Effects on the performance of growing goats by supplementing ensiled water hyacinth leaves with Melia azedarach foliage

Bui Phan Thu Hang, Vo Lam and T R Preston*

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

Abstract

Fifteen weaned crossbred goats (Bachthao x local female) with initial live weights of 11.6 (±0.45) kg were used in an experiment to evaluate the effect of increasing levels of Melia azedarach foliage as a supplement to ensiled water hyacinth leaves.

DM intake was increased by 28% by raising the  feeding level of  Melia azedarach foliage from 0.9% to 2.1% of live weight (DM basis) with the foliage accounting for 66% of total DM intake at the higher level. There was no logical trend in DM intake with higher levels of the tree foliage. Live weight gain was increased by over 60% when the  Melia azedarach content of the diet was raised from 60 to 70% of the diet DM but declined when higher levels were given. The presence of non-nutritional compounds in the leaves could be the reason for the poorer growth rate at high levels of feeding.

Key words: feed intake, foliage, water plants

Introduction

Water hyacinth (Eichhornia crassipes) has an  extremely high growth rate on water surfaces and can produce a mass of biomass throughout the year without human intervention. According to Penfound and Earle (1948) (cited by Joyce 1990) ten water hyacinth (WH) plants can give rise to over 655,000 new plants and cover 0.4 hectares in the space of eight months.  Proximate analysis indicates that WH leaves apparently have  a potentially high nutritive value (Easley and Shirley 1974; Nguyen Nhut Xuan Dung 1996), with 19.7% CP and 49.9% NDF in DM. In the Mekong delta of Vietnam, WH stems have been popularly used to make handicraft products for export and the leaves have been also used for feeding pigs, cattle and especially goats.

Melia azedarach, commonly known as bead-tree or Cape lilac (Photo 1), is a species of deciduous tree in the mahogany family, Meliaceae, that is native to Pakistan, India, Indochina, Southeast Asia and Australia (http://en.wikipedia.org/wiki/Melia_azedarach).

Melia azedarach is widely distributed throughout Vietnam and according to farmer practice has considerable potential as feed for ruminants.  According to Batcher (2000), the fruits are poisonous to humans and to some other mammals.

The objective of the present experiment was to evaluate foliage of Melia azedarach as a supplement for goats fed a basal diet of ensiled WH leaves.

Materials and Methods

Location and climate of the area

 The experiment was located in a private farm in Tinh Bien district, Long Xuyen city, Angiang province.  

Experimental design 

Fifteen weaned crossbred goats (Bach Thao x local female) with initial live weights of 11.6 (±0.45) kg were allocated to a Complete Randomized Design (CRD) with five levels of Melia azedarach foliage of 0.9, 1.2, 1.5, 1.8 and 2.1%  of live weight (DM basis) given as supplements to ensiled WH  water hyacinth leaves fed ad libitum.

Experimental feeds, animals and management

The goats were bought from smallholder goat keepers in Angiang province. They were housed in individual cages made from wood and bamboo. Before beginning the experiment, the goats were de-wormed with Ivermectin, and vaccinated against foot-and-mouth disease.

Leaves of water hyacinth were purchased from local farmers.  They were chopped into small pieces (2 to 3 cm) and ensiled in plastic bags, sealed to prevent air contamination and then put into plastic buckets to exclude mice and prevent external mechanical damage. The ensiling period was  from 7 to 14 days. The silage was fed in troughs for the goats to choose freely. The Melia azedarach foliage was hung in bunches above the feed trough. The amounts offered were decided weekly based on individual weights of the goats. Feed offered for each goat was weighed every morning and the animals were fed with 50% of their daily ration at 08:00 h and the remaining 50% at 17:00 h. Fresh water and a mineral lick were supplied free choice. 

The goats were weighed at the start of the experiment and then weekly, at the same day of the week and before feeding in the morning.  

