密度和施氮量对糯玉米鲜穗采收后残余附产物青贮前饲用价值的影响

Effects of Planting Densities and Nitrogen Levels on the Feeding Value of Waxy Corn's Residual by-products after Harvesting of Fresh Ear and before Silaging

随种植密度的提高,鲜穗收获后残余附产物干物质含量先降后增,其产量明显增加,粗脂肪、无氮浸出物、粗纤维含量和产量及可消化总养分产量显著提高,粗蛋白含量和产量以中密度为最高,密度对粗灰分含量无明显影响。随施氮量的增加,鲜穗收获后残余附产物干物质、无氮浸出物、粗蛋白、粗脂肪、粗纤维、粗灰分和可消化总养分产量显著提高,而干物质和无氮浸出物含量先降后增,粗蛋白、粗脂肪含量先升后降,而粗纤维含量逐步下降,粗灰分含量较为稳定。鲜穗收获后残余附产物干物质、粗纤维、粗蛋白、粗脂肪含量分别以高密度施氮100kg/hm2、中密度施氮100kg/hm2、低密度施氮400kg/hm2、高密度施氮300kg/hm2时最高,高密度施氮500kg/hm2时干物质、粗蛋白、粗脂肪、粗纤维、粗灰分、可消化总养分等的产量及无氮浸出物含量和产量最高。

With increasing planting densities,dry matter content of the residual by-products after harvesting of the fresh ear decreases first and then increases considerably.Contents and productions of crude fat,nitrogen free extract,crude fiber and production of total digestible nutrients increase remarkably;content and production of CP are the highest when it＇s medium planting density;densities do not affect the content of crude ash conspicuously.With increasing level of applied nitrogen,productions of dry matter,nitrogen free extract,CP,SF,CF,CA and total digestible nutrients of the residual by-products after harvesting of the fresh ear increase notably;while contents of dry matter and nitrogen free extract increase first and then decrease,contents of CP and CF increase first and then drop,content of crude fiber decreases gradually,and content of CA remains relatively unchanged.Contents of residual by-products＇ dry matter,crude fiber,CP and CF after harvesting of the fresh ear are the highest respectively when nitrogen application of 100kg/hm2 at high density,application of 100kg/hm2 at medium density,application of 400kg/hm2 at low density and application of 300kg/hm2 at high density.When application of 500kg/hm2 at high density,productions of dry matter,CP,CF,CA,crude fiber,total digestible nutrients and content and production of nitrogen free extract reach the highest level.