Elephant grass as forage for ruminant animals

Muhammad Rusdy

Department of Forage Crops and Grassland Management, Faculty of Animal Science,  Hasanuddin University, Indonesia
muhrusdy79@yahoo.co.id

Abstract

The shortage of feed, particularly during the dry season is one of the major factor limiting productivity of livestock in the tropics. Napier or elephant grass (Pennisetum purpureum Schum.) shows a great potential to alleviate the problem because it is drought resistant and has high dry matter yield potential. As an attempt to generate information useful for improving the utilization of the grass, its potential and limitation are described. Its chemical composition and nutritive value as related to management and animal’s requirement are reviewed. Possible solutions to increase animal production from low quality elephant grass were also discussed.

Keywords: animal production, digestibility, Napier grass, nutritive value

Introduction

A major problem facing livestock producers in tropical countries is how to provide a proper nutrition for their animals, especially during the dry season when pasture and cereal residues are limiting in quantity and nutritional quality. Feeding animals in the dry season is a major problem as plant growth stops and the effect of inadequate feeding on livestock productivity may be serious. Underfeeding reduces animal growth and milk yield and diminishing farmer’s income, Animals become weak, more susceptible to disease and their fertility declines. In densely populated areas in Indonesia, such conditions are exacerbated by decreasing of grazing areas as caused by conversion of grassland to natural to cropland areas, industrial estate, human settlement, etc. As results, many remaining grassland areas have undergone overgrazing and livestock are forced to graze on unused or marginal lands, such as abandoned plantation estates, road sides, forest margin and river bank.. In areas with very densely human population like Java island, natural grassland is no longer available and livestock have to be fed on cultivated fodder, crop residues, agroindustrial by-product or concentrate. But because the availability of crop residues is seasonal, the scarcity of agroindustrial by-product and the high prices of concentrates, these feed resources could not expected to fulfill the feed requirement of increasing animal population. To cope with shortage of feed, many farmers in in this area rely their forage supply on high yielding and drought tolerant fodder, mainly elephant grass (Pennisetum purpureum). This grass, is by far the most cultivated grass and in Indonesia it is mainly used in cut and carry system for dairy and beef cattle feeding. The high dry matter potential, ease of propagation, cultivate and harvest are the reason for its popularity among the farmers. With decreasing grassland area for grazing and the rising demand of animal product, the use of remaining land for cultivation of high yielding forage like elephant grass for use in stall feeding system may be the best option to increase animal production in densely populated area.

Plant description

Elephant grass has been the promising and high yield grass, giving dry matter yield that surpasses most other tropical grasses, like guinea grass (Panicum maximum) and Rhodes grass (Chloris gayana) (Relwani et al 1982) and higher nutritive value compared to Brachiaria sp and Panicum sp, (Gomez at al 2011). Historically, this grass has been primarily used as animal feed, however, it has also been used to control weeds (Skerman and Riveros 1990), as mulch for erosion control (Adekalu et al 2007), source of bio-fuel (Woodart and Sollenberger 2015), is used for making thatch, windbreak and as trap plant in the management of African stemborer (Khan et al 2007).

Although it has been long and extensively used for animal production, review on elephant grass as animal nutrition for ruminant animals is limited. Most farmers lack of knowledge and guidelines on how to utilize this grass efficiently, both as sole diet or combined with other feed resources to improve animal productivity. This review attempts to present elephant grass description and dry matter yield potential, summarize its agronomic and nutritional characteristics and to discuss its role in ruminant feeding.

Elephant grass, also known as napier grass or Ugandan grass is a monocot belonging to the family Poaceae and genus Pennisetum. Pennisetum genus is very diverse consisting of a heterogeneous group of approximately 10 000 species with annual, biennial or perennial life cycle (Martel et al 1997). There are around 25 cultivars of Pennisetum grass under cultivation (Kretschemer and Pitman (2001). Many cultivars of elephant grass have been developed worldwide to suit the local conditions and there is a wide range of habits, yield potential and nutritive value.

