ABSTRACT

Methods of silage making using various kinds of raw materials have been studied at government research stations and transferred to farmers, mostly in dairy farms. Ensiling in black plastic bag is the only method widely used in dairy farms more than any other methods, because of its convenience for filling, packing, sealing, handling and feeding out. However, farmers have the difficulty of adopting silage making in as part of their farm activity. Other studies in government research institution have been done in order to improve the quality of silage by using legume species and biological additives.

INTRODUCTION

The livestock industry in Thailand is composed of beef cattle, dairy cattle, buffalo, goat and sheep with a population of 4,635,741, 282,655, 79,960, 125, 2662 and 41,926 heads respectively (Planning Division 1999). Roughages from communal and private area are the main feed for livestock. About 4,942, 042 rai of communal grazing   land and accordingly 1,895,597 ha of private land are considered inadequate for all livestock throughout the year. (Planning Division 1999)

The shortage of feed in terms of quality and quantity, especially during dry season, is one of the most serious problems faced by farmers’ in Thailand for the further development of its cattle industry.  To overcome feed shortage during dry season, by-products from agriculture and other industries are usually feed to cattle in the form of roughage or concentrate feed. Use of preserved surplus of various kinds of raw materials, such as fresh grasses and residues in the form of silage are fed to cattle in dry season. Many methods of silage making have been studied at government research stations and transferred to farmers in order to improve silage making method for cattle farmers.

Silage making methods used by government and dairy farms
The Animal Nutrition Research Center and the Animal Nutrition Station of Thailand undertake silage making as a form of their fodder conservation. This activity has been done for many years now.  In Thailand, Ruzi, Purple guinea, Atratum and Sorghum are used as materials for silage making. However, corn stover (after harvesting baby corn or sweet corn) is the most suitable by-product for silage making.

 In Thailand, silage has been produced in several methods, enumerated below:

1. Concrete bunker silos. These are built at dairy farms and government research station with varying sizes. Concrete bunker silo in dairy farms in Ratchaburi and Phrae provinces is 145 cm. wide, 450 cm. long and 115 cm. high with 5 tons capacity.
2. Concrete trench silos. Built in dairy farm in Petchaburi province with a capacity of 150 tons.
3. Trench silos without concrete frame are built at Trang Animal Nutrition Station and Petchaburi Animal Nutrition Research Center. Their capacity varies from 20 to 120 tons.
4. Plastic stack silos are usually set up on solid or concrete floor. A large plastic stack silos (about 35 m long x 7 m wide x 2.5 m high) with thicker plastic sheets are made at Chiengmai Livestock Research and Breeding Center, and its capacity is 200 to 250 tons.
5. Paper tuber silos. These are the by-products of a food processing company and are widely used as silo in dairy farms at Ratchaburi province. Each tube has a capacity of 100 kg.
6. Small round-baled wrapped silo is made at many sites of Animal Nutrition Research Center, its capacity is 50 kg.
7. Silage in black plastic bag is widely used at small dairy farms in Thailand. Its capacity is 40 to 50 kg.
8. Silage in jumbo bag is used at small dairy farms in Ratchaburi and Petchaburi provinces. Its capacity is 600 to 800 kg.

Adoption of silage making

Animal Nutrition Research Centers and the Animal Nutrition Stations in Thailand collaborated with a district livestock officer conduct demonstration on the methods of silages making demonstration in about 600 dairy farms last year. Most silage in Thailand is made from grasses such as Ruzi grass, Purple guinea grass and Napier grass. But most dairy farms at Ratchaburi, Kanchanaburi and Nakornpathom provinces used only corn stover for silage from months of October to January.

Widely used method of silage making for small farms
Monitoring and evaluation of silage demonstration at dairy farms showed that ensiling in black plastic bags is widely used in small dairy farms. This is because they are very much convenient for filling, packing, sealing, handling and feeding out. The advantages of black plastic bag are as follows:

1. Cheap and easy to make silage
2. Small quantity of forages are required
3. Less labor required which is suitable for small farmers

Commercial corn silage in Nakornrachasrima province
Three farmers in Pakchong district, Nakornrachasima province produced corn silage in 20 kg. bag for sale. The selling price is about 30 baht/bag. Each farmer can produced and sell 90 tons of silage per month. This silage in plastic bag is made from whole corn plant and has been sold to dairy farms in Pakchong district and nearby area.

Most dairy farmers don’t adopt silage making in concrete bunker, trench silos, and plastic stack and in jumbo bag.

The reasons are:

1. Lack of fresh grasses for silage making because most of dairy farmers have a small area for pasture establishment.
2. Lack of investment capital for the purchase of materials and machine for silage making.
3. The lack of time among farmers and insufficient family labor for making silage.
4. Small quantity of silage production is not enough for many dairy cows during dry season.
5. Some materials such as big columnar plastic bag and black plastic bag are difficult to buy in market.
6. During dry season, dairy farmers have enough agriculture by-products such as rice straw, corn stover and pineapple waste for dairy cows.

