A.B. Idris, S.M. Yusoff and A. Sharif
Department of Veterinary Services
In Malaysia, livestock production is mainly in the hands of smallholders, who are largely dependent on forages for their feed resources. With the assistance of the Department of Veterinary Services (DVS), more farmers are now cultivating forages, especially those involved in the milk collecting centre (MCC) dairy projects. Owing to events such as droughts and floods, fodder conservation is likely to play an important role in livestock production among smallholders in certain areas of the country.
Sweet corn is a popular crop in Malaysia. After its cobs have been harvested, the stover still remains a good source of nutrients, suitable for cattle feeding. With 9.6% CP concentration, as found in an earlier study, it is comparable to that of stover harvested at 75 days of age (Yacob et al., 1992). The ME value - 7.82 MJ/kg of fresh stover - is comparable to or in some cases better than most fodder grass species being used in Malaysia. Although this by-product is a valuable forage by itself in the fresh state, at harvesting time the quantity would be too much to be utilized in the short time before it started to decompose. This material needs to be conserved for feeding in adverse seasons. Ensiling the stover is thought to be the best form of conservation. At present, the production of sweet corn silage is carried out in the state of Terengganu, with an estimated production of 120 t annually. Since the inception of the sweet corn stover ensilage programme in 1996, an estimated 400 t have been produced for feeding farmers' cattle.
MATERIALS AND METHODS
The stover of sweet corn harvested after 75 days was collected and chopped into 2 cm lengths, using a portable forage chopper. The chopped stover was tightly packed into 128-litre plastic drums, taking care to exclude as much air as possible so to maintain anaerobic conditions for successful ensilation.
The ensiled material was opened after 30 days and samples were sent to the laboratory for analyses using AOAC (1984) methods. Calcium concentration was determined using an atomic absorption spectrophotometer; phosphorus using the molybdate metavanadate complex; ME by the gas test procedure, as outlined by Menke et al. (1975); and the fibre components using the method of Goering and Van Soest (1970).
RESULT AND DISCUSSION
Yacob et al. (1992) estimated production of 10 t of DM of stover per ha of sweet corn - a figure close to the average of 12 t achieved here. Clearly, a substantial quantity of forage could be obtained if stover from all sweet corn crops were ensiled and used by dairy smallholders.
At the normal harvesting age of 75 days, the protein and ME contents of corn stover were 9.6% and 7.82 MJ/kg respectively. In the silage product, the protein concentration had decreased to 8.2% and ME value to 5.86 MJ/kg. Very negligible spoilage was observed in the drums during the project.
AOAC. 1984. Official Methods of Analysis (14th edition). Association of Official Analytical Chemists, Arlington, Va., USA.
Goering, H.K., & Van Soest, P.J. 1970. Forage Fibre Analyses (Apparatus, reagent, procedures and some applications). USDA Agricultural Handbook, No.379.
Menke, K.H., Raab, L., Salewski, A., Steinggas, H., Fritz, D., & Schneider, W. 1975. The estimation of the digestibility and metabolizable energy content or ruminant feeding stuffs from the gas production when they are incubated with rumen liquor in vitro. J. Agric. Sc.(Cambridge), 93: 217-222.
Yacob, M.A., Alimon, A.R., & Hilmi, A. 1992. Nutritive evaluation of sweet-corn stover silage for growing lambs. p. 203-206, in: H.K. Wong et al. (eds) Towards more efficient, effective and minimal production strategies. Proceedings 15th Malaysian Society of Animal Production Conference.