Elephant grass is a species of perennial tropical C₄ deep-rooted bunch grass native to eastern and central Africa (Boonman 1997). It can grow from sea level up to altitude of 2000 m. When grown at altitude above 2000 m, growth and regeneration after cutting is slow and it may die due to frost (Francis 2004). It is robust, rhizomatous, tufted and has a vigorous root system, developing from nodes of its creeping stolons. The culm is coarse, and may be up to 4–7 m in height. The plant can form dense thick clumps, up to 1 m across. The leaves are flat, linear, hairy at the base, up to 100 – 120 cm long and 1 – 5 cm wide, bluish- green in color. The inflorescense is a stiff terminal bristly spike, up to 15 – 20 cm in length, yellow-brown to purplish in color. Spikelets are arranged around a hairy axis. There is little or no seed formation. When seeds are present, they are very small (Mannetje 1992; Francis 2004). Elephant grass can be propagated through seeds, however as seed production is inconsistent, collection is difficult. Alternatively, it can be propagated vegetatively by stem cuttings or stolons. After planting, elephant grass grows vigorously and can reach 4 m in 3 months (Skerman and Riveros 1990).

Dry matter yield

Elephant grass is fast growing and has a high annual productivity that depends on climatic and soil conditions. Yields ranged from 20 to 80 t/ DM/ha/year under high fertilizer input (Skerman and Riveros 1990). Vicente-Chandler et al (1959) established a world record production of 84 800 kg DM/year when it was fertilized with 897 kg N/ha per year and cut every 90 days under natural rain of some 2000 mm per year. Elephant grass requires high levels of fertilizer and a regular water supply (Mannetje 1992). On farm, dry matter yields of elephant grass from different regions average about 16 t/ha/year (Wouters 1987). With no or inadequate fertilizers, yields are on the range of 2 – 10 t DM/ha/year (Bogdan 1977). Ra et al (2012) compared the annual biomass yield of seven grass species, viz. Erianthus, johnsongrass, switchgrass, sugarcane, maize, sorghum and elephant grass grass and found elephant grass to out-yield others by a significant margin. According to Karlsson and Vasil (1985), elephant grass is the fastest growing plant in the world.

Chemical composition and nutritive value

Crude protein

The range of protein content of elephant grass varies from 4.4 to 20.4% with the mean around 12% (Table 1). This value is not too different from the report of Xie et al (2009) that crude protein of elephant grass ranged from 4 – 15%. Age at harvest is the most important factor affecting crude protein content of elephant grass (Wadi et al 2004).. As plant ages, dry matter yield increases but crude protein declines. Such a trend in crude protein content had been reported elsewhere, and it is mainly attributed to dilution of crude protein content of forage crops by rapid accumulation of cell wall carbohydrates at the advanced stage of growth (Humphreys 1991).

From the table 1, it can be shown that in general, crude protein contents from plant harvested until 8 weeks of age were above the minimum level of 7% required for optimum rumen function, but it was not sufficient to meet the minimum crude protein requirement of 15% for lactation and growth (Mc Donald et al 2002) and only could support the need of crude protein of dairy cows with moderate milk production of 10 – 12% (ARC 1984). Only one reported crude protein value attained the required stabdard (>19%),  in elephant grass harvested at 2 weeks of age as reported by Manyawu et al (2003). However, harvesting at 2 weeks of age may harm the long term sustainable regrowth of the grass. Moreover, as the protein of young grass mostly is consisting of degradable protein (Hoffman and Brehm 2015), the quantity of protein that leaves the rumen may not be sufficient to meet the productivity  needs in ruminants (moderate to high growth rates and milk yield) (Preston and Leng,1987). According to Bactawar and Hersom (2015), during certain stages of production, cattle need more protein than what is supplied by microbial protein synthesis. According to these authors, a balance of 30 – 40% of available bypass protein and 60 – 70% rumen soluble protein is needed for optimum performance in ruminants.

Cell wall constituents

The average NDF, ADF and ADL (lignin) values of elephant grass reported by some workers are around 67, 42 and 6%, respectively (Table 2).

NDF content could be used to categorize feed quality. Singh and Oosting (1992) pointed out that roughage feeds containing NDF values of less than 45% could be classified as high quality, those with values ranging from 45% to 65% as medium and those with values higher than 65% as low quality. Except for reports of Tekletsadik et al (2004) and Olajumoke (2003), all NDF values were higher than 65%, even it was harvested at 30 days of regrowth. Based on the category, in most cases elephant grass can be classified as low quality. High NDF values can be a limiting factor to dry matter intake, as dry matter intake and NDF content are negatively correlated (Van Soest 1994).

