Chemical composition and in vitro gas production of lesser known South Sudan browse species

M T Deng¹, J O Ondiek and P A Onjoro

Department of Animal Science, Egerton University, P.O. Box 536, Njoro, Kenya
mamerjohn99@gmail.com
¹ Department of Animal Production, Dr. John Garang Memorial University of Science and Technology, Bor, South Sudan

Abstract

The aim of this study was to evaluate the nutritive value of the selected South Sudan browse species namely, Grewia tenax, Balanites aegyptiaca, Cordia sinensis, Tamarindus indica, Ziziphus spina_christiand Kedrostis foetissima to fill feed nutrient deficiency gap in the area. Forages were analysed for chemical composition including polyphenolics, minerals and in vitro gas production characteristics.

Among the browse species, G. tenax had the highest crude protein value while the lowest value was recorded in T. indica. C. sinensis had the highest NDF and ADF contents while B. aegyptiaca and G. tenax had the lowest NDF and ADF contents, respectively. T. indica was observed to be highest in condensed tannin ((≥60g/kg). Mineral concentrations varied among species with enough quantities except manganese (Mn) which was deficient in C. sinensis. At 24hour, the highly digestible fraction was similar among the species however, Z. spina-christi had the highest gas production. It is concluded that, all the browse species have great potential to fill the feed protein gap and thus could be good protein supplements to poor quality roughages in the area.

Key words: Cordia sinensis, dried leaves, Grewia tenax, Kedrostis foetissima, nutrient deficiency

Introduction

The rearing of livestock plays an important role in enabling smallholders to have resilient livelihoods and to avoid both food insecurity and poverty. Randolph et al (2007) reported that livestock contributed one-third of the protein that people consumed that is necessary for thinking and physical development. However, during critical periods, these animals hardly meet their high potential production (milk or meat) due to poor and inadequate quality of feed causing nutrient deficiency (Elis 1982; Fadel Elseed et al 2002). Moreover, the conventional feed resources such as grains, cereals, legumes, grass hay and their residues are scarce and expensive. It will be worth persisting with the ways to improve use of locally available feed resources especially tree and shrub forages in the wild. B. aegyptiaca and Z. spina-christi crude protein could be adequate to meet the late dry season requirements of small ruminants (Lazim 2007). Tamarind trees growing in woodlands are often most preferred plant by wild ruminants, such as elephants or giraffe, perhaps because of its high crude protein content (El-Sidig et al 2006). K. foetissima (jacq.).Cogn despite its unpleasant smell, cattle have been seen in the study area feeding on it ravenously and is belief by the herds-men to increase milk production in lactating cows. Furthermore, Grewia species fruits help in treating anaemia (Mohammed et al 2010) besides being livestock forage. Therefore, the main objective of this study is to assess the potential nutritive value of the above mentioned native species from South Sudan rangeland based on chemical composition, mineral concentrations and in vitro digestibility.

Material and methods

Forages collection and preparation

The selected six browse forages because of their availability throughout the year used in this study include:G. tenax, T. indica, B. aegyptiaca, Z. spina_christi, C. sinensis and K. Foetidissima. All forages were harvested from Bor’s rangeland in South Sudan from late November to April. The area is located at an altitude of 407 m above sea level with average annual rainfall and temperature of 891 mm and 27.3 ^oC, respectively. The leaves of these species were harvested separately by hand picking. In each collection day, the harvested samples were then pooled for each individual tree species and then air dried in a well-ventilated room to constant weight and ground to pass through a 4 mm sieve. However, for laboratory analysis, the forages were further ground to pass through a 1.0 mm sieve and then sub-sampled to obtain three samples for each tree species.

Nutrient composition analysis

Proximate fractions, including DM, ash, OM, EE total N in feed was determined following standard methods (AOAC, 1990). CP was obtained by multiplying N in feeds by the factor (6.25). NDF and ADF were determine according to ANKOM²⁰⁰ fibre analyser operator`s manual (2014). The extraction of phenolic was carried out by using 70% aqueous acetone. TEPH were determined using Folin Ciocalteu procedures as described by Julkunen- Titto (1985) and Evitayani et al (2004). The CT were measured and calculated as leucocyanidin equivalent, following the method of Porter et al (1986). Macro and micro-elements were analysed using atomic absorption spectrophotometer.

