Small polybag silage (SPBS); an adaptive technique to overcome the feed shortage of dairy animals in the dry zone.

Abstract

In Sri Lanka, rice straw, crop residues and over matured natural forages are the major roughages available for feeding dairy animals during dry season. In some South Asian countries such as India, Pakistan and Nepal silage feeding as a supplement is being practiced extensively during dry spells and farmers are compelled to produce silage in small polyethylene bags as SPBS. Its viability and economy have also been verified by these countries. This technique is absolutely novel to Sri Lanka. The objective of this adaptive study was to evaluate the technique and cost of production of SPBS under on farm conditions of small dairy holdings in the dry zone. ' Five dairy homesteads in Kekirawa, Tanamalwila, Lunugamvehera, Hambantota and Suriyawewa veterinary ranges were selected. Strong high density polythene bags to outfit a capacity of 50 kg of chopped green fodder were used for silage making. The farm grown fodder was harvested and was either hand chopped with a large knife, or chopped through a chaff cutter. Chopped green fodder in 50 kg of weight was carefully i packed into a bag with 3kg of molasses, 250g of urea and 250g of kitchen salt (NaCl) as additives. The bag was gently squeezed by hand to expel air while compressed the forage material into the bag. The bag was then inverted into second and third empty bags which was also closed and tied. A set of 5 bags (as 5 replicates) were prepared ; using same techniques and raw materials in each locations. After a minimum of 45 days period bags were opened and observed the smell and appearance of the silage matter. Cost of production - COP (labour wages for harvesting, chopping and filling of fodder, and bag cost) were also calculated. COP data were analyzed using ANOVA. Investigators observed that smell of lactic acid fermentation resulted in eveiy lot of silage at all locations and appearance (colour and texture) of silage was also similar to the typical silage quality. Cost of production including bag price varied from 4.75 to 5.25 Rs/kg of silage and it was not significant (P>0.05) among farm locations: It was concluded that preparation of SPBS could be carried out at a reasonable cost in small farmsteads. The technique would also be realistic as outer two bags of each SPBS are kept for re-use. Further studies on farmer adoption on the technique and long term keeping ability of SPBS are also suggested.