我国不同自然区域天然牧地和人工牧地营养价值的比较研究

从天然牧地看 ,青藏大区具有高蛋白、高脂肪、高无氮浸出物、高灰分、高代谢能及低纤维 (即 5高 1低 )的特征 ;南方大区恰好相反 ,呈现为 5低 1高的特征 ;北方大区的各项营养成分含量居中。就人工牧地而言 ,粗蛋白含量亦为青藏大区较高 ,粗脂肪和粗灰分则以南方大区较高 ,而粗纤维、无氮浸出物和代谢能 3个大区相近。人工牧地与天然牧地比较 ,前者的粗蛋白、可消化蛋白、Ca和P的含量显著地高 ,营养比和粗脂肪明显地低 ,而 2类牧地的代谢能、粗纤维、无氮浸出物和粗灰分相近或略有差异。由此表明 ,人工牧地在营养价值方面优于天然牧地 ,原因主要在于其蛋白质含量较高、营养比较低。

A Comparative Study of Nutritive Value between Natural Rangeland and Artificial Rangeland in Different Regions of China

As regards natural rangeland,the nutritive value of Qinghai-Tibet large region possessed the characteristic of high protein,high fat,high nitrogen-free extract,high ash,high metabolic energy and low fiber,5 high contents and 1 low content;and of the south large region were just opposite from the aforesaid character,5 low contents and 1 high content were showed.The contents of each nutritive composition in the north large region mediated between aforesaid 2 large region.As far as artificial rangeland was concerned,the contents of crude protein of Qinghai-Tibet large region were also high,while the contents of crude fat and crude ash of the south large region were higher;but of crude fiber,nitrogen-free extract and metabolic energy were similar for 3 large region.Compared artificial rangeland with natural rangeland,the contents of crude protein, digestible crude protein,Ca and P were a markedly high, nutritive ratio and crude fat were obviously low for the former;but metabolic energy,crude fiber,nitrogen-free extract,crude ash of 2 type rangelands were a close or made a little difference.These showed that, the superiority of artificial rangeland to natural rangeland in nutritive value was largely that the protein was high and nutritive ratio was small for the former.