Livestock Research for Rural Development 19 (12) 2007 Guide for preparation of papers LRRD News

Citation of this paper

Effect of mixtures of water spinach and fresh water hyacinth leaves on growth performance of pigs fed a basal diet of rice bran and cassava root meal

Ty Chhay, Khieu Borin and T R Preston*

Center for Livestock and Agriculture Development (CelAgrid), Pras Teat village, Rolous commune, Kandal Stung district, Kandal province. PO Box 2423 Phnom Penh 3, Cambodia
chhayty@celagrid.org
* Finca Ecológica, TOSOLY, AA #48, Socorro, Santander, Colombia

Abstract

Twenty four crossbred castrated male pigs with initial body weight from 13.7 to 15.1 kg were allocated to 6 diets containing water spinach at levels of 0, 5, 10, 15, 20 and 25% in DM, replacing fresh leaves of water hyacinth at levels of 37, 32, 27, 22, 27 and 12% in DM. The other components of the diet (DM basis) were fish meal (4-5%), soybean meal (4-5%), rice bran (26-27%) and cassava root meal (26-27%). The experiment period was 120 days. 

The replacement of 37% fresh leaves of water hyacinth by 12% water hyacinth leaves and 25% fresh water spinach (from 37 to12% of DM) with fresh water spinach (from 0 to 25% in DM) led to: (i) a 50% increase in DM intake; (ii) tripling of the rate of weight gain (from 78 to 215 g/day); and (iii) improved DM feed conversion (from 9.2 to 4.4). 

It is concluded that there are no apparent benefits from including water hyacinth leaves in diets of growing pigs.  

Key words: Growth rate, pigs, water hyacinth, water spinach


Introduction

Water hyacinth (Echhornia crassipes) floats on  water surfaces throughout SE Asia and is considered to be a common weed because of its capacity to grow and reproduce  on nutrient-rich water bodies (Le Thi Men et al 2002). Water hyacinth has been investigated since the 1979’s for the treatment of municipal water waste (Boyd 1970). The young, light-green leaves and stems are rich in crude protein (18% on a DM basis) and have been fed to pigs in the Mekong Delta (Le Thi Men 2006).

Water spinach (Ipomoea aquatica) is widely cultivated in Cambodia for human food and for feeding to pigs. Previous studies by Chhay Ty and Preston (2005) at CelAgrid showed that mixing water spinach with fresh cassava leaves (65:35 fresh basis) resulted in pig growth rates on a basal diet of broken rice, which were higher than the average recorded for diets in which water spinach or cassava leaves were fed as the sole supplement.  In a subsequent trial (Chhay Ty and Preston 2006) there were linear increases in pig growth rate when fresh water spinach replaced cassava leaves at levels of 10, 20 and 30%. 

The hypothesis that was tested in this study was that water spinach would have beneficial effects on growth rate of pigs when it replaced water hyacinth as the main source of supplementary protein in diets based on rice bran and cassava root meal. 
 

Material and methods

Location 

The experiment was carried out from 23 October 2006 to 21 February 2007 at the Center for Livestock and Agriculture Development (CelAgrid), located in Phras Teat village, Rolous Commune, Kandal stung district, Kandal province about 25km from Phnom Penh City, Cambodia. 

Experimental animals, treatments and design   

Twenty four crossbred castrated male pigs with initial body weight from 13.7 to 15.1 kg were allocated to 4 blocks according to live weight, and within blocks to 6 diets containing water spinach at levels of 0, 5, 10, 15, 20 and 25% in DM. Comparable levels of water hyacinth were: 37, 32, 27, 22, 27 and 12% in DM (Table 1). There were 4 replicates of each treatment.


Table 1.  Proportions of ingredients in the diets and estimated content of DM and crude protein (based on analysis of individual ingredients shown in Table 2).

 

WS0

WS5

WS10

WS15

WS20

WS25

Composition of diets, % DM basis

Water spinach

0

5

10

15

20

25

Water hyacinth

37

32

27

22

17

12

Fish meal

5

4

4

4

4

3.5

Soybean

5

5

4

4

4

3.5

Cassava root meal

26

26

27

27

27

28

Rice bran

26

27

27

27

27

27

Salt

1

1

1

1

1

1

Total

100

100

100

100

100

100

Analysis, %

 

 

 

 

 

 

Dry matter

59.1

58.9

58.6

58.4

58.3

58.0

Crude protein in DM, %

15.0

15.2

15.3

15.8

16.4

16.5


The pigs were housed in individual pens with concrete floor and provided with feeders and drinking nipples. The pigs were vaccinated against common diseases in Cambodia (Swine fever and salmonellosis) and were de-wormed with Ivermectin prior to being adapted to the feeds and the housing for 10 days before starting the experiment.  

Feeds, feeding and management 

Rice bran was purchased from the rice mill near CelAgrid. Cassava root meal, fish meal and soybeans were purchased from shops in Phnom Penh city. Fresh water hyacinth leaves were harvested every day from ponds in CelAgrid or in the immediate vicinity. Water spinach was purchased from traders who harvested it from lagoons receiving waste water from Phnom Penh city. 

