Abstract:

[Objective]To determine the optimal harvesting time of the Baiyangdian crispus (Potamogeton crispus L.), [Methods]During course of April and June in 2009, feed analyses were employed after the fresh crispus samples were harvested at three fixed regions of Baiyangdian lake in Hebei province once a week, and dried.[Results]The crude protein and ether extract contentsof crispus powders, harvested between April 21 and May 12, were significantly higher than those collected later (P<0.05). Crude ash and calcium contents of crispus samples, harvested between May 19 and June 1, were significantly less than those harvest previously (P<0.05). The coefficients of variations of nutritive contents were ranked calcium > phosphorus > crude protein > ether extract > crude ash > crude fibre > nitrogen free extract.[Conclusion]In general, Baiyangdian crispus are of high nutritive. It should be harvested in the mid-April to mid-May, its feeding value need to be testified with further animal trials later on.