IJERD – International Journal of Environmental and Rural Development (2020) 11-1

Research article
erd

Effects of Different Percentages of Sorghum Silage andNapier Grass on Nutrient Intake and Growth Performanceof Goats
EI EI WIN MUANG*
Department of Animal Science, Yezin Agricultural University, Nay Pyi Taw, Myanmar
Email: eieiwinmaung@gmail.com

KHIN SAN MU
Department of Animal Science, Yezin Agricultural University, Nay Pyi Taw, Myanmar
Received 15 January 2020

Accepted 10 April 2020(*Corresponding Author)

Abstract This study was to evaluate the growth performance of goats fed different
proportions of sorghum silage and Napier grass. A total of fifteen local male goats weredivided into five groups on the basis of Completely Randomized Design (CRD). The dietary
treatments were: T1 (100% Napier grass); T2 (75% Napier grass + 25% sorghum silage), T3(50% Napier grass + 50% sorghum silage); T4 (25% Napier grass + 75% sorghum silage);
and T5 (100% sorghum silage).The experiment ran for 98 days. The average daily nutrient
intake of dry matter, crude protein, organic matter, neutral detergent fibre, acid detergent
fibre and cumulative live weight gain of the goats fed on T1, T2, T3, T4 and T5 diets were notsignificantly different (p > 0.05) from each other throughout the experimental period. Basedon these results, regardless of the inclusion of Napier grass in the diet, 100% sorghum silage
could be favourable feed for local goat in Myanmar especially dry zone area where goats are
populated and sorghum is available in planting.
Keywords sorghum silage, Napier grass, feed intake, growth performance, goats

INTRODUCTION
Ruminant production is largely limited by the availability and the high cost of quality feed. Low
quality feeds are considered to be a major constraint in farm animal production. The availability of
feed significantly decreases in the dry season when natural pastures are mature and highly fibrousand has low nutritive value due to low crude protein content (Moyo et al., 2012). Silage, anaerobicallyfermented green fodder, is widely valued as a source of animal feed. The primary goal of silage
making is to maximize the preservation of original nutrients in the forage crop for later food forlivestock (Stewart, 2011). Thus, surplus and cultivated quality forage is conserved during the wet
season for use during the dry season. Kung and Shaver (2001) reported that corn silage can be used
not only as a main source of feed for cattle but also in combination with other forage types, including
pasture grass. Silage, which is anaerobically fermented green fodder, is valued throughout the world
as a source of animal feed. Thus, feeding of ruminants with conserved forage has become an
important feeding strategy since this can be made available throughout the year. Napier grass(Pennisetum purpureum) is recommended as a basal forage for intensive cattle production becauseof its high biomass fresh dry matter yield of 40 t/ha compared to other grasses (ILRI 2001).Tesfaye
et al. (2016) observed that 100% Pennisetum purpureum silage had better feeding value as comparedto the natural grass hay fed ad libitum in crossbred lactating dairy cows. In Myanmar, locallyavailable crop residues such as rice straw, sorghum stover, maize stover, groundnut straw and pigeon
pea residues, sesame residues, butter bean residues, chick pea residues are used as feed resources forruminant in central dry zone area (CDZ) (Min Aung et al., 2015; Soe Min Thein et al., 2016). Amongthese crop residues, sorghum stover is used as common based feed mixture for ruminant becausesorghum stover production is higher than other crop residues. The dry sorghum stover production
was 800-3200kg/acre depend on soil type and nutrient quality in CDZ area of Myanmar. Farmers inⒸ ISERD

