Gum arabic tree (Acacia senegal)

Datasheet

Description

Click on the "Nutritional aspects" tab for recommendations for ruminants, pigs, poultry, rabbits, horses, fish and crustaceans

Common names

Gum arabic tree, gum acacia, Senegal gum, Sudan gum arabic, kher [English]; acacia Sénégal, gommier blanc, acacia à gomme arabique [French]; Driehaakdoring [Afrikaans]; Gummiarabikumbaum, Senegal-Akazie [German]; Umukonji [Kinyarwanda]; Arap zamkı [Turkish]; סנגליית סנגל [Hebrew]; アラビアガム [Japanese]; Акация сенегальская [Russian]

Species

Acacia senegal (L.) Willd. [Fabaceae]

Synonyms

Senegalia senegal (L.) Britton, Acacia circummarginata Chiov., Acacia cufodontii Chiov., Acacia glaucophylla sensu Brenan, Acacia kinionge sensu Brenan, Acacia oxyosprion Chiov., Acacia rupestris Boiss., Acacia senegal (L.) Willd. subsp. modesta (Wall.) Roberty, Acacia senegal (L.) Willd. subsp. senegalensis Roberty, Acacia somalensis sensu Brenan, Acacia sp. F. White, Acacia spinosa Marloth & Engl., Acacia thomasii sensu Brenan, Acacia volkii Suess., Mimosa senegal L.

Taxonomic information

The taxon Senegalia senegal (L.) Britton is recognized by some authors as the correct one for the gum arabic tree. However, the name Acacia senegal (L.) Willd. remains widely in use.

Related feed(s)

Description

The gum arabic tree (Acacia senegal (L.) Willd. or Senegalia senegal (L.) Britton) is a legume tree from the dry tropics and subtropics. It is valued for the production of gum arabic, the only acacia gum evaluated as a safe food additive. The leaves and pods are browsed by livestock.

Morphological description

The gum arabic tree is a low branching, small, and spiny tree, which grows up to 7-15 m in height with a girth of about 1.3 m (Kew Gardens, 2016; Duke, 1983). It has a rounded, flat-topped crown (Orwa et al., 2009). The tree is deciduous, dropping its leaves during the dry season. Under dry conditions, the taproot develops to a great depth allowing the tree to become larger than usual. The trunk is about 30 cm in diameter and is covered by a greyish-white bark that becomes dark, scaly and thin in old trees (Kew Gardens, 2016; Orwa et al., 2009; Bekele-Tesemma, 2007). The tree bears prickly branches, armed with three hooked thorns, up to 7 mm long, just below the nodes. The leaves are pinnately compound, 3.5-8 cm long. Their rachis may be spiny. The leaflets are linear to oblong, 1-9 mm long and 0.5-3 mm wide. They may be sparsely hairy and a pale glaucous green in colour (Kew Gardens, 2016; Bekele-Tesemma, 2007). The yellowish-white and fragrant flowers are borne on cylindrical spikes, 5-10 cm long. The fruits are straight, hairy, flat, dehiscent papery pods, about 7 cm long x 2 cm wide. Green and pubescent when young, they become a shiny bronze with maturity. They contain 3-6 smooth, flat shiny seeds (Kew Gardens, 2016; Bekele-Tesemma, 2007).

Uses

The most important use of the gum arabic tree is the harvest of gum arabic, an exudate from the bark that is tapped for this purpose during the dry season (Orwa et al., 2009). Several thousand tons of gum arabic are internationally traded every year, mainly in Europe and the USA (Kew Gardens, 2016). Gum arabic has many commercial uses: food (flavour fixative, emulsifier, stabilizer of dairy products), pharmaceutics (these two sectors representing 60-75% of the use of gum arabic), and industrial products (inks, pigments, polishes) (Kew Gardens, 2016). Gum arabic was reported to have antidotal effects as it can destroy many alkaloids (Duke, 1983). Acacia senegal seeds are traditionally used for human nutrition in Rajasthan (Ram et al., 2014). The wood is valued as firewood, and can be used to produce charcoal. The wood is also used to make utensils, poles and fence-posts. The bark and the roots provide fibre and make strong ropes and fishing nets (Orwa et al., 2009; Duke, 1983). Gum arabic trees provide valuable fodder to sheep, goats and camels. Leaves and pods are browsed by domestic and wild ruminants. Flowers provide valuable nectar to bees for honey production (Orwa et al., 2009).

