Livestock Feeds

Feed Classification

All Feeds

Roughage

Concentrate Feed

Unconventional Feed

Napier grass

Common names: Giant grass, Elephant grass, Merker grass, Uganda grass, Bana grass, Barner grass

Scientific Name: Pennisetum purpureum

Feed categories: Green roughages-cultivated fodder

Physical Characteristics:

Napier grass forms dense, thick clumps up to 1 m across. The leaves are flat, linear and hairy at the base, up to 100-120 cm long and 1-5 cm wide, with a bluish-green colour. The leaf margin is finely toothed and the leaf blade has a prominent midrib.

Production / Availability:

Napier grass is a perennial C4 grass species native to around the world and monocotyledonous flowering plant and possesses a number of attributes including; high biomass yields, rapid re-growth potential and ease of propagation. Many varieties of Napier or elephant grass have been developed worldwide due to its desirable traits such as tolerance to drought and a wide range of soil conditions, and high photosynthetic and water-use efficiency (Anderson et al., 2008). Napier grass is one of the highest yielding tropical grasses. It commonly distributed and propagates by vegetative (stem) cuttings and tillers. Stem contain at least two nodes, one is buried in rows at 45⁰ angle another node is open in air currently the foremost practice for Napier grass propagation. Generally, line to line distance is 70 cm to 75 cm and plant to plant distance is 25 to 30 cm for planting. Napier grass cultivation has recently acquired a great popularity in Bangladesh as livestock fodder. The fodder is cultivated from March to end of October in Bangladesh. Napier grass flourishes in a warm and humid area and requires clay to clay loam soil in order to achieve optimal growth. The initial harvest is completed within 65-70 days of achieving a high biomass yield, while following harvests occur every 30-40 days. The yield of Napier grass is influenced by factors such as agronomy practices, the age and height of the plant at the time of harvest, and the characteristics of the soil. By adhering to these agronomical practices, the harvest took place 7 to 8 times annually. Napier grass is mostly utilized in cut-and-carry systems, commonly known as "zero grazing," where it is harvested and fed to animals in stalls, or alternatively, it can be processed into silage.

Napier is known as high yielding fodder variety throughout the world. The Bangladesh Livestock Research Institute (BLRI) is currently preserving eleven Napier cultivars at the Pachutia fodder germplasm Bank. These cultivars include BLRI Napier-1, BLRI Napier-2, BLRI Napier-3, BLRI Napier-4, Murkeronk, Rokona, Dwarf Early, Dwarf Late, Pakchong, Red Pakchong, and Zara. Among them, BLRI Napier 1 to 4, which has been developed by BLRI. BLRI improved yield of Napier cultivar from 150 to 160 ton per hectare to 220 to 280 ton per hectare/year. Small farmers and commercial dairy and fattening farmers are cultivated these high yielding fodders throughout the country. In many parts of the country, farmers are producing Napier fodder on a commercial scale and selling it in the market. Research data and farmers opinions showed that Napier cultivation is more profitable than rice cultivation. Napier grass is widely utilised as a feed option in smallholder dairy farms in Bangladesh. Farmers do not get the proper nutritional value of the Napier fodder due to lack of knowledge on nutrient composition and harvesting of Napier fodder at field level. Additionally, BLRI has devised a Napier cultivar that is resistant to both salt and drought, specifically designed for cultivation in coastal and draught areas. The use of gamma radiation technology facilitated the development of the Napier fodder cultivers, which exhibits resistance to both salt and drought conditions. The cultivar is capable of thriving in soil with a salinity level of up to 12 dsm /sqm².

In 2018, BLRI initiated a research project on enhancing the quality and quantity of Napier grass with the technical support of the University of Sydney, Australia. This research was concerned with the grass's plant density and height while remaining at the cutting edge of management techniques. Based on this research, BLRI has already developed Best Management Practices (BMP) for Napier grass, which contained 18–20% crude protein (CP) and 9-10 MJ ME/kg DM. Without concentrate, BMP Napier grass will meet the nutritional requirements of dairy and beef animals. By implementing this Napier management technique, feed expenses for producing meat and milk will be reduced by 20–30%.