The water hyacinth leaves were separated from the stems and chopped into small pieces prior to being mixed with the water spinach in proportions depending on the treatments. The amounts of the feeds offered were adjusted to be close to ad libitum but with minimal residues. The mixed dry meal components of the diets were offered three times daily (8.00, 12.00 and 17.00h). After the dry meals were consumed the mixed forages were offered in amounts equivalent to the intended proportion in the diet (37% of the diet DM; Table 1).  

Data collection and analyses 

The pigs were weighed every 10 days during the 120 days of the experiment. Feeds offered and residues were recorded daily. Representative samples of feeds offered and residues were taken daily to estimate DM content, the dried samples being bulked on a weekly basis for analysis of N. The DM content was determined using the microwave method of Undersander et al (1993). N was analyzed following procedures of AOAC (1990). 

Statistical analysis 

Data for weight gain, DM feed intake, and crude protein intake and feed conversion rate were analyzed using the general linear model (GLM) option of the ANOVA software of Minitab (2000). The sources of variation were blocks, treatments and error. Relationships among variables were estimated by regression analysis using the same Minitab software. 
 

Results

 
Composition of diet ingredients and feed intake

The crude protein content of the water spinach was 50% higher than in the leaves of water hyacinth (Table 2).


Table 2.  Chemical characteristics of the ingredients of the diets

 

% DM

N*6.25, % in DM

Water spinach

10.1

30.1

Water hyacinth leaves

13.8

19.9

Fish meal

88.0

34

Soybean meal

90.0

46

Cassava root meal

84.3

3

Rice bran

88.9

11

Salt

-

-


Daily DM intake (Table 3; Figure 2) increased as the proportion of water spinach in the diet increased, but there were no differences when feed intake was expressed as a proportion of live weight.


Table 3.  Mean values of feed intake of pigs fed different proportions of water spinach and fresh water hyacinth leaves as supplements to rice bran and cassava root meal

 

WS0

WS5

WS10

WS15

WS20

WS25

SEM

Prob

DM intake, g/day

Water spinach

0

53

124

175

293

341

 

 

Water hyacinth

215

167

144

130

93

54

 

 

Total foliage

35.5

35.2

40.9

38.6

48.1

44.9

-

-

Fish meal

36.3

36

41.8

39.5

49.1

46

 

 

Soybean

36.3

36.0

41.8

39.5

49.1

45.9

 

 

Rice bran

187

185

215

203

253

236

 

 

Cassava root meal

179

177

206

194

242

226

 

 

Total DM

652a

654a

771b

780bc

977de

947e

10.8

0.001

g DM/kg LW

36.7ae

36.2ac

33.1b

35.3ce

38.1d

35.3e

0.23

0.001

Crude protein intake, g/day

 

 

 

 

 

Water spinach (WS)

0

16

37.2

52.7

88.1

102

 

 

Water hyacinth

44.3

34.5

29.6

26.6

18.9

10.8

 

 

Foliage

44.3

50.5

66.8

79.3

107

113

 

 

Fish meal

12.1

12.0

13.9

13.1

16.3

15.3

 

 

Soybean

16.7

16.6

19.2

18.2

22.6

21.1

 

 

Rice bran

20.5

20.3

23.6

22.3

27.8

25.9

 

 

Cassava root meal

5.37

5.32

6.18

5.83

7.26

6.78

 

 

Total CP intake

99.0a

105a

130b

139bc

181de

182e

2.13

0.001

CP, g/kg DM

152

160

168

178

185

192

 

 

WS CP/total CP

0

0.16

0.28

0.38

0.47

0.55

0.002

0.001

abcde: Means within main effects within rows without common letter are different at P<0.05


Total intake of crude protein, and the proportion in the diet DM,  increased as water spinach replaced water hyacinth in the diet (Table 3 and Figures 1 and 3). At the highest level of water spinach, the protein from this source provided slightly more than 50% of the total diet crude protein.  



Figure 1.
 Intakes of crude protein from dietary ingredients according to level of water spinach in the diet


Figure 2.  Relationship between proportion of protein intake from water spinach and total dry matter intake

Figure 3. Relationship between proportion of protein intake from water spinach and crude protein intake


 Growth rate and feed conversion 

Growth rate was linearly and positively related to the proportion of dietary protein derived from water spinach (Table 4; Figures 4 and 5). The relationship between DM feed conversion and proportion of dietary protein derived from water spinach appeared to be curvilinear and negative (Figure 6).