Distribution

The gum arabic tree is native to Western Sudan, Nigeria and the Arabian Peninsula. It is commonly found in tropical areas of Western and Central Africa, and in Eastern Africa from Mozambique to South Africa (Kew Gardens, 2016). It was introduced into Egypt, Australia, Puerto Rico, the Virgin Islands, and South Asia. It is cultivated in India, Pakistan and Nigeria. Gum arabic trees grow where annual rainfall is in the range of 380 to 2280 mm, and annual mean temperatures between 16.2°C and 27.8°C. It cannot survive frost but is particularly tolerant of drought. The gum arabic tree thrives in the drier parts of Sudan and in the Northern Sahara. It can survive in places where drought lasts for 11 months. It thrives on rocky slopes and sandy soils, but also on clay plains and cotton soils with a pH ranging from 5 to 8 (Kew Gardens, 2016).

Forage management

Establishment

Acacia senegal is mainly propagated by seeds. These should be harvested before the pods have dried in order to prevent insect attacks, and then treated with an insecticide, after which they will remain viable for many years in hermetic storage at 10°C. Before planting, seeds collected in a previous season should be soaked or nicked, or put in a sulphuric acid solution for 3-15 minutes and then dropped in boiling water for 5 seconds to break the seed dormancy (Kew Gardens, 2016; Bekele-Tesemma, 2007). For vegetative reproduction, shoot cuttings are used, and seedlings should be watered every 7th day (Orwa et al., 2009). Gum arabic trees can be raised in nurseries or directly in the field. As the tree is slow to establish, the field must be carefully weeded prior to planting (Orwa et al., 2009). Planting should be done with a minimum spacing of 4 m x 4 m in pure stands or 10 m x 10 m in intercropping systems (with millet, beans or groundnuts). Young plants should be protected from grazing animals. The gum arabic tree can be tapped after 4 years and remain productive up to 20 year-old (Duke, 1983).

Yield

Gum arabic trees are mostly used for tapping gum arabic. Higher yields of gum arabic are obtained under adverse conditions, which is contrary to forage yield. Forage production from gum arabic tree thus remains below that of other sahelian trees, which limits its use as forage (Ickowicz et al., 2005).

Environmental impact

Soil binder and soil improver

Gum arabic trees can help prevent desertification through dune stabilisation and by acting as a wind break. It is valued in agroforestry systems where it is combined with crops such as millet, sorghum, sesame, and groundnut, and where it is reported to improve soil fertility, though its N-fixing status is debated (Orwa et al., 2009).

Nutritional aspects

Nutritional attributes

Gum arabic tree leaves are of good nutritional value, with a protein content ranging from 15 to 33% of DM when the leaves are fresh. The leaves are also relatively low in fibre (crude fibre 14-25% of DM). The pods are also rich in protein but with a higher fibre content.

Potential constraints

No reports of toxicity could be found (2016). Like other acacia species, the foliage of Acacia senegal contains tannins.

Ruminants

Gum arabic tree leaves are a valuable forage for all ruminants except cattle. Though forage yield remains low, leaves are relished by livestock, and provide good quality forage with high protein content and digestibility (in vitro OM digestibility ranges from 66 to 86%), and a low tannin content. Gum arabic tree forage is available at the end of the dry season, when other forages are still scarce. At that time the leaves may account for up to 15-20% of the feed intake of sheep and camelids, and 45% and above for goats. In terms of its relative palatability, Acacia senegal ranks highest among local fodder species (Ickowicz et al., 2005).

Pods are palatable to livestock but their consumption destroys seed stocks and may have deleterious effects on stand management (Ickowicz et al., 2005). It was shown that only 33% of gum arabic tree seeds could be retrieved from cattle faeces, and only 1% from sheep and goats. Their viability was moreover significantly reduced: 1% germination for seeds found in cattle faeces and no germination for those retrieved from sheep and goats faeces (Danthu et al., 1996).

Poultry

No information was available on the use of Acacia senegal leaf meal or seeds for poultry (September 2016). Some trials have been done on the use of gum arabic and the performance of broilers and layers.

Gum arabic

Broilers

When gum arabic was used at relatively high levels (2 to 7%) in the diet, feed intake tended to increase, while weight gain was unaffected or slightly increased (Al-Fadil et al., 2013; Abdalla et al., 2015). The effect on feed efficiency was not significant, although a slight degradation occurred (Abdalla et al., 2015). No major effect was observed on physiological parameters. In an experiment with lower levels of gum arabic (0.6%) used as prebiotic, feed intake was reduced and weight gain increased, leading to a significant improvement in feed efficiency (Maken, 2015).

