Azolla as an organic quality livestock feed in improving milk production
ABSTRACT
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. High protein and low lignin content contribute for its high digestibility by livestock. Azolla can be mixed with commercial feeds in 1:1 ratio for feeding livestock (Pillai et al., 2005). Azolla as a low cost organic quality feed ingredient, it improves both quality and quantity of milk yield in bovines. Hence, dairy farmers can gain profit in their occupation. Besides dairy animals, it may be supplemented in feed for sheep, goat, pig, rabbits and poultry.
INTRODUCTION
Green plants have long been recognized as the cheapest and most abundant potential source of proteins because of their ability to synthesize amino acids from a wide range of virtually unlimited and readily available primary materials (Fasuyi and Aletor, 2005). The demand for milk and milk products in India is creating new potential in the profitability of dairy farming as an occupation. At the same time, there is a substantial decline in fodder availability. (Pillai et al., 2005). The area under forest and grasslands is decreasing, largely due to the introduction of high yielding dwarf varieties of cereals. In addition the area under food crops is also declining owing to urbanization and industrialization. The shortage of fodder due to ever decreasing area under cereals and fodder crops is getting compensated with increased use of commercial cattle feed, resulting in increased costs of milk production (Reddy, 2007). Several attempts have been made to find alternate sources of cattle feed. Azolla is considered as the most economic and efficient feed substitute and a sustainable feed for livestock.
IMPORTANCE OF AZOLLA
Azolla is an aquatic fern consisting of a short, branched, floating stem, bearing roots which hang down in the water. The leaves are alternately arranged, each consisting of thick aerial dorsal lobe containing green chlorophyll and a ventral lobe which is slightly larger thin, colourless, floating. Under some conditions, an anthocyanin pigment gives the fern a reddish-brown colour. They give the appearance of a dark green to reddish carpet, except Azolla nilotica that does not produce the red anthocyanin pigment. The most remarkable characteristic of Azolla is its symbiotic relationship with the nitrogen-fixing blue-green alga (Cyanobacterium) Anabaena Azollae. The fern provides nutrients and a protective cavity in each leaf to Anabaena colonies in exchange for fixed atmospheric nitrogen and possibly other growth-promoting substances (Lumpkin et al., 1980). Research and promotion of Azolla as a livestock feed has been increasing. Because Azolla has a higher protein content (19-30%) than most green forage crops and aquatic macrophytes, and an essential amino acid composition (notably lysine) favourable for animal nutrition, Azolla can be a valuable protein supplement for many species, including ruminants, poultry, pigs and fish (Hasan et al., 2009).
Nutrient Content of Azolla
The nutritive value of Azolla is well documented which shows that it is a good source of protein with almost all essential amino acids required for animal nutrition. It also provides minerals like calcium, magnesium, potassium, and vitamins like vitamins A and B12. It is reported that on a dry weight basis, it contains 25 – 35 percent protein, 10 – 15 percent minerals and 7 – 10 percent of amino acids, bio-active substances, and bio-polymers. Azolla is also rich in iron (1000–8600 ppm dry weight), copper (3–210 ppm dry weight) manganese (120–2700 ppm dry weight), vitamin A (300–600 ppm dry weight.), vitamin A (300–600 ppm dry weigh), chlorophyll and carotenes. It contains 4.8–6.7% dry weight crude fat. The carbohydrate and fat content of Azolla is very low.
AZOLLA CULTIVATION
Azolla growth is promoted by some optimal ecological factors. It grows in water or wet mud, and it dies within a few hours under dry conditions. Azolla can survive a water pH range of 3.5–10, but optimum growth occurs when pH is between 4.5-6.5 and salinity of between 90-150 mg/L. The optimum temperature for Azolla is between 64 – 82°F (18– 28°C). Azolla grows in full to partial shade (100–50% sunlight), with growth decreasing quickly under heavy shade. Azolla is established by vegetative propagation (Kathirvelan et al., 2015). Preparation : An artificial water body preferably under the shade is made to grow Azolla. 1. A pit size of 2 Mt. length, 1 Mt. width and 20cm depth should be dug on earth. 2. This pit is then covered with plastic gunnies to prevent the growth of roots of nearby trees, protect the soil temperature and seepage water. 3. Silpuline plastic sheet / plastic sheet is spread over the plastic gunnies without any fold. 4. About 10-15 kg sieved soil is uniformly spread over the plastic sheet. 5. Five kg of cow dung and 40 gms of Azophos and 20 gms of Azofert or single super phosphate made into slurry in 10 liters of water and is pour in the pit, then more water is poured to make the water level at about 8 cm. 6. About 1-2 kg of fresh, pest and disease free Azolla seed culture is inoculated in the pit. 7. Azolla will fill the pit within 7-10 days. About 1-1.5 kg of Azolla can be harvested daily thereafter. 8. About 2kgs of dung, 25gms of Azophos and about 20gm of Azofert made into a slurry in 2 liters of water should be applied once in 7 days to keep the Azolla in rapid multiplication phase and to maintain the daily yield of 1- 2kg/pit.