75

IJERD – International Journal of Environmental and Rural Development (2020) 11-1

CDZ area used three types of dried chopped sorghum stover based diets (50%, 60% and 70% dry
chopped sorghum stover) (Soe Min Thein et al., 2016). Feeding value and animal performance ofsorghum stover based diets were lower than that of Mombasa grass based diets because of low crude
protein contents and high fiber contents (Soe Min Thein et al., 2019). Nowadays, the farmers in dry
zone of Myanmar grew sorghum, which were fed to ruminant animals as both fresh and dry feed
mixture (Soe Min Thein et al., 2014). There is still need to do research related to effective usage offresh forage sorghum and sorghum silage for ruminant animal. There is a little information
concerning with the effects on different percentage of sorghum silage on growth performance ingoats.
OBJECTIVESThis study was undertaken to determine feed intake and growth performance of goats fed different
proportions of sorghum silage to Napier grass.
METHODOLOGY
Preparation of Napier Grass and Sorghum Silage
The sorghum forage and Napier grass were planted at the same time in the research field at Yezin
Agricultural University. The sorghum was harvested at the stage of maturity around 60 days.
Harvested and wilted green sorghum was cut into approximately 2-4 cm pieces, using a chaff cutter
machine. The chopped green sorghum chaff was compacted in the pit silo. After filling the pit silowith sorghum chaff, it was tightly covered with plastic covers and weighted down with sand bags tokeep the pit silo watertight and airtight. The silage remained sealed and in the pit silo, except to takefood once daily for the goats. The Napier grass was harvested after 90 days. This was then cut into
pieces around 2-4 cm by the chaff cutter machine and air-dried at room temperature until constantweight was obtained.
Experimental Animals and Diets
The experiment was carried out from April 2018 to August 2018 at the goat farm of Animal Science
Department, Yezin Agricultural University. A total of fifteen (locally bred) male goats at a similar
age of around six months and with weights ranging from12 kg to18 kg, were purchased from
Myanmar C.P Livestock Production Co. Ltd. These animals were randomly assigned into fivetreatment groups, with three goats each group. Initially, Ivermectin was administered by subcutaneous
injection to prevent internal and external parasites. The five treatment groups were based on thevarious proportions of Napier grass (G) and whole sorghum silage (SS): T1 (100% G); T2 (75% G +25% SS), T3 (50% G + 50% SS); T4 (25% G + 75% SS); and T5 (100% SS). The length of the feeding
trial to determine the relationship between feed intake and growth performance was 84 days, with an
initial adaptation period which lasted 2 weeks, in which no data was collected. The goats were fed
with the treatment diets ad libitum, with feed replenished twice daily, at 08:00 am and 4:00 pm.
Water was accessed freely by the animals. Feeding and drinking buckets were cleaned every morning
to prevent contamination with detrimental microorganisms such as yeasts, moulds and the spread ofundesirable bacteria that could have formed on the silage. During the feeding trial, the body weight(BW) of each goat was measured weekly, before that morning’s feed was offered.
Chemical Analysis
The chemical analysis determined the value of dry matter (DM), organic matter (OM) and crude
protein (CP) by the AOAC (1990) method. The levels of neutral detergent fibre (NDF) and aciddetergent fibre (ADF) were determined as outlined in Goering and Van Soest (1970). The feedⒸ ISERD

76

IJERD – International Journal of Environmental and Rural Development (2020) 11-1

samples were analyzed at the Department of Physiology and Biochemistry, University of Veterinary
Science, Yezin, Nay Pyi Taw.
Statistical Analysis
The chemical composition of Napier grass and sorghum silage were analyzed by Students’ t test. The
data were subjected to the one-way analysis of variance (ANOVA) using SPSS software (version 16,
SPSS Inc, Chicago. USA). Mean values were compared by Duncan’s Multiple Range Test (DMRT).
If P<0.05, the differences were considered as significance.
RESULTSThe chemical compositions of feedstuffs and experimental diets used in this experiment are shownin Tables1 and 2. The dry matter content of Napier grass was significantly higher (p < 0.05) thanthose of sorghum silage. The organic matter and crude protein of sorghum silage was significantly
higher (p < 0.05) than those of Napier grass respectively. There was no statistically difference
between Napier grass and sorghum silage for ADF, NDF and Ash. The feed intake and cumulative
live weight gain of goats fed the experimental diets containing different proportions of Napier grassand sorghum silage at 84 days are shown in Tables 3 and 4. The nutrient intake of dry matter, crude
protein, organic matter, neutral detergent fibre and acid detergent fibre by goats fed T1, T2, T3, T4
and T5 diets were not significantly different (p > 0.05) within the five treatments at 84 days. The
cumulative live weight gain of goats fed the experimental diets were not significantly different (p >0.05) among the treatment groups during the experimental period.
Table 1 Chemical composition of feedstuffs (DM basis) except DM
Item
Napier grass
Sorghum silage

DM %1)
56.63*
23.39

OM (%)
88.67
91.70*CP (%)
3.49
7.56*

NDF (%)
69.48
67.73

ADF (%)
41.83
39.07

Ash (%)
11.33
8.30

1) Fresh basis
All values except DM are on DM basis. DM = dry matter, OM = organic matter, CP = crude protein, NDF = Neutral
detergent fibre, ADF = Acid detergent fibre, *Comparison within each column and p<0.05 tested by Students’ t test

Table 2 Chemical composition of experimental diets (DM basis)
Parameters
Dry matter %Organic matter %Crude protein %Neutral detergent fibre %Acid detergent fibre %
Ash %