Layers

In layers fed diets containing 5 to 15% gum arabic, feed intake was slightly increased while egg production decreased (El-Khier et al., 2009). With lower levels, no major change in performance was recorded, but body weight was increased (Abd-Razig et al., 2010). The lipid profile was affected and cholesterol tended to decrease in blood and eggs (El-Khier et al., 2009).

Rabbits

No information on the direct use of Acacia senegal forage or seeds in feeding of domestic rabbits is available in the international literature (May 2016). However, some studies report the possibility of safe utilisation of gum arabic in rabbit nutrition, for example up to 7% of the diet at the expense of sorghum grain (Ibrahim, 2007) or at the expense of sucrose or starch (Hove et al., 1957). Ethanol extracts of Acacia senegal seeds administered by mouth to atherosclerotic rabbits (500 mg/kg live weight/day) were proved to be actively anti-atherosclerotic (Ram et al., 2014). These studies proved that no toxic or anti-nutritional substances seem present in this plant as far as rabbit feeding is concerned.

As forage, pods and seeds are consumed by other livestock (and occasionally by humans), they can probably be used safely in rabbit feeding as a source of protein (seeds and leaves), or as a source of fibre (leaves and pods). However, direct experiments are recommended before any extensive use as a feed for rabbits.

Nutritional tables

Tables of chemical composition and nutritional value

Avg: average or predicted value; SD: standard deviation; Min: minimum value; Max: maximum value; Nb: number of values (samples) used

Gum arabic tree (Acacia senegal), leaves, fresh

Main analysis	Unit	Avg	SD	Min	Max	Nb
Dry matter	% as fed	40.8	6.1	28.3	48.3	7
Crude protein	% DM	23.8	4.7	14.5	33.4	43
Crude fibre	% DM	18.2	3.3	14.4	25.4	19
NDF	% DM	36.5	7.9	24.9	51.0	28
ADF	% DM	20.7	5.8	13.3	34.2	30
Lignin	% DM	7.0	2.3	3.6	14.6	29
Ether extract	% DM	3.6	0.9	2.2	5.4	19
Ash	% DM	12.0	2.9	6.1	18.8	41
Gross energy	MJ/kg DM	18.1					*

Minerals	Unit	Avg	SD	Min	Max	Nb
Calcium	g/kg DM	27.4	10.7	14.4	43.7	8
Phosphorus	g/kg DM	2.0	1.2	0.8	4.7	8
Potassium	g/kg DM	12.9	5.3	7.3	21.6	5
Magnesium	g/kg DM	3.8	1.5	2.6	6.1	5

Secondary metabolites	Unit	Avg	SD	Min	Max	Nb
Tannins (eq. tannic acid)	g/kg DM	21.4	59.9	0.0	217.0	13
Tannins, condensed (eq. catechin)	g/kg DM	11.4	21.7	0.0	54.2	6

In vitro digestibility and solubility	Unit	Avg	SD	Min	Max	Nb
OM digestibility, pepsin-cellulase	%	78.3	5.9	66.0	85.7	14

Ruminant nutritive values	Unit	Avg	SD	Min	Max	Nb
OM digestibility, ruminants	%	83.1					*
Energy digestibility, ruminants	%	80.0					*
DE ruminants	MJ/kg DM	14.5					*
ME ruminants	MJ/kg DM	11.4					*
a (N)	%	16.7		16.3	17.0	2
b (N)	%	48.5		23.9	73.0	2
c (N)	h-1	0.069		0.031	0.107	2
Nitrogen degradability (effective, k=4%)	%	47					*
Nitrogen degradability (effective, k=6%)	%	43		25	89	2	*

The asterisk * indicates that the average value was obtained by an equation.