Silage technique development

Use of cassava chips as  additive to Desmanthus legume (Desmanthus virgathus) ensilage
This experiment took place at Chainat Animal Nutrition Research Center wherein a study to compare the nutritive value and fermentative quality of silages prepared directly from fresh Desmanthus legume alone or in combination with the addition of 0, 3, 6, 9, 12 and 15% of cassava chip on dry matter basis.

The Desmanthus legume harvested at 60 days interval was collected and chopped into 2-cm. lengths and mixed with different level of cassava chip. The chopped Desmanthus was directly packed in a black plastic bag. The weight of a bag with legume is 20 kg. and kept in storage for the duration of the study. The ensiled materials were opened after 30 days and samples were analyzed for Dry matter (D.M.), pH, lactic acid, acetic acid and butyric acid tests.

The chemical composition (dry matter, crude protein and water soluble carbohydrate) of Desmanthus legume was at 31.20, 23.40 and 6.79% respectively. The level of DM and WSC is suitable for silage making. Cassava chip that is used as additive consists with 93% of dry matter, 2.84% of crude protein and 3.03% of water-soluble carbohydrate, (Table 1) The result as shown in Table 2 indicates that the fermentation quality of all silage were good. The quality of silage without cassava chip was as good as that with cassava. Visual and sensory evaluation of the silage also produced good result.  No significant difference was observed in pH value, lactic acid and Butyric acid between the silages. All the silages differ significantly (p < 0.05) in. DM content, total N, true protein, acetic acid and WSC.

It was concluded that the addition of cassava chip did not make any change in the characteristics of the fermented silage but rather increased its DM levels.

Ensiling Desmanthus without additive gave well-preserved silage. This is probably due to the high levels of water-soluble carbohydrates (6.79%).

Table 1. Chemical composition of Desmanthus virgathus and cassava chip

	Dry matter (%)	% of dry matter
		Protein	WSC
Desmanthus Cassava chip	31.20 93.00	23.40 2.84	6.79 3.03

 Source: Animal Nutrition Laboratory Section, 1998     

	PH	DM. %	% of  DM.
			Total N	True Prot.	Lactic Acid	Acetic Acid	Butyric Acid	WSC.
Desmanthus	5.27a	30.02b	4.12a	13.24a	3.40a	2.02b	0.57a	0.83c
Desmanthus  +   cassava chip (3%)	5.14 a	30.63 cd	3.57 b	11.16 b	2.87 a	2.34 b	0.64 a	0.81 c
Desmanthus +       cassava chip (6%)	4.84 a	32.59 bc	3.26 bc	9.81 bc	2.64 a	2.70 a	0.59 a	1.16 b
Desmanthus +     cassava chip (9%)	5.06 a	32.81 bc	2.99 cd	10.98 bc	2.65 a	2.20 b	0.68 a	1.59 a
Desmanthus +   cassava chip (12%)	4.94 a	34.93 b	2.98 cd	8.88 cd	2.77 a	2.28 b	0.62 a	1.65 a
Desmanthus +   cassava chip (15%)	4.83 a	38.14 a	2.59 d	7.66 d	2.87 a	1.96 b	0.60 a	1.26 b

CONCLUSION

In Thailand, many methods of silage making from various kinds of raw materials have been studied at government research station and transferred to most dairy farms. Observation showed that adoption of silage making in small farmers are still low.

Ensiling in black plastic bag is only one method which is widely used in dairy farms, because of its convenience for filling, packing, sealing, handling and feeding out. The farmers in Pakchong district, Nakornratchasrima province produced corn silage for sale at size of 20 kg. of black plastic bag which its selling price about 30 baht/bag or 1.50 baht/kg. However, silage making from legume species have been studied by researcher in order to improved quality of silage such as the study in the use of cassava chip as an additive to Desmanthus legume. The results showed that ensiled Desmanthus  (cut  at  60  days)  without additive gave good preserved silage due to its high levels of water-soluble carbohydrates.

REFERENCES

Animal Nutrition Laboratory Section. 1998. Table of Chemical composition of pasture species. Animal Nutrition Laboratory Section. Animal Nutrition Division, Department of Livestock Development, Ministry of Agriculture and Cooperatives. Thailand, 17 p.

Panichapon, Warunee. 2001. Use of cassava chip as an additive to Desmanthus virgathus ensilage. Thai Forages Newsletter. April- May 2000.

Planning Division. 1999. Yearly Statistics Report 1999. Planning Division, Department of Livestock Development, Ministry of Agriculture and Cooperatives. Thailand, 191 pp.