In vitro gas production

The browse samples were incubated in vitro with rumen fluid in calibrated glass syringes following the procedure of Menke and Steingass (1988). Rumen liquor was obtained from three male goats through suction tube before morning feeding. Normally feeding was with Rhode grass and 200g DM browse each after a 14day adaptation period with free access to water and mineral lick. About 0.2g of 1 mm milled samples were weighed into 100 ml calibrated glass syringes in triplicates. About 30 ml of rumen-buffer mixture was added into each syringe and then all the syringes were incubated in a water bath maintained at 39^oC. The syringes were gently shaken every hour during the first 8 hours of incubation. Readings were recorded after 3, 6, 12, 24, 48, 72 and 96 hours. The mean gas volume readings were fitted according to Ørskov et al (1979) model using Neway` computer program (X.B.Chen, Rowett Research Institute, Aberdeen).

Statistical analysis

The data collected were analysed using Analysis of Variance (ANOVA) following General Linear Model procedure of Statistical Analysis System (SAS version 9.0 2002). Significant differences among the means was tested and adjusted using a multiple comparisons: Turkey at P<0.05) difference.

Results

Chemical composition of the forages

The nutrient composition of browse forages is presented in Table 1. The observed high CP (Figure 1) content of the browse species justifies their use as supplement to poor quality natural pastures. The concentration of CT ranged between (3-38 g/kg) which is of nutritional benefits to ruminants. T. indica, however had CT (≥60g/kg) which is detrimental (Figure 2).

Figure 1. The crude protein levels of the selected South Sudan browse species

Figure 2. The condensed tannin contents of the selected South Sudan browse species

Macro and micro mineral concentration of browse forages

Mineral concentration among the species are presented in Table 2. From all the species B. aegyptiaca was outstandingly high in Ca, Fe, Co and Mn. K. foetidissima, G. tenax and Z. spina_christi were abundant in P, K and Na respectively whereas T. indica was high in Mg and Cu. However, among the species Zn concentration was exceptionally higher in C. sinensis, but with Mn deficiency  (Table 1).

In vitro gas production and fermentation parameters

Gas production and fermentation parameters are presented in Table 3. At 24 and 48h, T. indica produced the lowest gas volume while in potential gas production the highest and the lowest were recorded in Z. spina-christi and B. aegyptiaca, respectively (Figure 3). The rate of gas production was highest in Z. spina-christi and the lowest in T. indica. The in vitro gas production and fermentation parameters indicate the presence of potential degradable nutrient in browse species which underscores the importance of these indigenous browse species as source of nutrition for ruminant animals.

Figure 3. The gas production after 24h from the selected South Sudan browse species

Discussion

Crude protein contents for the most of species were consistent with values reported by (Welay et al 2011; Balehegn et al 2015 and Elseed et al 2015) for B. aegyptiaca and Z. spina_christi and for other species in the tropical region rangelands. NDF and ADF characteristic values were consistent to the values reported by (Singh and Oosting 1992; Bakshi 2007). The CT and TEPH agrees with the values reported by (Welay et al 2011; Balehegn et al 2015 and Elseed et al 2015). The mineral contents for T. indica were consistent to the work reported by (Nordeide et al 1996; El_siddig et al 2006; De Caluwe et al 2010) except Zn whereas, G. tenax, B. aegyptiaca and Z. spina_christi mineral contents were consistent to the work of (Rubanza et al 2007; Saleem et al 2012; Elseed et al 2015). In contrast, Kuria et al (2004) reported higher (Na, Fe, K, Ca) and lower Cu, Zn) contents in C. sinensis and lower Cu, Zn, K, and Na in G. tenax and B. aegyptiaca. The high extent of gas production in Z. spina-christi might be due to high OM availability which was fermented to form volatile fatty acids and therefore high gas volumes was produced. The observed low gas production in T. indica might be due to its high tannin content which reduces the population of fiber degrading bacteria in the rumen and hence low activity (Makkar and Becker 1996; Getachew et al 2000). B. aegyptiaca ranked the lowest in gas production potential, this trend could be due to level of tannins and other anti-nutritive factors. The highest rate of feed OM degradability observed in Z. spina-christi is probably due to presence of high fermentable carbohydrate, on the other hand, it is a reflection of microbial growth and accessibility of feed to microbial enzymes (Getachew et al 2000).

Conclusion

• The browse forages evaluated in the current study had high CP content which would make them good protein supplements to poor quality roughages especially during the dry season.
  
  
• In vitro gas production, the highest values obtained for the rate of gas production and parameters in Z. spina-christi indicate better nutrient availability for rumen microorganisms.
  
  
• In the future it is important to measure methane production of the species.

Acknowledgement

The senior author is grateful to USAID through BHEARD, (Michigan State University) for funding this work.

References

ANKOM Technology 2014 Method for determining neutral detergent fiber in feeds (ANKOM²⁰⁰ fibre analyser operator`s manual).

Bakshi M P S and Wadhwa M 2007 Tree leaves as complete feed for goat kids. Small Ruminant Research, (69): 74-78.