Chemical analysis

Samples of feeds offered and refusals were analysed for DM, CP and ash according to AOAC (1990). NDF and ADF were determined according to Van Soest and Robertson (1985). 

Statistical analysis

The data from the experiment were subjected to analysis of variance using the General Linear Model (GLM) procedure of Minitab Software Release version 15 (Minitab 2007). Sources of variation were treatments and error.

Results and Discussion

The DM component in Melia azedarach foliage was twice that in WH leaf silage (Table 1). However, the CP content was similar.

Total DM intake was increased by 29% by raising the  feeding level of Melia azedarach foliage from 0.9% to 2.1% of live weight (DM basis) with the foliage accounting for 77% of total DM intake at this higher level. There was no logical trend in DM intake with higher levels of the tree foliage (Table 2, Figure 1). Live weight gain increased by over 60% when the tree foliage was increased from 0.9 to 1.5% of LW (DM basis) reflecting the higher feed intake but at higher levels appeared to decline (Table 3; Figure 2). The best growth rate can be considered as representing about 60 to 70% of the genetic potential of Bach Thao crosses, as defined by the growth rate of 114  g/day reported by Nguyen Thi Hong Nhan (1998) with a diet of 100% Sesbania grandiflora.

It is not clear why the growth rate should have declined when the level of Melia azedarach exceeded 70% of the DM intake. There are various reports of toxicity associated mainly with the fruits of Melia azedarach, caused by a group of compounds known as "tetranortriterpenoids"; the leaves are said to have insecticidal properties similar to those ascribed to leaves from the Neem tree  (Azadirachta indica) (http://en.wikipedia.org/wiki/Melia_azedarach).  According to Ngo Thanh Trung et al (2012) leaves of Melia azedarach can comprise up to 70% of the diet of goats without causing toxicity. However these authors also reported that there were no benefits on growth rate by increasing the level of Melia  azedarach  from 25 to 70% of the diet. More research is needed to identify the possible constraints to growth with high levels of Melia azedarach in the diet.

Conclusions

DM intake and daily weight gain of goats were improved when the offer level of Melia azedarach foliage was increased from 0.9 to 1.5% (as DM) of live weight.

Acknowledgements

The authors are grateful for the support from the MEKARN project, financed by the Sida-SAREC agency. The authors would also like to thank the Department of Animal Husbandry and Veterinary, Faculty of Agriculture and Natural Resources of Angiang University for infrastructure support.

References

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

Batcher M S 2000 Element Stewardship Abstract for Melia azedarach. The Nature Conservancy.

Easley  J F and Shirley R L 1974 Nutrients elements for livestock in aquatic plants. Hyacinth Control Journal, 12, 82-85.

Joyce J C 1990 Aquatic Weeds. The Ecology and Management of Nuisance Aquatic Vegetation. Oxford University Press.

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

Ngo Thanh Trung, Nguyen Xuan Trach and Preston T R 2012  Using Melia azedarach Linn.leaves in Co goat diet in Cathai island district, Haiphong. Proceedings of the International Conference "Livestock-Based Farming Systems, Renewable  Resources and the Environment", 6-9 June 2012, Dalat, Vietnam (Editors: Reg Preston and Sisomphone Southavong) http:/www.mekarn.org/workshops/dalat2012/html/trung.hua.htm

Nguyen Thi Hong Nhan 1998 Utilization of some forages as a protein source for growing goats by smallholder farmers. Livestock Research for Rural Development. Volume 10, (3) http://www.lrrd.org/lrrd10/3/nhan2.htm

Nguyen Nhut Xuan Dung 1996 Identification and evaluation of non-cultivated plants used for livestock feed in the Mekong delta of Vietnam. MSc. Thesis. Swedish University of Agricultural Sciences.

Van Soest P J and Robertson J B 1985 Analysis of forages and fibre foods. Ithaca, New York: A Laboratory Manual for Animal Science 613 Department of Animal Science, Cornell University.

Received 17 October 2012; Accepted 24 November 2012; Published 2 December 2012

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