Harvesting and preparing Azolla as livestock feed (NARDEP)
- Harvest the floating Azolla plants using a plastic tray having holes of 1 to 2cm mesh size to drain the water. 2. Wash the Azolla to get rid of the cow dung smell. Washing also helps in separating the small plants which drain out of the tray. The plants along with water in the bucket can be poured back into the original bed. 3. For use as a livestock feed, the fresh Azolla should be mixed with commercial feed in 1:1 ratio to feed livestock. After a fortnight of feeding on Azolla mixed with concentrate, livestock may be fed with Azolla without added concentrate. 4. For poultry, Azolla can be fed to egg layers as well as broilers. 5. In case of severe pest attack the best option is to empty the entire bed and lay out a fresh bed in a different location.
Precaution:
- Plants should not be allowed to enter maturity stage or sporulation stage by periodic application of cow dung slurry, super phosphate and other macro and micronutrients except nitrogen. Temperature should be retained below 30 degree centigrade, in case the temperature goes up, the light intensity should be maintained by providing shade net or other devices. 2. Bio-mass should be removed every day or alternative days to avoid overcrowding. 3. pH should be tested periodically to see that it never goes below 5.5 and above 7. 4. Seed stock is maintained separately, treated with pesticides and fungicides. 5. Biomass collected from the field applied with the pesticide should not be used as a feed for livestock.
BENEFITS OF AZOLLA
Balanced and proper feeding results in better utilization of nutrients and optimum milk production. There will be a substantial improvement in the quantity, as well as, quality of milk produced, when dairy cattle are fed with Azolla combined with commercial feed along with an improvement in the health of the cattle. The cost of producing Azolla using NARDEPS’ method is less than Rs 0.65 per kilogram. The expenditure on preparing a 6 X 4 feet pond is minimal at Rs.500 (sheet plus labour cost). A farmer can realize a net profit of over Rs. 4000 per annum from the additional milk yield and reduced usage of concentrates’ feeding for livestock. Nidhi et al., 2015 stated 11.85% increase in milk yield after Azolla supplementation in dairy cows. They observed that the milk productivity started to increase after one week of Azolla supplementation, which further increased for next four weeks and thereafter it became constant at increased level. A study by Giridhar et al., 2012 on Azolla cultivation and feeding to milch animals @ 800 grams (fresh weight) on an average per day, improved the monthly milk yield by at least 10 liters per cow. The net profit per annum was over Rs. 4000 when additional milk yield due to feeding of Azolla and savings in usage of concentrates for milch animal were considered. Meena et al., 2017 also reported about 16.25 % increase in the milk yield in lactating buffaloes after 60 days of feeding 1.5 Kg Azolla per day with conventional feed cottonseed cake. The same was reported by Singh et al., 2017 and Mathur et al., 2013.
CONCLUSION
Azolla fodder is an excellent alternate feed supplement for livestock, poultry and fish. It is a good source of protein and contains almost all essential amino acids and minerals such as iron, calcium, magnesium, potassium, phosphorus, manganese etc. apart from appreciable quantities of β-carotene (vitamin A precursor) and vitamin B12. It is considered to be the most promising because of the ease of cultivation, high productivity and good nutritive value. It is a highly productive plant and it doubles its biomass in 4–10 days period. This is a boon for dairy farmers because; it drastically reduces the feed cost and results in increased milk yield.
Azolla – Friend of the Farmers
Azolla – Friend of the Farmers
