Effect of method of offering foliage from Muntingia (Muntingia calabura) to young goats on digestibility and N retention 

Le Thi Thuy Hang

An Giang University, Long Xuyen City,
An Giang, Vietnam

Abstract

A change over design with four replicates (goats) and three periods was used to evaluate three methods of offering muntingia foliage (Muntingia calabura) to four young goats of approximately 9 kg live weight. The methods (treatments) were: hanging the foliage in the pen (MH), putting the foliage in the feed trough (MT), or putting only the leaves in the feed trough (ML). Response variables to be considered were nutrient digestibility and N balance.

DM digestibility and N retention of the Muntingia  by goats was higher when it was fed as separated leaves in the feed trough compared with the foliage fed in the trough or by hanging.  The leaves had a higher DM and crude protein concentration than foliage (leaves plus stems).

The results of this study indicate that the best method of feeding Muntingia foliage to goats is by separating the leaves from the stems and feeding this component separately in the feed trough.

Key words: Digestibility, foliage, goats, N retention, Muntingia calabura

Introduction

The major cause of low productivity of livestock, especially in the tropical regions, is the inadequate and poor quality of feeds. The main feed resources for animal are permanent pastures, crop residues and other agroindustrial by-products. Goat production in Vietnam is based on small farms and the most important feed is grass from the edges of roads, fields and ponds. However, it has been shown that rates of production are much higher when goats are fed on browse than on grasses and that infestation with intestinal nematode parasites is much less for the former system (Seng Sokerya and Rodríguez 2001; Nguyen Kim Lin et al 2003).

The method of offering the browse has also been found to be important with higher intakes and digestibility when foliage of cassava, jackfruit and mulberry were suspended in the pen rather being given in the feed trough (Theng Kouch et al 2003). Recently, the foliage from Muntingia (Muntingia calabura), a tree that is very common in Vietnam, has become the object of study by researchers  (Nguyen Xuan Ba and Le Duc Ngoan 2003; Pok Samkol 2003).

The purpose of the present communication is to report preliminary information concerning methods of offering Muntingia foliage to young goats, and the corresponding response in terms of nutrient digestibility, N utilization and some characteristics of the rumen ecosystem.

Materials and Methods

Location

The experiment took place from 4 August to 19 September 2003 at An Giang University, Vietnam.

Treatments and design

A changeover design was used with four goats with three treatments and three periods. Four local, male goats, of average live weight 9.7 ± 1.3 kg were confined in metabolism cages made from bamboo, and fed ad libitum a ration consisting of either leaves or foliage from terminal branches of Muntingia (Muntingia calabura). The branches were approximately 1 m in length and of 1 cm diameter at the cutting site and were purchased from farmers in the neighborhood of the Campus of the University, in Long Xuyen City. The trees were mature and the foliage had not previously been harvested. Some chemical characteristics of the leaves and foliage from Muntingia are set out in Table 1.

The treatments consisted of three methods of offering the feed to the goats:

• MH: Hanging the foliage above the feed trough
• MT: Putting the foliage in the feed trough
• ML: Putting only the leaves in the feed trough

Housing

The goats were confined in metabolism cages built from bamboo as described  by Theng Kouch et al (2003). The cages allowed the animals free movement and were provided with individual troughs and a bucket to supply drinking water. The cages were located in a house with roof of palm leaves and netting walls.

Feeding system

The feeding system was that previously described by Theng Kouch et al (2003). Foliage of Muntingia was collected as whole branches. For the MH method of feeding, the branches of Muntingia were hung from a bamboo stick above the cage (Photo 1).

Photo 1: The Muntingia foliage hanging from a bamboo stick	Photo 2: Leaves of Muntingia in the feed trough

 

In the MT treatment, the foliage was placed in the feed trough. For ML the leaves were separated from stems, and then put in the feed trough (Photo 2). In all cases, feeding was ad libitum and an estimated level of about 20% above actual intake was given to the animals. The goats were weighed at the beginning of each adaptation period in the morning before offering feed.  Every experimental period lasted nine days: days 1 to 4 were for adaptation to the new treatment, and days 5 to 8 were for faeces and urine collection.

During the collection period, faeces were quantitatively collected twice daily and stored at -20^o C until analyzed. Urine was collected in a bucket containing 50 ml of 25% sulphuric acid to keep the pH below 4 so as to prevent escape of ammonia. The weight of feeds offered and refused was carefully recorded during every collection period.