Nutrient Composition

Main analysis	Unit	Avg	SD	Min	Max	Nb
Dry Matter	% as fed	19.54	6.78	11.32	37.02	33
Crude protein	% DM	10.63	2.79	5.17	16.83	43
Crude Fibre	% DM	30.91	5.2	44.43	43.2	30
NDF	% DM	65.23	11.45	40.4	81.86	30
ADF	% DM	43.27	6.31	31.7	58	40
Lignin	% DM	6.1	1.93	3.50	10.00	7
Ether extract	% DM	2.28	0.84	1.12	3.65	22
Ash	% DM	12.94	3.82	3.89	20.48	41
Gross Energy	MJ/kg DM	17.00	1.27	15.78	19.82	9
ME (Metabolizable energy)	MJ/kg DM	6.94	1.38	5.21	9.2	10
Calcium	g/kg DM	4.71	1.94	1.1	7.78	26
Phosphorus	g/kg DM	2.98	1.1	0.7	4.7	11

NDF= Neutral Detergent Fiber; ADF= Acid Detergent Fiber.

Nutritional aspects of Napier grass

The nutritional content of Napier grass is significantly influenced by plant height, harvesting age, harvesting interval, severity height, plant density, season, variety and overall management practice (Roy et al., 2023). The concentration of dry matter (DM), Ash, acid detergent fiber (ADF) and neutral detergent fiber (NDF) in Napier grass increases when harvesting age or days increase, but the content of crude protein (CP) in Napier grass decreases as harvesting age or days grow. When harvested at 20, 24, 30, 40, 50, and 60 days, respectively, the DM content of Napier grass remains at 11.32, 12.99, 14.51, 16.07, 18.81, and 21.24%, while the CP content remains at 22.78, 20.98, 18.9, 13.99, 12.24, and 9.88% with respect to harvesting at 20, 24, 30, 40, 50, and 60 days. When Napier grass was harvested at 20, 24, 30, 40, 50, and 60 days, the ADF content was 31.71, 34.41, 34.5, 37.72, 41.74, and 42.15%, respectively. However, the NDF content was 59.19, 63.31, 65.17, 67.35, 68.4, and 69.35%, and the ash content was 7.92, 8.93, 9.6, 10.88, 11.44, and 12.77%, during the corresponding harvesting periods. In another scenes defoliation height had a significant effect on the percentage content of dry matter and organic matter in both Napier grass, with DM percent and OM percent increasing as the defoliation height increased from 50 to 200 cm (Roy et al., 2020). In that case the cutting intervals were 18-20, 28-30 and 58-60 days for 50, 100 and 200 cm defoliation heights respectively. By comparison, crude protein showed a decrease as the defoliation height increased. The crude protein content in Napier grass were 19-22, 15-17 and 10-12% respectively for plants cuts from 50, 100 and 200 cm defoliation height. For plants cut from 50, 100, and 200 cm defoliation height, the dry matter content was 13.5, 14.5, and 16.6%, respectively, while the ash content was 8.72, 8.30, and 6.10%, respectively. For plants cut from 50, 100, and 200 cm defoliation height, the ADF content increased to 32.5, 36.5, and 38.6%, respectively, while the NDF content increased to 55.0, 66.0, and 69.0%, as the defoliation height increased.

References

Roy B.K., N. Sultana and A. Roy. (2020). Maximize the yield and nutritive value of Napier grass by determining the cutting height and severity for optimal re-growth. Annual Research Review Workshop 2020, BLRI, Savar, Dhaka.

Roy B.K., N. Sultana and A. Roy. (2020). Effect of defoliation and severity height on nutrient composition of Napier Pakchong grass. Annual Research Review Workshop 2021, BLRI, Savar, Dhaka.

Roy B.K. and A. Roy. (2023). Biomass yield, morphological characteristics, nutritional values and production costs of different Napier cultivars under on-station condition: A review (personal communication).

Anderson, W.F, Dien, B.S, Brandon, S.K. and Peterson, J.D. (2008) Assessment of Bermuda Grass and Bunch Grasses as Feed Stocks for Conversion to Ethanol. Applied Biochemistry and Biotechnology, 145, 13-21.