References

Abdulrazak et al., 2001; CIRAD, 1991; Fall Touré, 1991; Osuga et al., 2007; Rubanza et al., 2005; Sanon et al., 2008; Wilson et al., 1963

Last updated on 19/09/2016 13:51:17

Gum arabic tree (Acacia senegal), pods, dry

Main analysis	Unit	Avg	SD	Min	Max	Nb
Dry matter	% as fed	93.1	1.9	91.0	95.6	4
Crude protein	% DM	20.3	2.7	16.4	23.5	5
Crude fibre	% DM	33.3	4.3	29.6	39.0	4
NDF	% DM	52.4	7.2	48.7	63.2	4
ADF	% DM	36.2	2.8	33.8	40.2	4
Lignin	% DM	10.3	4.6	5.5	16.4	4
Ether extract	% DM	2.0	1.2	0.9	3.9	5
Ash	% DM	9.0	4.5	5.3	17.8	6
Gross energy	MJ/kg DM	18.6					*

Minerals	Unit	Avg	SD	Min	Max	Nb
Calcium	g/kg DM	11.2	4.1	6.8	15.0	3
Phosphorus	g/kg DM	1.8	0.8	0.9	2.4	3
Potassium	g/kg DM	15.6	1.0	14.8	16.7	3
Sodium	g/kg DM	0.0				1
Magnesium	g/kg DM	2.8	0.3	2.7	3.1	3
Manganese	mg/kg DM	184				1
Zinc	mg/kg DM	22				1
Copper	mg/kg DM	6				1

Secondary metabolites	Unit	Avg	SD	Min	Max	Nb
Tannins (eq. tannic acid)	g/kg DM	0.6		0.0	1.1	2

Ruminant nutritive values	Unit	Avg	SD	Min	Max	Nb
OM digestibility, ruminants	%	83.5					*
Energy digestibility, ruminants	%	81.0					*
DE ruminants	MJ/kg DM	15.1					*
ME ruminants	MJ/kg DM	11.8					*
Nitrogen digestibility, ruminants	%	73.0				1

The asterisk * indicates that the average value was obtained by an equation.