Based on ADF values, elephant grass is also classified as low quality forage feed. According to Kellems and Church (2001), roughage with less than 40% ADF are categorized as high quality and those with greater than 40% as poor quality. Except for the report of Olajumoke (2003), all other reported ADF values are higher than 40%. 

Digestibility

 In elephant grass, 80% of variance of in vitro true digestibility was attributable to the effect of harvest interval (Chen et al 2006). With increasing harvest interval, NDF and ADF increases and digestibility decreases (Van Soest 1994).

Reported values of IVDMD and IVOMD (Table 3) from 35 to 77.4% and these are in agree with in vitro digestibility of most tropical grasses as reported by Stobbs and Thompson (1975). The reduction of digestibility with advanced maturity is related to higher ADL contents in the mature plant. ADL fraction is indigestible, which forms complexes with structural carbohydrates and this hinders exposure to microbial enzymatic attack.

The average values of IVOMD of around 60% are lower than the critical level of 65% required for feeds to be considered as having acceptable digestibility. Forage with IVOMD value of <65% can be classified as low quality and may result in reduced dry intake (Moore and Mott 1973). The low digestibility of mature elephant grass places it in the range where “rumen fill” would be the limiting factor to dry matter intake and animal production.

Conclusion

• Most reports in the literature indicate that, unless it is harvested at an early stage of growth (less than 6-8 weeks), the low protein level of elephant grass, the high values for cell wall constituents and the moderate levels of in vitro  DM and OM digestibility classify it a a forage of poor to moderate nutritive value. 

References

Adekalu .O, Olarunfemi I A and Osumbitan J A 2007 Grass mulching effect on infiltration, surface runoff and soil loss of three agricultural soils in Nigeria. Bioresources Technology, 98 (4) : 912 – 917.

AgangaA A, Umphile U J Baitshotlhi J C 2005 Nutrient composition of Napier grass (Pennisetum purpureum) and Napier grass silages made with different additives. 20^th International Grassland Congress.Dublin, Ireland.

Ansah T, Osafo E L K and Hansen H H 2010 Herbage yield and chemical composition of four varieties of napier grass (Pennisetum purpureum) grass harvested at three different days after planting. Agriculture and Biology Journal of North America 1 (5) : 923 – 929.

Antony S and Thomas C G 2014 Nutritive quality of hybrid napier grass cultivars grown under rainfed ecosystems. Journal of Tropical.Agriculture. 52 (1) : 90 – 93.

ARC 1984 The Nutrient Requirement of Ruminant Livestock. Supplement No. 1 (Commonwealth Agricultural Bureaux: Faraham Royal, UK). ARC, 1984.Agricultural Research Council.The Nutrient Requirements of Ruminant Livestock. Commonwealth Agricultural Bureaux, Farnham Royal, UK.

Bactawar, B and Hersom M 2015 Protein Requirement in Beef Cattle Rations. Retrieved on 11 November 2015 from www.union-ifas.ufl.edu/documents/ Protein Requirements in Beef Cattle Rations.pdf

Bayble T, Melaku S and Prasad N K 2007 Effects of cutting dates on nutritive value of Napier (Pennisetum purpureum) grass planted sole and in association with Desmodium ( Desmodium intortum) or Lablab (Lablab purpureus). Livestock Research for. Rural Development, 19 (1) : 27

Bogdan A V 1977 Tropical Pasture and Fodder Plants, Longman, 475 pp.

Boonman J G 1997 Farmers success with tropical grasses: Crop/pastures rotation in mixed farming in East Africa. Ministry of Foreign Affairs, TheHaque, Netherlands, p. 95.

Chen C S, Wang S M and Hsu J T 2006 Factors affecting in vitro true digestibility of Napiergrass. Asian Australasian Journal of Animal Science, 19 (4) : 507 – 513..

Francis J K 2004 Pennisetum purpureum Schumacher. In: Francis, J.K. (Ed.). Wildland shrub of the United States and its Territories: thamnic descriptions: volume 1. Gen. Tech. Rep. IITF-GTR-26. USDA Forest Service, International Institute of Tropical Forestry, 830 p.

