Sea weeds

Besides lakes, rivers and ponds, India has two thousands kilometers long coastline and wide variety of aquatic plants are abundantly available which are regarded more as a problem rather than as a resource. According to the FAO estimate, India produces about 5.5 thousand tonnes of sea weeds and other aquatic plants on wet basis annually. Recently, aquatic plants have been recognized as potentially valuable resources for animal feeding. However, problems exist in harvesting and processing as they grow in water and contain high moisture content (85-95%). Algae, seaweeds and water hyacinth are the important aquatic plants, which have potential for animal feeding.

The seaweeds are suitable for feeding to ruminants and most classes of swine as these are rich in essential minerals. As regards the animal performance in terms of milk and fat yield, feeding of seaweeds up to 30 % in the concentrate mixtures did not have any adverse affect. Their incorporation into calf starter at 20 % level resulted in lower growth, but the difference was non-significant in comparison to the control group. The CP digestibility did not differ but the availability of TDN to calves was lowered. Incorporation of dried sea weed (S. wightii) in the total ration at 10 % level increased milk yield and milk production efficiency in Sahiwal cows and it can be used as a source of minerals.

Feeding of freshwater hyacinth is not suitable for animals as the cattle often suffer from diuresis and diarrhea. Therefore, hay or silage making are most suitable methods for its effective utilization. Since hay making is difficult due to inclement weather and its availability in rainy season. Silage making with dry crop residues is an ideal way to utilize water hyacinth for ruminants. Addition of 1 to 2 % urea during the silage making was found to be very effective. The nitrate, oxalate and tannin contents of hydrilla and water hyacinth did not appear to be a health hazard in cattle diets. Information regarding the presence of pathogens in water hyacinth is not available.