Balehegn M, Eik L O and Tesfay Y 2015 There is more in fodder trees than their nutritional values: local valuation of indigenous fodder trees and shrubs by pastoral and agrarian communities in northern Ethiopia. Forests, Trees and Livelihoods, 24(2): 112-127.

De Caluwe E, Halamova K and Van Damme P 2010 Tamarindus indica L. – A review of traditional uses, Phytochemistry and pharmacology. Afrika focus, 23: Nr. 53-83.

Elis N 1982 The nutrient composition of Sudanese animal feeds. Bulletin II: Southern Sudan. Kuku Research Centre, Khartoum, Sudan.

El-Siddig K, Gunasena H P M, Prasa B A, Pushpakumara D K N G, Ramana K V R, Vijayanand P and Williams J T 2006 Tamarind – Tamarindus indica L. Fruits for the future 1. Southampton Centre for Underutilized Crops, Southampton, UK, 188.

Evitayani L, Warly, Fariani A, Ichinohe T, Abdulrazak A.A and Fujihara T 2004 Comparative rumen degradability of some legume forages between wet and dry season in West Sumatra, Indonesia. Asian-Australian Journal of Animal Science. 17(8): 1107-1111.

Fadel Elseed A M A and Amin A E 2015 Nutritive Evaluation of Some Fodder Tree Species during the Dry Season in Central Sudan.

Fadel Elseed A M, Amin A, Khadiga A E, Abdel Ati A, Sekine J, Hishinuma M, and Hamana K 2002 Nutritive evaluation of some fodder tree species during the dry season in Central Sudan. Asian-Australian Journal of Animal Science, 15 (6): 844-850.

Fielding W, Gullik C, Coutts P and Sharp B 2000 An introduction to the food economy research in Southern Sudan. UK, Nairobi, Kenya.

Getachew G, Makkar H P S and Becker K 2000 Effect of Polyethylene glycol on in vitro degradability of nitrogen and microbial protein synthesis from tannin-rich browse and herbaceous legumes. British Journal of Nutrition 84: 73-83.

Kuria S G, Wahome R G, Gachuiri C K and Wanyoike M M 2004 Evaluation of forages as mineral sources for camels in Western Marsabit, Kenya. South African Journal of Animal Science, 34 (3).

Lazim A M 2007 Proximate composition of some fodder trees in the South Kordofan State. Ministry of Science and Technology Agricultural Research Corporation, Proceedings the 41 and 42 meetings of the national crop husbandry committee, Wad Medani.

Makkar H P S and Becker K 1996 A bioassay for polyphenols (tannins). Polyphenols Communications 96, July 15-18, Bordeaux, France.

Mohammed Elhassan G O and Yagi S M 2010 Nutritional composition of Grewia spp (G.tenax (Forsk.) Flori, G. flavescencs Juss and G.villosa wild) fruits. Advance Journal of Food Science and Technology, 2(3): 159-162.

Nordeide M B, Harløy A, Følling M, Lied E and Oshaug A 1996 Nutrient composition and nutritional importance of green leaves and wild food resources in an agricultural district, Koutiala, in Southern Mali.International Journal of Food Sciences and Nutrition, 47: 455-468.

Ørskov E R and McDonald I 1979 The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage. Journal of Agricultural Science, 92: 499-503.

Porter L J, Hrstich L N and Chan B G 1986 The conversion of procyanidins and prodelphinidins to cyanidin and delphinidin. Phytochemistry, 25: 223-230.

Randolph T F, Schelling E, Grace D, Nicholson C F, Leroy J L, Cole D C, Demment M W, Omore A, Zinsstag J and Ruel M 2007 Role of livestock in human nutrition and health for poverty reduction in developing countries. Journal of Animal Science, 85: 2788–2800.

Rubanza C D, Shem M N, Bakengesa S S, Ichinohe T and Fujihara T 2007 The content of protein, fibre and minerals of leaves of selected Acacia species indigenous to north-western Tanzania. Archives of animal nutrition, 61(2): 151-156.

Saleem N A, El-Nour M and Khalid A.A M 2012 The nutritive value of leaves and fruits of three grewia species under semi-arid environment. Journal of Agricultural Science and Technology, 2: 956-964.

SAS 2002 Statistical Analysis System Institute. SAS User’s Guide. Statistics, Software Version 9.00 (TS MO) SAS Institute, Inc., Cary, NC, USA.

Singh G P and Oosting S J 1992 A model describing the energy value of straw.Indian Dairyman XLIV: 322-327.

Welay K 2011 Livestock production status, traditional utilization and chemical composition of major browse species in rangelands of Mieso district, Ethiopia.

Received 23 December 2016; Accepted 11 February 2017; Published 1 April 2017

Go to top