T1
94.38
88.67
3.49
69.48
41.83
11.33

T2
76.63
89.43
4.51
69.04
41.14
10.57

T3
58.89
90.19
5.53
68.61
40.45
9.82

T4
41.14
90.94
6.54
68.17
39.76
9.06

T5
23.39
39.07
7.56
67.73
39.07
8.30

T1; Napier grass: Sorghum silage (100: 0), T2; Napier grass: Sorghum silage (75: 25), T3; Napier grass: Sorghum silage(50: 50), T4; Napier grass: Sorghum silage (75: 25), T5; Napier grass: Sorghum silage (0: 100)

Table 3 Effect of experimental diets on average daily nutrient intake at 84 days of goats
Nutrient Intakes
Dry matter intake (kg/day)
Crude protein intake (kg/day)
Organic matter intake (kg/day)
Neutral detergent fibre intake (kg/day)
Acid detergent fibre intake (kg/day)

T1
0.54
0.02
0.48
0.38
0.23

T2
0.72
0.03
0.64
0.49
0.30

All mean values are not significant different 5% level (p>0.05).

Ⓒ ISERD

77

T3
0.80
0.04
0.72
0.55
0.32

T4
0.68
0.04
0.61
0.46
0.27

T5
0.44
0.03
0.17
0.29
0.17

SEM
0.03
0.002
0.05
0.02
0.01

p (value)
1.00
0.38
0.20
0.08
1.00

IJERD – International Journal of Environmental and Rural Development (2020) 11-1

Table 4 Effect of experimental diets on cumulative live weight gain at 84 days of goats
Live Weight Changes
Initial body weight (kg)
Final body weight (kg)
Total live weight gain(kg)

T1
18.33
24.07
5.64

T2
18.33
23.97
5.74

T3
17.33
23.98
6.65

T4
18.33
24.11
6.72

T5
16.33
23.36
7.03

SEM
0.87
0.58
0.35

p (value)
0.57
0.75
0.31

All mean values are not significant different 5% level (p>0.05).

DISCUSSION
The dry matter content of the Napier grass used in this experiment was 56.63%, which is higher thanthat of 23.4 % (Khaing et al., 2015). The CP content of Napier grass was 3.49% which is a lot lower
than that of 7.3% (Rahman et al., 2013). A possible reason for these variations might be that inprevious, trials the Napier grass was harvested about 45-60 days after planting, when the grass was
about 1m high. In this experiment, the maturation stage of Napier grass was around 90 days and thewhole plant was cut. The harvesting time is, therefore, an important factor for the nutritional
management of forage such as grasses and leguminous trees. The amount of OM in the Napier grass
was 88.67% which was in the same range with the values of 89.8% (Rahman et al., 2013) .The Ashcontent of Napier grass was 11.3% which is higher than 10.2 % (Rahman et al., 2013). The NDF and
ADF contents of Napier grass were 69.48% and 41.83% respectively. In this case, for these detergent
fibres, the values were lower than those of 74.8 % and 42.6 % (Khaing et al., 2015). In respect tothe sorghum silage, the dry matter (DM) content in this study was 23.39%, which is similar to Khaing
et al. (2015) at 23.30%, while lower than that of 56.3% in the (Muhamad et al., 2018) trial. The crude
protein (CP) value of sorghum silage was 7.56% which is lower than those of 12.6% in Muhamad etal. (2018) and 8.1% (Khaing et al., 2015). The contents of NDF and ADF in sorghum silage were
67.73% and 39.07%, which is higher than those of Khaing et al. (2015) at 58.60% and 35.10%, but
lower than those of Muhamad et al. (2018) at 81.4% and 42.5% respectively. The content of organic
matter in sorghum silage was 91.70% which is higher than the 88.5% obtained by Muhamad et al.
(2018) but lower than that of 96.10% reported by Khaing et al. (2015). In the current study, Ashcontent in sorghum silage was 8.30% which is lower than that of value 11.5% (Muhamad et al.,2018).Von Keyserlink et al. (1996) reported that chemical composition and mineral content offeedstuffs are affected by many factors such as growth, maturity, species or variety, drying method,
growth environment and soil type. Similar factors would explain the variation in this experiment.
The Napier grass contained higher NDF and ADF content than the whole sorghum silage althoughother chemical parameters were relatively similar. The inclusion of increased proportions of sorghum
silage relative to Napier grass has thus contributed to a reduction in NDF and ADF contents in theexperimental diets. Intake of dry matter, crude protein, organic matter, neutral detergent fibre andacid detergent fibre by goats fed T1, T2, T3, T4 and T5 diets were not significantly different (p > 0.05)
across the five treatments at 84 days. The goats fed the T2, T3, T4 and T5 diets showed high values forthe intake of dry matter, crude protein, organic matter, neutral detergent fibre and acid detergent fibre,
than those of the goats fed the T1 diet. The increase in the DM content of the feed might be due tothe chemical composition of the whole sorghum silage. This has a lower cell wall content resulting
in increased the dry matter composition of the sorghum silage compared to Napier grass. Okoruwa
et al. (2012) reported that the fermentation process by rumen microorganisms of high fibre diets takes
longer compared to low fibre diets. Similar results were obtained by (Khaing et al., 2015). They
reported increased growth performance of goats fed diets with a higher proportion of corn silage to
Napier grass, when the various proportion of Napier grass (G) and whole corn plant silage (CS) wereas follows: 100:0 G: CS, T2/75:25 G: CS, 50:50 G: CS, 25:75 G: CS and 0:100 G: CS and this was
fed to male Boer cross goats. This is because sorghum silage contains high amounts of fermentablecarbohydrate that increase nutrient intake by animals. The diets with a greater proportion of sorghum
silage have a lower content of indigestible fibre portion due to the fermentation process involved in
the silage production, compared to a diet solely of Napier grass. In contrast, Browne et al. (2004)
stated that voluntary intake and growth performance were negatively affected by the substitution ofhigh amounts of corn silage to the basal diet of the grass silage, due to the accumulation of high levelⒸ ISERD

