高油298玉米秸秆的适宜收获期及其营养价值与其他品种玉米秸秆的比较优势

以高油玉米品种HOC298、普通玉米品种CAU3138和饲料专用玉米品种FC3为试验材料，研究了高油298玉米秸秆的主要化学成分含量和干物质，纤维组分消化率随籽粒成熟期的变化规律及其与普通玉米秸秆和专用饲料玉米秸秆营养价值的比较。结果表明：随着籽粒成熟度的提高，HOC298秸秆的水溶性精、淀粉、粗脂肪含量以及干物质消化率吊线性规律（L；P〈0．01）提高，而NDF、ADF和木质素含量则呈线性规律（L；P〈0．01）降低。因此，HOC298玉米秸秆的适宜收获期推荐为4／4乳线期。在4／4乳线期，HOC298秸秆的水溶性糖、淀粉和粗脂肪含量不仅极显著高于（P〈0．01）CAU3138秸秆，也显著高于（P＜0．06或P〈0．01）3／4乳线期的FC3秸秆，而NDF、ADF和木质素含量则正相反（P〈0．001）。HOC298秸秆的干物质、NDF消化率以及动态产气量均极显著（P〈0．01）高于CAU3138秸秆和3／4乳线期的FC3秸秆。可见，籽粒成熟后的HOC298玉米秸秆不仅营养物质岔量较高，而且消化率也较高，是反刍动物较理想的粗饲料。

Optimum Harvest Time of High Oil Corn 298 Stalks and Their Superiority in Nutritional Value Comparing with Other Corn Variety Stalks

Three types of stalks from high oil corn variety(HOC 298),conventional corn(CAU3138) and specific fodder corn(FC3) were used to determine the alteration of main chemical contents and in vitro digestibility of HOC 298 stalks with kernel maturity stage and the difference of HOC stalks to other variety of corn stalks.The result showed that as the corn kernels matured,HOC298 stalks had linear increases(L;P<0.01) in the contents of water soluble carbohydrate(WSC),starch and ether extract(EE),and the digestibility of DM(DMD),but had a linear decrease(L;P<0.01) in the contents of NDF,ADF and lignin.The optimum harvest time for high oil corn HOC298 was,therefore,recommended at 4/4 milk line of kernels.The content of WSC,starch and EE of HOC298 stalks was not only much higher(P<0.01) than that of CAU3138 stalks harvested at 4/4 milk line,but also higher(P<0.06 or P<0.01) than that of FC3 stalks harvested at 3/4 milk line,whereas the content of cell walls including NDF,ADF and lignin of HOC 298 stalks was significantly lower(P<0.001) than that of CAU3138 and FC3,respectively.The stalks of HOC298 had higher(P<0.01) in vitro DMD and NDFD,and ruminal gas production than those of CAU3138 and FC3 stalks.These results suggested that HOC298 stalks harvested at 4/4 milk line stage of kernels are characterized by their high nutrient contents and being more ruminally digestible,and seem to be of highly valuable over other corn stalks.