Silage of banana pseudo-stem and taro foliage as replacement for rice bran fed to common ducks

Dao Thi My Tien, Ngo Thuy Bao Tran, Bui Phan Thu Hang and T R Preston*

Angiang University, Faculty of Agriculture and Natural Resources, Vietnam,
dtmtien@agu.edu.vn
* Finca Ecológica, AA48 Socorro, Santander, Colombia

Abstract

The aim of this experiment was to evaluate the effect of the ensiled mixture of banana stem and taro foliage as a partial replacement of rice bran in the diet of growing common ducks. The design was a completely randomized arrangement of  five treatments and three replicates. The treatments were based on percentages of silage of banana stem and taro foliage (50:50, DM basis) replacing rice bran in the diet (0, 20, 30, 40 and 50% as DM). The average crude protein content of the diets was in the range of 11 to 13% in DM.

 DM intake decreased and DM feed conversion was improved when the banana stem-taro silage replaced rice bran.  Live weight gain increased with a curvilinear trend  with the optimum (13 g/day) between 30 and 40% banana stem-taro silage in the diet.

Key words: feed conversion, feed intake, leaves, petioles, soluble sugars

Introduction

Banana trees (Photo 1) are widely planted in Vietnam. They can grow very easily mostly without fertilizer and pesticide. Commonly, most parts of banana trees are used as human food (banana fruits, flowers and even the banana root (Dao Cong Ho 2009). In some areas of Viet Nam, banana stems are also used as feed for pigs and poultry. According to Bui Quang Tuan and Nguyen Van Hai (2004), banana stem contains a lot of water (93.4%) and has rather low nutritional value (6.5% CP and 1.5% lipids on DM basis). It is predicted hypothesised that the banana plant is one species that will find increasing acceptance in the future  as global warming continues to raise ambient temperatures.

Taro (Colocasia esculenta) is a wetland plant that grows widely in Vietnam, usually near river banks and ponds (Photo 2). It has been shown that species of the Taro family can be ensiled easily, especially if the stems are included in the process (Rodríguez and Preston 2009). Giang et al (2010) and Chhay Ty et al (2011) have reported that ducks grow well on a diet of 100% ensiled taro foliage (leaves and stems). According to pilot observations (Dao Thi My Tien et al 2010), banana stems can be ensiled easily, especially if combined with taro foliage (Figure 1).  This is because there are quite high concentrations of soluble sugars in the juice of both the banana stem and the taro foliage (Figure 2).

Photo 1. Banana plant in Vietnam	Photo 2. Taro (Colocasia esculenta)

Figure 1. Pattern of pH change in ensiled banana pseudo-stem (BS) with and without incorporation (50:50 DM basis) of Taro foliage (changes in the pH of Taro silage are also shown)	Figure 2. Change of soluble sugars in ensiled banana pseudo- stem (BS) with and without incorporation (50:50 DM basis) of Taro foliage (changes in Taro silage are also shown)

 It is hypothesised that the banana plant is one species that will find increasing acceptance in the future  as global warming continues to raise ambient temperatures. Thus the objective of this study was to evaluate silage made from combinations of banana pseudo-stem and taro foliage as replacement for rice bran in the diet of growing ducks.

Materials and methods

Location and duration

The experiment was carried out in the experimental farm of Angiang University, Longxuyen City, Angiang province, Vietnam, from February to April 2011.

Animals and management

One hundred and twenty common ducks at 1 day old were collected from brooding houses in Angiang province. For one week they were fed a commercial feed and then gradually adapted to the experimental diet until they reached 21 days old. The ducks were housed in cages (5 ducks/m²) made from wood and net arranged on the cement floor (with rice husk for bedding).

Experimental design

The experiment was arranged as a Completely Randomized Design with five treatments and three replicates (8 ducks per treatment, balanced for sex).  The treatments were based on percentages of the silage of banana stem and taro foliage (BT) (ensiled 50:50 ratio, DM basis) and rice bran (RB) in the proportions of 0, 10, 20, 30, 40 and 50% (BT) of the diet (DM basis) (Table 1). 