Gomez R O, Gallegos E C, Rodriguez J J, Hernandes R E, Zavaleta E O and de la Mora, B V. 2011 Nutritive quality of grasses during the rainy season in a hot-humid climate and ultisol soil. Tropical and Subtropical .Ecosystem, 13 (20) : 481 – 489.

Halim R A, Shampazuraini S and Idrus A B 2013 Yield and nutritive quality of nine Napier grass varieties in Malaysia. Malaysian.Journal of Animal Science, 16 (2) : 37 – 44.

Hoffman P C and Brehm N M 2015 Variability of bypass protein in forages. Retrieved on 20 November 2015 from www.uwx-edu/ces/forage/ufc/hoffman.htm

Humphreys L R 1991 . Tropical Pasture U]tilization. Cambridge Uiversity Press, Great Britain.

Karlsson S B and Vasil I K 1985 Growth, cytology and flow cytometry of embriogenic cell suspension cultures of Panicum maximum Jack.and Pennisetum purpureum Schumach plant. Bulletin of the Institute of Tropical Agriculture, Kyushu University, 28 : 15 – 20.

Kellems R O and Church D C 1998 Livestock Feeds and Feeding (4^th edition). Prentice-Hall Inc., New Yersey, USA, pp.537.

Khan Z R, Midega C A O, Wadhams L J, Pickett J A and Mumuni A 2007 Evaluation of Napier grass (Pennisetum purpureum) varieties for use as trap plants for the management of stemborer (Busseolabusca) in a push-pull strategy. Entomology Experimental Application, 124 (2) : 201 – 211

Kretschemer E A and Pitman W D 2001 Germplasm resources of tropical for agegrasses. In: Sotomoyor-Rios, A and Pitman, W.D. ((eds). Tropical Forage Plant: Development and Use. CRC Press, Gainesville, Florida, pp. 27 – 40.

Koster H H, Meissner H H and Coertze R J 1999 Variation in production and quality of bana grass over the growing season using hand-clipped sample. South Africa Journal of Animal Science. 22 (1) : 31 – 34.

Lounglawan P, Longlawan W and Sulesombat 2013 Effect of cutting interval and cutting height on yield and chemical composition of King Napier grass (Penisetum purpureum x Pennisetum americanum). APCBEE Procedia, 8 : 27 - 31

MannetjeL’ t 1992 Pennisetum purpureum Schumach: Record from Proseabase. Mannetje L t and R.M. Jones (Editors).PROSEA (Plant Resources of South-East Asia) Foundation, Bogor, Indonesia.

Manyawu G J, Chakoma C, Sibanda S, Mutisi C and Chakoma L C 2003 The effect of harvesting interval on yield and nutritive value of Napier grass and hybrid Pennisetums. Asian-Austalasian.Journal of Animal Science, 16 (7) : 996 – 102.

Martel E, De Nay D, Sljk-Yokovlev S, Brown S and Sarr A 1997 Genome size variation and basic chromosome number in pearl millet and fourteen related Pennisetum species. The Journal of Heredity, 88 : 139 – 143.

McDonald P, Edwards P A, Greenhalgh J F D and Morgan C A 2002 Animal Nutrition, Six edition. Pearson Education Limited, Prentice Hall, England.

Mlay P S, Pereka A, Phiri E C, Igusti J, Hvelphlund T, Wisbjerg M R and Madsen J 2006 Feed value of selected tropical grasses, legumes and concentrates. Veterinarski Arhives, 76 : 53 – 61.

Moore J E and Mott GO 1973 Structural inhibitors of quality in tropical grasses. In: Matches (edition). Anti-quality Components of Forages.CSSA Special publication, No.4. Madison, Wisconsin, 53 – 98. \

Mtengeti E J, Lymo B J and Urio N A 2004 Effects of additives and storage position on in-bag silage quality under smallholder farmer conditions in Mvomero district Tanzania. Livestock Research for Rural Development,, 25 (11).

Mwangi D M, Cadish G, Thorpe W and GillerK E 2004 Harvesting management option for legumes intercropping with Napier grass in highlands of Kenya. Tropical Grassland, 38 : 234 – 244.

Njoka-Njiru E , Njarui M G, Abdulrazak S , Mureithi 2006 Effect intercropping herbaceous legume on dry matter yield and nutritive value of the feedstuffs in semi arid region of eastern Kenya. AgriculturaTropica et Subtropica, 39 (4) : 255 – 262.