Measurements

Nutrient digestibility and N balance were calculated by standard procedures outlined for the direct estimation of animal digestibility.

Chemical analysis

Feed and faeces samples were dried by micro-wave radiation to measure the DM content (Undersander et al 1993). Total N of feed, faeces and urine was measured by the Kjeldahl procedure as outlined by the AOAC (1990).

Statistical analysis

Data were analyzed with the GLM option of the ANOVA software of Minitab version 13.31.  Sources of variation were animals, periods, feeding system and error.
 

Results and discussion

Animal status

During the experiment all animals were in good health and in positive live weight balance.

Nutrient digestibility and N retention

Dry matter intake was highest when the foliage was hung in the feed trough and lowest when it was placed in the feed trough (Table 3). This agrees with the findings of Theng Kouch et al (2003) who compared the same three feeding systems with jackfruit, mulberry and cassava foliages.  Faecal DM content was lower when the foliage was hung than when given in the feed trough as foliage. DM digestibility tended to be highest when only the leaves were fed, and lowest when the foliage was put in the feed trough (P=0.084).   This is the opposite effect to that reported for goats in Cambodia (Theng Kouch et al 2003) where DM and OM digestibility were higher for Jackfruit, mulberry and cassava foliages hanging in the  than when the separated leaves were put in the feed trough.  It is not known if this effect on digestibility is related to differences in the composition of the Muntingia compared with the foliages used by Theng Kouch et al (2003).

 N retention was higher, on daily basis, and as percentage of intake,  when the leaves were fed in the trough compared with the other two methods (Table 4). These results also differ from the findings of Theng Kouch et al (2003) where N retention was higher for the method of hanging the foliage compared with feeding only the leaves.

 

Conclusions

• The results of this study indicate that feeding Muntingia foliage to goats as separated leaves results in higher digestibility and N retention, compared with feeding the foliage in which the leaves were attached to the stems.

Acknowledgments

I wish to acknowledge  the support of the  MEKARN project, funded by SIDA - SAREC of Sweden, that enabled me to participate in this course. I am grateful to Dr T R Preston and to  Dr J Ly for help in the preparation and interpretation the data, and to Mr Chhay Ty  for help in the analysis of the samples. In addition, Dr Vo-Tong Anh and all of the people in the Faculty of Agriculture and Natural Resources of An Giang University are acknowledged for facilitating my study in An Giang University.

References

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

Ly J and PrestonT R 2001. In vitro estimates of nitrogen digestibility for pigs and water-soluble nitrogen are correlated in tropical forage feeds. Livestock Research for Rural Development 13(1): http://www.cipav.org.co/lrrd/lrrd13/1/ly131.htm

Nguyen Xuan Ba and Le Duc Ngoan  2003: Evaluation of some unconventional trees/plants as ruminant feeds in Central Vietnam;  Livestock Research for Rural Development (15) 6 Retrieved, from http://www.cipav.org.co/lrrd/lrrd15/6/ba156.htm

Nguyen Kim Lin, Preston T R , Dinh Van Binh and  Nguyen Duy Ly 2003  Effects of tree foliages compared with grasses on growth and intestinal nematode infestation  in confined goats. Livestock Research for Rural Development (15) 6 Retrieved September 26, 2003, from http://www.cipav.org.co/lrrd/lrrd15/6/lin156.htm

Pok Samkol 2003 Effect of method of offering muntingia (Muntingia calabura) foliages to goats on intake and eating and ruminating time. Miniproject 4 Final Report. Mekarn MSc. http://www.mekarn.org/miniproject 4/samkol.htm

 

Seng Sokerya and Rodriguez Lylian 2001 Foliage from cassava, Flemingia macrophylla and bananas compared with grasses as forage sources for goats: effects on growth rate and intestinal nematodes. Livestock Research for Rural Development 13(2): http://www.cipav.org.co/lrrd/lrrd13/2/soke132.htm

Theng Kouch, Preston T R and Ly J 2003 Studies on utilization of trees and shrubs as the sole feedstuff by growing goats: foliage preferences and nutrient utilization. Livestock Research for Rural Development 15(7): http://www.cipav.org.co/lrrd/lrrd15/7/Kouc157.htm

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