (%) and CP (%) of composts in lighted baskets and less lighted baskets
	L1	L2	NL1	NL2	SEM	Prob.
DM compost, %	21.1	21.8	22.8	22.8	0.51	0.064
Ash compost, %	60.2^a,b	64.6^b	58.2^a	57^a	1.35	0.015
CP Compost, %	12.2	11.8	12.2	11.8	0.73	0.70
ab Means within rows without common letter are different at P<0.05

The sources of substrate had no effect on the DM, ash and CP content of the residual compost (Table 8).

Table 8. Mean values DM (%), ash (%) and CP (%) of composts in baskets applied by cattle manure, cattle manure suspension, goat manure suspension, pig manure suspension
	C	CS	GS	PS	SEM	Prob.
DM compost, %	21.8	22.2	22.2	22.4	0.51	0.87
CP Compost, %	11.3	12.5	13.3	11.1	1.03	0.5
Ash compost, %	58.4	58.1	61.3	62.2	1.35	0.14

Discussion

Earthworms lack teeth and sufficient digestive enzymes of their own, relying instead on microorganisms to begin the process of rotting and softening of the organic matter in the substrate, which facilitates ingestion by the earthworms. The worms also rely on naturally occurring bacteria and fungi in their digestive tract to digest their food. The bodies of these microbes are the major source of nutrients for the worms. In this way, earthworms are predators of microbial life, relying on bacteria, fungi, protozoa and algae as their major sources of nutrition. Thus, anything that will support microbial activity, is potentially a suitable food source for earthworms (Project Gutenberg 2008). According to Edwards and Bohlen (1996), earthworms gained in weight when protozoa were added to their food.

The poorer results when pig manure was the substrate may be due to it not presenting a favorable environment for the growth of microorganisms on which earthworms depend for their nutrition.

The lack of difference in worm growth between cattle manure applied as a suspension or in solid form appears to be contrary to farmer practice which favors the use of manure in suspension. However, practical experience in this experiment ndicated that it was easier, and required less time, to distribute the suspension than the solid manure. It is presumed that the farmers apply the manure in suspension for similar reasons, in that using manure in suspension facilitates application to the worm beds.

The superior growth and conversion rates of earthworms fed goat compared with cattle manure is in agreement with results reported by Nguyen Quang Suc et al (2000). Garg et al (2005) compared manure from a range of animal species but found no differences between manure from cattle and goats for growth of the same species of earthworms (Eisenia foetida). However, these authors used a different methodology in that they only applied the substrate (in solid form) at the beginning of the experiment and then every 7 days separated the worms from the substrate, later recombining them. The reported conversion for goat manure was 0.034g earthworm biomass/g of substrate DM, which is less than half of the rate recorded in the present experiment.

Conclusion

Acknowledgements

The mini-project was carried out in Kampong Cham National School of Agriculture, Cambodia. We would like to thank the SIDA- SAREC for funding this research - a part of the MSc course through the regional MEKARN project. Special thanks to Dr. Preston who gave me good advice and Mr. Chhay Ty, CelAgrid (Cambodia), Ms. Latsamy who instructed me in my experiment and my classmates, especially Giang, Nhi, Tuan, Sareoun, Sorphea, Bounthavone. I also thank to Kampong Cham National School staff who provided valuable students in helping to analyze the samples in the laboratory and preparing the materials for conducting the experiment.

References

AOAC 1990 Official methods of analysis. Association of Official Analytical Chemists, Arlington, Virginia, 15^th edition, 1298 pp.

Garg V K, Chand S, Chhillar A and Yadav A 2005 Growth and reproduction of Eisenia foetida in various animal wastes during vermicomposting. Applied Ecology and Environmental Research 3(2): 51-59

Keo Sath 2005 Effect of spraying different levels of biodigester effluent on cow and buffalo manure used as substrate for growth of earth worms, Center for Livestock and Agriculture Development (CelAgrid-UTA Cambodia). http://www.mekarn.org/MSC2005-07/protocols/sath.htm

Nguyen Duy Quynh Tram 2004 Studies into the Utilization of Pig Manure for Aquaculture in Central Vietnam, Hue University of Agriculture and Forestry, Hue City, Vietnam. www.mekarn.org/msc2003-05/theses05/tram_lit.pdf

Nguyen Duy Quynh Tram, Le Duc Ngoan and Brian Ogle 2004 Culturing earthworms on pig manure and the effect of replacing trash fish by earthworms on the growth performance of Catfish (Clarias macrocephalus x Clarias gariepinus), Hue University of Agriculture and Forestry, 102 Phung Hung St., Hue city, Vietnam, Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, P.O. Box 7024, 750 07, Uppsala, Sweden. www.mekarn.org/msc2003-05/theses05/tram_p1.pdf

Nguyen Quang Suc, Le Thi Thu Ha and Dinh Van Binh 2000 Manure from rabbits, goats, cattle and buffaloes as substrate for earthworms. http://www.mekarn.org/sarpro/sucew.htm

Table 4. Composition of the manure of pigs, cattle and goats
	Pig manure	Cattle manure	Goat manure
DM, % fresh basis	36.6	26.7	62.3
CP in DM, %	7.5	5.98	15.7
Ash, % in DM	29.9	24.5	22.8

