Potamogeton crispus L. is a kind of nature aquatic plant and widely dispersed over the world with important value in ecology and economy, it was reported that there were many nutritious elements such as proteins,fats, amino acids, fibres, Ca, P, vitamins etc. in it, and the utilizable value of feedstuffs has been understood preliminarily. The appearance that ducks fed with Potamogeton crispus could produce natural red-yolk eggs with good quality and price had been known long ago in Xiantao and Honghu area, Hubei province, the P. R. China, we ha...