78

IJERD – International Journal of Environmental and Rural Development (2020) 11-1of fermentation acid which depressed the activity of cellulolytic bacteria in the rumen. However, inthe current experiment, the basal diet was not grass silage but Napier grass. Widiawati and Thalib(2009) and Kariuki et al. (2001) stated that cell wall content of Napier grass degraded slowly in therumen and was more resistant to rumen microbial fermentation. Inclusion of corn silage to the grasssilage had a positive effect on feed intake as observed by (Browne, 2000). In addition, highconcentration of lactic acid in silage may be metabolized into propionic acid by rumen microorganisms(Abedol et al., 2013). The soluble carbohydrate can be used by the animal as an energy source formaintenance and production activities (Hariadi and Santoso, 2010). The goats fed the T2, T3, T4 andT5 diets showed higher numerical values for total weight gained than the goats fed T1 diet. The results
also mirror those of Khaing et al. (2015). They reported increased growth performance of goats fed
diets with a higher proportion of corn silage to Napier grass when the various proportion of Napiergrass (G) and whole corn plant silage (CS): 100:0 G:CS, T2/75:25 G:CS, 50:50 G:CS, 25:75 G:CS
and 0:100 G:CS fed to male Boer cross goats. Generally, the diets containing a higher percentage ofsorghum silage and which had higher CP content result in higher weight gain as the animal
performance is the product of nutrient concentration, intake and digestibility of absorbed nutrients.
CONCLUSION
According to this finding, 100% sorghum silage could be fed to goats without detrimental effect on
the growth performance. Since Myanmar farmers could not access Napier grass easily, making
sorghum silage for small ruminant will be advantages for small and large scaled farmers. Family
labour would be used to keep costs for feeding. Sorghum silage could be fed to form a balanced
ration. Therefore, it can be concluded that sorghum silage is a high potential feed comparable with
Napier grass and with positive growth response when fed to small ruminants.
ACKNOWLEDGEMENTS
The present research was financially supported by “Yezin Agricultural University – Japan TechnicalCooperation Project (YAU- JICA TCP)”.
REFERENCES
Browne, E.M. 2000. Maize silage- based diets for finishing beef cattle. Ph.D. Thesis. The University of Reading,UK.
Browne, E.M., Juniper, D.T., Bryant, M.J., Beever, D.E. and Fisher, A.V. 2004. Intake, live weight gain andcarcass characteristics of beef cattle given diets based on forage maize silage harvested at different stagesof maturity. J. Anim. Sci., 79, 405-413.
Goering, H.K. and Van Soest, P.J. 1970. Forage fibre analysis. Agricultural Hand Book, No. 379. USDA,
Washinton DC, 8-12.
Hafez, Y.H., Aedo, A.A. and Khalifa, E.I. 2012. Effect of microbial inoculation of whole plant corn silage on
growth performance and carcass characteristics of Rahmani lambs. Egypt. J. Sheep and Goat Sci, 7 (2), 1729.
Hariadi, B. and Santoso, B. 2010. Evaluation of tropical plants containing tannin on in vitro methanogenesis
and fermentation parameters using rumen fluid. J. Sci. Food Agri., 90, 456-461.
International Livestock Research Institute. 2001. ILRI 2000-2001: Deciphering the code of life to benefit thepoor. ILRI, Nairobi, Kenya, 22-25.
Kariuki, J.N., Tamminga, S., Byachuiri, C.K., Gitau, G.K. and Muia, J.M.K. 2001. Intake and rumen
degradation in cattle fed Napier grass (Pennisetum purpureum) supplemented with various levels of
Desmodium intortum and Ipomoea batatas vines. Afr. J. Anim. Sci., 31 (3), 149 -157.
Khaing, K.T., Loh, T.C., Ghizan, S., Halim, R.A. and Samsudin, A.A. 2015. Feed intake, growth performanceand digestibility in goats fed whole corn plant silage and Napier grass. Mal. J. Anim. Sci., 18 (1), 87-98.
Min Aung, M., Kyawt, Y.Y., Khaing, M., San Mu, K., Htun, M.T., Oo, L.N. and Aung, A. 2015. Nutritional
evaluation of conventional feedstuffs for ruminants using in vitro gas production technique. G.J.A.S.R., 3(2), 518-523.
Moyo, B., Patrick, J.M. and Muchenje, V. 2012. Effect of supplementing crossbred goat castrates with MoringaⒸ ISERD