Olajumoke, Z 2003 Effect of age of regrowth on crude protein, acid detergent fibre and neutral detergent fibre contents of two types of Penisetum purpureum. Thesis.University of Agriculture, Abeokuta, Nigeria.

Preston T R and R A Leng 1987 Matching Ruminant Production System with Available Resources in the Tropics and Sub-Tropics. Penambul Book, Armidale, Australia.

Ra K, Shiotsu F, Abe J and Morita S 2012 . Biomass yield and nitrogen use efficiency of cellulosic energy crops for ethanol production. Biomass and Bioenergy, 37 : 330 – 334.

Rego M M T, Neiva J N M, Rego A C D, Candida M J D, Clmentino R H and Restle, J. 2010. Nutritional evaluation of elephant grass silage with byproduct of annatto, 201.RevistaBrasileira de.ZootecniaVol. 39 No. 10, Vicosa Oct. 2010. Retrieved 12 July 2015 from www.scielo.br/scielo.php?pid=S1516-35982010010000268script= sci_arttext

Relwani L L, Nakar R V and Kandal D Y 1982 Intercropping of four leucaena cultivars with three grasses. Leucaena Research Reports: 3 : 41.

Silva L L P, Cassoli L D, Junior L C R, Rodrigues A C O and Machado P F 2008. In situ degradability of corn stover and elephant grass harvested at four stages of maturity. Scientific Agriculture. (Piracicaba, Braz.), 65 (6) : 595 – 603.

Singh G P and S J Oosting 1992 A model for describing the energy value of straws. Indian Dairyman XLIV, pp. 32-327.

Skerman P J and Riveros F 1990 Tropical Grasses., FAO Rome, Italy. pp. 832.

Stobbs T H and Thompson PA C 1975 Milk production from tropical pastures. World Animal.Review.13 : 27 – 31..

Tekletsadik T, Tudsri S, Juntakool S and Prasanpanich S 2004 Effect of dry season cutting management on subsequent forage yield and quality of ruzi (Brachiaria ruziziensis) and dwarf napier ( Pennisetum purpureum L.) in Thailand. Kasetsart Journal. (Natural Science),38 : 457 – 467.

Tikam K., Mikled C, Vearasilp T, Phatsara C and Sudekum K H 2010 Digestibility of nutrient and evaluation of energy of Pangola grass in sheep compared with Napier grass. Tropentag, ETH Zurich, September, 14 – 16, 2010.

Van Eys J E, Mathius I W, Pongsapan P and Johnson W L 1986. Foliage of the three legume gliciridia, leucaena, and sesbania as supplement to napiergrass diet for growing goats. Journal of Agricultural Science, 107 (2) : 227 – 233.

Van Soest P J 1994 Nutritional Ecology of the Ruminant.Comstock Publishing Associates.A division of Cornell University Press, Itacha and London.

Vicente-Chandler J, Silva S and Figarella J 1959 The effect of nitrogen fertilization and frequency of cutting on the yield and composition of three tropical grasses. Agronomy.Journal, 51 : 202 – 206.

Wadi A, Ishii Y and Idota S 2004 Effect of cutting interval and cutting height and dry matter yield and overwintering ability at the established year in Pennisetum species. Plant Production Science,7 : 88 – 96.

Wijitphan S, Lorwilai P and Arkaseang C 2009 Effects of cutting height on productivity and quality of King Napier grass (Pennisetum purpureum cv King Grass) under irrigation. Pakistan.Journal of. Nutrition,8 : 1244 – 1250.

Woodart K R. and Sollenberger L N 2015 Production of biofuel crops in Florida: Elephantgrass. IFAS Extension, University of Florida. Retrieved July 1, 2015 from https://edis.ifas. ulf.edu//pdffiles/AG//AG30200.pdf

Wouters A P 1987 Dry matter yield and quality of Napier grass as affected by harvesting frequency and genotype. Agronomy Journal. 83 : 541 – 546.

Xie X M, Zhou F, Zhang X Q and Zhang J M 2009 Genetic variability and relationship between MT-1 elephant grass and closely related cultivars assessed by SRAP markers. Journal of .Genetics. 88: 281 – 290.

Received 4 September 2015; Accepted 18 March 2016; Published 1 April 2016

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