References

CIRAD, 1991; Sanon et al., 2008; Wilson et al., 1963

Last updated on 19/09/2016 13:48:50

References

Abd-Razig, N. M.; Sabahelkhier, M. K.; Idris, O. F., 2010. Effect of gum arabic (Acacia senegal L. Willd) on lipid profile and performance of laying hens. J. Appl. Biosci., 32: 2002–2007
Abdalla, S. A.; Abdel-Atti, K. A.; Malik, H. E. E.; Dousa, B. M.; Elamin, K. M., 2015. Effect of dietary inclusion of gum arabic (Acacia senegal) on performance and blood chemistry of broiler chicks. Global J. Anim. Sci. Res., 3 (2): 305-310
Abdulrazak, S. A.; Orden, E. A.; Ichinohe, T.; Fujihara, T., 2000. Chemical composition, phenolic concentration and in vitro gas production characteristics of selected acacia fruits and leaves. Asian-Aust. J. Anim. Sci., 13 (7): 935-940
Abdulrazak, S. A. ; Nyangaga, J. ; Fujihara, T., 2001. Relative palatability to sheep of some browse species, their in sacco degradability and in vitro gas production characteristics. Asian-Aust. J. Anim. Sci., 14 (11): 1580-1584
Al-Fadil, S.; Mukhtar, M. A.; Tabidi, M. H., 2013. Response of broiler chicks to diets containing gum arabic as natural prebiotic. J. Curr. Res. Sci., 1 (4): 247-253
Bekele-Tesemma, A., 2007. Useful trees and shrubs of Ethiopia: identification, propagation and management for 17 agroclimatic zones. In: Tengnäs, B.; Kelbesa, E.; Demissew, S.; Maundu, P. (Eds.), RELMA in ICRAF Project World Agroforestry Centre, Nairobi, Kenya
Bennison, J. J. ; Paterson, R. T., 1993. Use of trees by livestock 2: Acacia. Chatham, UK: Natural Resources Institute, 32 p.
Danthu, P.; Ickowicz, A.; Friot, D.; Manga, D.; Sarr, A. , 1996. Effet du passage par le tractus digestif des ruminants domestiques sur la germination des graines de légumineuses ligneuses des zones tropicales sèches. Rev. Elev. Med. Vet. Pays trop., 49 (3): 229-234
Duke, J. A., 1983. Handbook of Energy Crops. NewCROPS web site, Purdue University
El-Khier, M. K. S. ; Ishag, K. E. A.; El Gasim, A.; Yagoub, A.; Abu Baker, A. A., 2009. Supplementing laying hen diet with gum arabic (Acacia senegal): effect on egg production, shell thickness and yolk content of cholesterol, calcium and phosphorus . Asian J. Poult. Sci., 3 (1): 9-14
Fall Touré, S., 1991. In vitro digestibility and degradability in situ in the rumen of woody forage available on natural grasslands in Senegal. First results. Rev. Elev. Méd. Vét. Pays Trop., 44: 345-354
Hailemariam, S.; Urge, M.; Menkir, S., 2016. Effect of feeding Neem (Azadirachta indica) and Acacia (Acacia senegal) tree foliage on nutritional and carcass parameters in short-eared Somali goats. Trop. Anim. Health Prod., 48 (2): 461-464
Hove, E. L.; Herndon, J. F., 1957. Growth of rabbits on purified diets. J. Nutr. , 63 (2): 193-199
Ibrahim, S., 2007. Response of rabbits to dietary Gum arabic. Doct. dissert., Fac. Anim. Prod., Univ. Khartoum, Sudan, 70 pp.
Ickowicz, A.; Friot, D.; Guérin, H., 2005. Acacia senegal, a fodder tree for the Sahel?. Bois et Forêts des Tropiques, 284 (2): 59-69
INFIC, 1978. Data from International Network of Feed Information Centres. Rome, FAO
Kew Gardens, 2016. Acacia senegal (gum arabic). Board of Trustees of the Royal Botanic Gardens, Kew
Kyalangalilwa, B. ; Boatwright, J. S. ; Daru, B. H. ; Maurin, O. ; van der Bank, M., 2013. Phylogenetic position and revised classification of Acacia s.l. (Fabaceae: Mimosoideae) in Africa, including new combinations in Vachellia and Senegalia. Bot. J. Linn. Soc., 172 (4): 500–523
Maken, E. K. A., 2015. Effect of feeding gum Arabic (Acacia senegal) with or without commercial Xylam 500 enzymes on the performance of broiler chicks. M.Sc. thesis, Sudan University of Science and Technology, Khartoum, Sudan
Ondiek, J. O.; Abdulrazak, S. A.; Njoka, E. N., 2010. Chemical and mineral composition, in-vitro gas production, in-sacco degradation of selected indigenous Kenyan browses. Livest. Res. Rural Dev., 22 (2): 25
Orwa, C.; Mutua, A.; Kindt, R.; Jamnadass, R.; Anthony, S., 2009. Agroforestree Database: a tree reference and selection guide version 4.0. World Agroforestry Centre, Kenya
Osuga, I. M. ; Maindi, C. N. ; Abdulrazak, S. A. ; Nishino, N. ; Ichinohe, T. ; Fujihara, T., 2007. Potential nutritive value and tannin bioassay of selected Acacia species from Kenya. J. Sci. Food Agric., 87 (8): 1533-1538.
Ram, H.; Jatwa, R.; Purohit, A., 2014. Antiatherosclerotic and cardioprotective potential of Acacia senegal seeds in diet-induced atherosclerosis in rabbits. Biochem. Res. Int., Article ID 436848, 6 pp.
Sanon, H. O.; Kaboré-Zoungrana, C.; Ledin, I., 2007. Behaviour of goats, sheep and cattle and their selection of browse species on natural pasture in a Sahelian area. Small Rumin. Res., 67 (1): 64–74
Sanon, H. O. ; Kaboré-Zoungrana, C. ; Ledin, I., 2008. Nutritive value and voluntary feed intake by goats of three browse fodder species in the Sahelian zone of West Africa. Anim. Feed Sci. Technol., 144 (1): 97-110
Sanon, H. O.; Kabore-Zoungrana, C.; Ledin, I., 2008. Growth and carcass characteristics of male Sahelian goats fed leaves or pods of Pterocarpus lucens or Acacia senegal. Livest. Sci., 117 (2-3): 192-202
Skerman, P. J., 1982. Les légumineuses fourragères tropicales. FAO, Rome, 666 p.
Stuth, J. W. ; Kamau, P. N., 1990. Influence of woody plant cover on dietary selection by goats in an Acacia senegal savanna of East Africa. Small Rumin. Res., 3 (3): 211-225
Wilson, J. G. ; Bredon, R. M., 1963. Nutritional value of some common cattle browse and fodder plants of Karamoja, Northern Province, Uganda. E. Afr. Agric. For. J., 28: 204-208

Datasheet citation

Heuzé V., Thiollet H., Tran G., Hassoun P., Bastianelli D., Lebas F., 2016. Gum arabic tree (Acacia senegal). Feedipedia, a programme by INRAE, CIRAD, AFZ and FAO. https://feedipedia.org/node/342 Last updated on December 20, 2016, 15:14

English correction by Tim Smith (Animal Science consultant)

Image credits

Sponsored by

Automatic translation

Feed categories

Scientific names

Tools

Resources

Gum arabic tree (Acacia senegal)