Table 4.  Mean values of live weight gain and feed conversion ratio of pigs fed different proportions of water spinach and fresh water hyacinth leaves as supplements yo rice bran and cassava root meal

 

WS0

WS5

WS10

WS15

WS20

WS25

SEM

Prob

Live weight, kg

Initial

14.9

13.7

14.9

14.4

15.1

14.5

1.77

0.99

Final

24.6

25.0

35.8

35.5

40.4

42.9

3.60

0.01

Daily gain, g

78.1a

85.6a

165b

176b

207b

215b

16.3

0.001

DM feed conversion

9.24

9.71

4.59

4.49

4.68

4.42

1.22

0.014

ab: Means within main effects within rows without common letter are different at P<0.05




Figure 4.
  Growth curves of pigs fed different proportions of water spinach (WS) and
 fresh water hyacinth leaves with basal diet of rice bran and cassava root meal




               


Figure 5.  
Relationship between live weight gain and proportion
of diet protein  derived from water spinach

               


Figure 6.  
Relationship between feed conversion and proportion
of diet protein  derived from water spinach


 Discussion

The results of this study confirm our earlier research findings (Chhay Ty and Preston 2005, 2006) on the benefits of using fresh water spinach as a major protein source in diets of growing pigs.  

In contrast, there appears to be little justification for including water hyacinth in pig diets which agrees with related research done in the Mekong Delta. In these studies the levels of water hyacinth in the diets were low (5% of diet DM [Le Thi Men et al 2002]; 6% in diet DM [Luu Huu Manh et al 2002]; and 5% in the diet DM [Nguyen Ba Trung 2006]). Also in most cases the basal diets were purchased concentrates hence the nutritional significance of the supplementary water hyacinth was difficult to assess. In all these studies there were no apparent advantages from inclusion of the water hyacinth in the diets.
 

Conclusions

In diets for young growing pigs, based on rice bran and cassava root meal, the replacement of fresh leaves of water hyacinth (from 37 to12% of DM) with fresh water spinach (from 0 to 25% in DM) led to: (i) a 50% increase in DM intake; (ii) tripling of the rate of weight gain (from 78 to 215 g/day); and (iii) improved DM feed conversion (from 9.2 to 4.4).
 

Acknowledgments 

The authors would like to express their gratitude to the MEKARN project financed by SIDA-SAREC and to the Center for Livestock and Agriculture Development (CelAgrid), for providing resources for conducting this experiment.
 

References

AOAC 1990  Official Methods of Analysis. Association of Official Analytical Chemists. 15th edition (K Helrick editor). Arlington pp 1230 

Boyd C E 1970 Vascular aquatic plants for mineral nutrient removal from polluted water. Economic Botany 24: 95-103 

Chhay Ty and Preston T R 2005 Effect of water spinach and fresh cassava leaves on growth performance of pigs fed a basal diet of broken rice. Livestock Research for Rural Development. Volume 17, Article No. 76  http://www.cipav.org.co/lrrd/lrrd17/7/chha17076.htm 

Chhay Ty and Preston T R 2006 Effect of different ratios of water spinach and fresh cassava leaves on growth of pigs fed basal diets of broken rice or mixture of rice bran and cassava root meal. Livestock Research for Rural Development. Volume 18, Article No. 57. http://www.cipav.org.co/lrrd/lrrd18/4/chha18057.htm 

Luu Huu Manh, Nguyen Nhut Xuan Dung,  Seishi Yamasaki and Ryozo Takada 2002 Replacement of Concentrate by Water Hyacinth (Eichroria Crassipes): Effects on Digestibility, Feed Intake and Live Weight Gain in Pig Production.  . Proceeding of the final workshop of JIRCAS Mekong Delta project,http://www.ctu.edu.vn/institutes/mdi/jircas/JIRCAS/research/workshop/Pro02/C21-%20Replacement.pdf 

Le Thi Men 2006  Genetic and nutritional diversity of sweet potato (Ipomoea batatas), water spinach (Ipomoea aquatica) and water hyacinth (Echhornia crassipes) and their potential as pig feed in the Mekong Delta of Vietnam. Workshop-seminar "Forages for Pigs and Rabbits" MEKARN-CelAgrid, Phnom Penh, Cambodia, 22-24 August,  2006. Article #3 RetrievedJune 3, 2007, from http://www.mekarn.org/proprf/lemen.htm 

Le Thi Men, Yamasaki S, Caldwell J S, Thuan T K, Yamada R, Khoa D V A and Takada R 2002  Effect of rice based balanced resources and the water hyacinth in diet on pig production in Tan Phu Thanh village, Cantho province. Proceeding of the final workshop of JIRCAS Mekong Delta project, 1http://www.ctu.edu.vn/institutes/mdi/jircas/JIRCAS/research/workshop/Pro02/C22-%20Evaluation.pdf 

MINITAB 2000 Minitab Reference Manual release 13.31. 

Nguyen Ba Trung 2006 Agricultural potential and utilization of water hyacinth (Eichhornia crassipes) as forage for fattening pigs in the Mekong delta of Vietnam.  Workshop-seminar "Forages for Pigs and Rabbits" MEKARN-CelAgrid, Phnom Penh, Cambodia, 22-24 August,  2006. Article # 12. RetrievedJune 3, 2007, from http://www.mekarn.org/proprf/trung.htm 

Undersander D, Mertens D R and Theix N 1993  Forage analysis procedures. National Forage Testing Association. Omaha pp 154



Received 2 June 2007; Accepted 23 August 2007; Published 12 December 2007

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