Experimental feeding

Both banana stem and taro foliage (stem and leaves) were chopped into small pieces (1-2 cm in length) (Photos 3 to 5), dried under sun light for half a day and ensiled in plastic bags (50 liter capacity) for 7 days before use.  The experimental diets were fed at 7% live weight (DM basis). Water was supplied ad libitum. Both feeders and drinkers were cleaned and refilled each morning. The experiment lasted 50 days (starting when ducks reached 21 days old and finished when they reached 70 days)

Data collection

The ducks in each experimental unit were weighed individually at the beginning of the experiment and then weekly until the end of the experiment. Daily feed intakes were calculated according to the total feed consumption of the ten ducks in each pen.  Feeds offered and refused were measured separately every day in the morning.

Chemical analysis

The DM, CP and ash in the feeds were determined according to AOAC (1990).

Statistical analysis

The data were organized with MS Excel software for subsequent statistical analysis, using the general linear model in the ANOVA program of the Minitab (2007) software (release15). Sources of variation in the model were treatments and error.

Results and discussion

Chemical composition of the diets

The crude protein in the ensiled mixture of banana stem and taro foliage was slightly less than in the rice bran (Table 2). The ensiled mixture of banana pseudo stem was a good source of minerals.

Growth performance, feed intake and feed conversion

DM intake decreased linearly when the banana stem-taro silage replaced rice bran (Table 3; Figure 3). By contrast, live weight gain showed a positive curvilinear response to inclusion of banana stem-taro silage in the diet with the optimum at between 30 and 40% of silage in the diet (Figure 4). DM feed conversion was improved by inclusion of the silage in the diet up to the 30% level with no further improvement at 40 and 50% silage in the diet DM  (Figure 5). These responses are similar to those reported by Chhay Ty et al (2011) when they included increasing proportions of ensiled taro foliage in a basal diet of rice bran fed to common ducks in Cambodia.

Figure 3. Trends in DM intake as the ensiled mixture of banana stem and taro foliage replaced rice bran in the diet of common ducks	Figure 4. Trends in live weight gain as the ensiled mixture of banana stem and taro foliage replaced rice bran in the diet of common ducks
Figure 5. Trends in DM feed conversion as the ensiled mixture of banana stem and taro foliage replaced rice bran in the diet of common ducks

Conclusions

• DM intake decreased and DM feed conversion and  live weight gain were improved when banana stem-taro silage replaced rice bran up to the 30-40% level in the diet of growing common ducks. 

Acknowledgement

The authors are grateful for the support from the MEKARN project, financed by Sida, Sweden. 

References

AOAC 1990 Official Methods of Analysis, 15^th edition. Association of the Official Analytical Chemists, Washington D.C.

Bui Quang Tuan and Nguyen Van Hai 2004 Research on using banana stem as feed for crossbred milking calves. Journal of Agricultural Science. Volume 2 No. 1/2004

Chhay Ty, Borin K, Chanpheakdey S, Sina V, Buntho H and Preston T R 2011 Replacing rice bran and duckweed with ensiled Taro leaf-stem foliage (Colocasia esculenta) in diets of growing ducks. Livestock Research for Rural Development. Volume 23, Article #92. http://www.lrrd.org/lrrd23/4/chha23092.htm

Dao Cong Ho 2009 Cây chuối – món ăn ngon và vị thuốc quý http://www.khuyennongvn.gov.vn/k-ban-co-biet/cay-chuoi-mon-an-ngon-va-vi-thuoc-quy (In Vietnamese)

Dao Thi My Tien, Nguyen Tuyet Giang and Preston T R  2010 A note on ensiling banana pseudo-stem with Taro (Colocasia esculenta) leaves and petioles. http://www.mekarn.org/workshops/pakse/abstracts/tien_agu2.htm

Giang N T, Preston T R and Ogle B 2010 Effect on the performance of common ducks of supplementing rice polishings with taro (Colocacia esculenta) foliage. Livestock Research for Rural Development. Volume 22, Article #194. http://www.lrrd.org/lrrd22/10/gian22194.htm

Minitab 2007 Reference Manual, Release 15 for Windows. Minitab Inc., USA.

Rodríguez L and Preston T R 2009 A note on ensiling the foliage of New Cocoyam (Xanthosoma sagittifolium). Livestock Research for Rural Development. Volume 21, Article #183. http://www.lrrd.org/lrrd21/11/rodr21183.htm

Received 19 February 2013; Accepted 1 March 2013; Published 2 April 2013

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