Source: Hindu,
September 20, 2007
Fodder is an important requirement for cattle. Even if the animals are fed with commercial feeds from the market, fresh green grass or dry straw is a must for them as fodder availability greatly reduces the expenditure on commercial feeds.
The success of a dairy plant depends largely on increasing milk production without escalation in feeding cost. Growing fodder grass is a good option. Another is azolla cultivation.
Azolla is a floating fern which resembles algae. It is rich in proteins, amino acids, vitamins and minerals. Experiments conducted by the Vivekananda Kendra-Natural Resources Development Project (VK- NARDEP), Kanyakumari district, Tamil Nadu have proved that the quantity and quality of milk yield of cattle went up when they were fed with azolla.
With support from the Department of Biotechnology (DBT), the research team at the institute has developed a sustainable model for backyard azolla cultivation.
Mass multiplication
“Normally azolla is grown in paddy fields or shallow water bodies. In some places it is grown in concrete tanks. Studies conducted at our institute found that both these methods are not very conducive for its mass multiplication to be used as biofeed for cattle.
“Our research team has developed the silpauline lined pit method or NARDEP method which is popular among farmers,” said Mr. G. Vasudeo, Secretary of the institute.
The soil is first cleared of weeds and levelled. Bricks with a length of about 10 cm are lined horizontally in a rectangular fashion.
A UV stabilised silpauline sheet of 2.5 x 1.8 mt size with 150 gm thickness is uniformly spread over the bricks in such a way as to cover the margin of the rectangle made by the bricks.
About 30-35 kg of sieved soil is uniformly spread over the silpauline pit, which will provide the primary nutrient base for Azolla.
Carbon source
About 4-5 kg of two day old cow dung is made into a slurry (fresh biogas slurry may also be used) after mixing it in 15-20 lts of water, which provides the carbon source for Azolla.
About 40 gms of macro-nutrient mix (mixing 10kg of rock phosphate, 1.5 kg of magnesium and 20-50 gm of muriate of potash) are mixed in the slurry before pouring it into the azolla bed. (Another macro nutrient mix named Azofert can also be used).
Level of water
Water level is maintained at about 7-10 cm in the pit. Wastewater from bathroom and cattle shed can also be used to fill the pit.
Where there is a problem of fresh water availability, the water left after washing clothes (after the second rinsing) can also be used.
About 1-1.5kg of pure mother azolla culture seed material is spread uniformly over the water, after mild stirring of soil and water in the azolla bed. Fresh water should be sprinkled over the azolla immediately after inoculation to make the azolla plants upright.
In a week’s time, the azolla spreads all over the bed and develops a thick mat like appearance. Harvesting can be done every day from the 7th day onwards with the help of a plastic sieve or tray with holes at the bottom.
Cowdung and minerals removed by the azolla biomass have to be supplemented at least once in seven days. The harvested azolla should be washed in fresh water to get rid of the cow dung smell.
Mixing ratio
Fresh azolla thus collected can be mixed with commercial feed in the ratio 1:1 or given directly to livestock. It was found that the milk production in cattle increased by 10-12 per cent when they were fed with azolla and there was 20-25 per cent savings on buying commercial feeds, according to Dr. Kamalasanan Pillai, Scientist at the Institute.
Increase in body weight
Azolla can also be fed to poultry birds. It was observed that the birds grew faster and there was 10-12 per cent increase in their total body weight compared to the birds which were given only normal diet.
The egg yolk increased and the egg shell colour became glossy in appearance. In addition the azolla bed acts as a rain harvesting station and live mulch for the fields.
About 2kg of soil in the azolla bed is almost equal to about 1 kg of commercial NPK fertilizer after six months.
For more information readers can contact Mr. G. Vasudeo, Secretary, VK- NARDEP, Vivekanandapuram, Kanyakumari, Tamil Nadu 629-702, email:
ngc_vknardep@sancharnet.in, phone: 04652-246296, mobile: 9442646296 and Dr. Kamalasanan Pillai, Scientist, mobile: 093872-12005.