79

IJERD – International Journal of Environmental and Rural Development (2020) 11-1

oleifera leaves on growth performance, carcass and non-carcasss characteristics. Trop. Anim. Health Prod.,44, 801-809.
Okoruwa, M.I., Igene, F.U. and Isika, M.A. 2012. Replacement value of cassava peels with rice husk for guinea
grass in the diet of West African Dwarf (WAD) sheep. J. Agri. Sci., 4 (7), 254-261.
Rahman, M.M., Abdullah, R.B., Wan Khadijiah, W.E., Nakagawa, T. and Akashi, R. 2013. Feed intake,digestibility and growth performance of goats offered Napier grass supplemented with molasses protectedpalm kernel cake and soya waste. Asia. J. Anim. and Vet. Adv., 8 (3), 527-534.
Soe Min Thein, Aung Aung, Kyaw Naing Oo, Nang Kham Hline, Win Myint Thein, Lwin Naing Oo, Zin Min
Latt, Tu Tu Zaw Win, Jenny Hanks and Werner Stur. 2014. Assessement of feed availability for cattle,
sheep and goats in two villages in the central dry zone of Myanmar. Proceedings of 16 th AAAP Animal
Science Congress, Gadjah Mada University, Yogyakarta, Indonesia, 10th -14th November, 915-918.
Soe Min Thein, Lwin Naing Oo, Khin San Mu, Moe Thida Htun and Aung Aung. 2019. Comparison on
performance between cattles fed on locally available forages and introduced forage in central dry zone areaof Myanmar. Proceedings of Myanmar Universities’ Research Conference, University of Yangon, 24 th 25th May, 124-137.
Soe Min Thein, Lwin Naing Oo, Moe Thida Htun, Khin San Mu, Dennis Poppi and Aung Aung. 2016.
Assessment of locally available feeds and feeding practices of ruminants in two villages in dry zone.
Proceedings of the Annual Conference of Myanmar Veterinary Association, Yangon, 27th -28th December,
51-59.
SPSS. 2007. Statistical product and service solutions. SPSS for version 16.0. Chicago, Inc., Chicago. USA.
Stewart, W.M. 2011. Plant nutrition today. From Scientific Staff of the International Plant Nutrition Institute(IPNI), Norcross, Georgia.
Tesfaye, M., Mengistu, U. and Getachew, A. 2016. Effects of different proportions of Pennisetum Purpureum
silage and natural grass hay on feed utilization, milk yield and composition of crossbred dairy cows
supplemented with concentrate diet. J. Bio. Agri. and Healthcare, 6 (11), 2224-3208.
Von Keyserlingk, M.A.G., Swift, M.L., Pchala, R. and Shelford, J.A. 1996. Degradability characteristics ofdry matter and crude protein of forages in ruminants. Anim. Feed Sci. Technol., 57, 291-311.
Widiawati,Y. and Thalib, A. 2009. Comparison of fermentation kinetics (in vitro) of grass and shrub legume
leaves: The pattern of VFA concentration, estimated CH4 and microbial biomass production. Indo. J. Agri.,2 (1), 21-27.

Ⓒ ISERD80