Table 6. Mean values for number of cocoon and number of baby worm of baskets applied by cattle manure, cattle manure suspension, goat manure suspension, pig manure suspension
	PS	C	CS	GS	SEM	Prob.
*Number of cocoons*
Cocoon/ basket	622^a	753^a	1179^b	^1179b	155	0.06
Cocoon/DM of added substrate	1.29^a	1.65^a	2.50^b	2.46^b	0.33	0.07
Cocoon/CP of added substrate	15.8^a	27.6b	38.8^b	29.6^b	4.91	0.055
*Number of baby worms*
Babyworm/ basket	2916	3717	3185	3949	685	0.63
Babyworm/DM of added substrate	5.5	7.97	7.7	7.95	1.38	0.56
Babyworm/CP of added substrate	68	133	120	95.5	18.7	0.14

Effects of goat, pig and cattle manure suspensions as feed for earthworm on their performance in recycling excreta

Nguyen Hieu Phuong

Nong Lam University (NLU)
Ho Chi Minh, Vietnam
phuongnguyen180984@yahoo.com

Abstract

Keywords: Baby worms, biomass, California red worm, cocoons, compost, Eisenia foetida, growth rate

Introduction

Hypothesis

Objectives

Materials and methods

Location

Treatments and experimental design

Materials

Earthworm and baskets

Sample collection

At the beginning of the experiment

At the end of experiment

Chemical analysis

Statistical analysis

Results and discussion

Earthworm performance

Cocoons and baby worms

Compost characteristics

Discussion

Conclusion

Acknowledgements

References

Go to top

Table 1. Experimental layout
Block L1	Block L2	Block NL1	Block NL2
CS	PS	C	PS
PS	CS	CS	C
GS	GS	PS	GS
C	C	GS	CS


Eisenia foetida	Eisenia foetida
Photo 1: California red worm	Photo 2: California red worm


Photo 4: Collecting earthworms	Photo 5: Weighing earthworms

Table 2. Mean values for body length (cm), earthworm weight (g), earthworm number of lighted baskets and less lighted baskets
	L1	L2	NL1	NL2	SEM	Prob.
*Body length, cm*
Initial	7.66	7.36	7.27	6.79	0.18	0.19
Final	7.16	6.71	6.72	6.83	0.22	0.93
Length decrease	-0.51	-0.65	-0.55	0.04	0.31	0.44
*Earthworm weight, g*
Initial weight/ basket	25	25	25	25
Final weight/ basket	53	43.3	47	55.3	3.12	0.08
Gain weight/DM of added substrate	0.059	0.039	0.047	0.064	0.007	0.08
Gain weight/CP of added substrate	0.809	0.537	0.679	0.896	0.088	0.08
*Earthworm number*
Initial	164	174	167	145	4.87	0.013
Final	410	354	363	432	34.2	0.36
Number increase/DM of added substrate	0.52	0.38	0.42	0.61	0.074	0.199
Number increase/CP of added substrate	7.09	5.30	5.99	8.42	0.99	0.199


Figure 1. Mean values for earthworm gain in weight/DM of added substrate (g) of earthworms fed by cattle manure, cattle manure suspension, goat manure suspension or pig manure suspension.	Figure 2. Mean values for earthworm gain weight/CP of added substrate of earthworms fed by cattle manure, cattle manure suspension, goat manure suspension or pig manure suspension.


Figure 3. Mean values for earthworm increase number/DM of added substrate (g) of earthworms fed by cattle manure, cattle manure suspension, goat manure suspension, pig manure suspension.	Figure 4. Mean values for earthworm increase number/CP of added substrate of earthworms fed by cattle manure, cattle manure suspension, goat manure suspension, pig manure suspension.


Figure 5. Mean values for number of cocoon/DM added substrate of baskets applied by cattle manure, cattle manure suspension, goat manure suspension, pig manure suspension.	Figure 6. Mean values for number of cocoon/CP added substrate of baskets applied by cattle manure, cattle manure suspension, goat manure suspension, pig manure suspension.


Figure 7. Mean values for number of baby worm/DM added substrate of baskets applied by cattle manure, cattle manure suspension, goat manure suspension, pig manure suspension.	Figure 8. Mean values for number of baby worm/CP added substrate of baskets applied by cattle manure, cattle manure suspension, goat manure suspension, pig manure suspension.

Effects of goat, pig and cattle manure suspensions as feed for earthworm on their performance in recycling excreta

Nguyen Hieu Phuong

Nong Lam University (NLU) Ho Chi Minh, Vietnam phuongnguyen180984@yahoo.com

Abstract

Keywords: Baby worms, biomass, California red worm, cocoons, compost, Eisenia foetida, growth rate

Introduction

Hypothesis

Objectives

Materials and methods

Location

Treatments and experimental design

Materials

Earthworm and baskets

Sample collection

At the beginning of the experiment

At the end of experiment

Chemical analysis

Statistical analysis

Results and discussion

Earthworm performance

Cocoons and baby worms

Compost characteristics

Discussion

Conclusion

Acknowledgements

References

Go to top

Nong Lam University (NLU)
Ho Chi Minh, Vietnam
phuongnguyen180984@yahoo.com