摘要： 谷子在我国农牧结合区和牧区正在发展成为专用饲草作物，但对谷子饲草的生长发育和营养变化动态缺乏研究，对最佳刈割期不了解，影响了谷子饲草生产和产业发展。本研究以饲草谷子1号为材料，研究了饲草谷子株高、粗蛋白、粗脂肪、粗纤维、中性洗涤纤维和酸性洗涤纤维等生长和变化动态，结果表明:从拔节至开花后一周的灌浆初期，是饲草谷子鲜质量和干质量的主要形成期，并在灌浆初期鲜质量和干质量达到最高，分别为33.0 t/hm²和12.80 t/hm²。饲草谷子粗蛋白含量在幼苗期含量最高为干草质量的22%，随发育进程的推进而逐渐减低，到乳熟期干饲草粗蛋白含量降为7.3%；饲草谷子粗脂肪的含量随生育期的进程表现了前期含量低，中期含量高，后期含量再降低的动态趋势。单位面积谷子饲草的粗蛋白和粗脂肪产量均在开花后1周的灌浆初期达到最高，以后开始迅速降低。粗纤维、中性洗涤纤维和酸性洗涤纤维也在开花后的灌浆初期达到最大产量。综合本研究的结果，开花后7 d左右是饲草谷子的最佳刈割期，结合生产中的实际情况，从开始开花至群体开花结束的灌浆初期是饲草谷子的适宜刈割期。

关键词: 谷子, 饲草, 营养动态, 收割期

Abstract: Foxtail millet ( Setaria italica Beauv． ) is on its way developing as a new type of forage crops for hayproduction in northern China including Inner Mongolia and other cold high land regions． But the lack of knowledgeabout its growth and nutritive changing dynamics and optimum harvest stage hinds its development for hay production． Using Sicaoguzi 1 as sample， this paper reports our study on growth dynamics and nutritive component dynamics of foxtail millet forage， including crude protein， crude fat， crude fiber， neutral detergent fiber and acid detergentfiber． Results indicated that fresh and dry matter accumulation mainly occurred during a period from the beginningof stem elongation stage to the starting stage of seed filling． The crude protein content was as high as 22% at theshooting stage 50 days after sowing， and it declined combining with the progress of plant development and a 7． 3 %of crude protein content was detected at the seed middle filling stage． Crude fat content of foxtail millet hay was about 1 ． 6% to 2． 2% before heading stage and it reaches 3 ． 3 % at the heading stage and then declined to 2． 7% atthe seed middle filling stage． Both crude protein and crude fat reaches its highest yield at the starting stage of seedfilling 92 days after sowing， which is about 7 days after flowering． The yielding of crude fiber， neutral detergent fiberand acid detergent fiber were also reaching their highest point at the starting stage of seed filling． So it is reasonableto suggest that the starting stage of seed filling， which is about 7 days after flowering begins， is the optimum harvesting stage for foxtail millet hay production．

Key words: Foxtail millet, Forage, Nutritive dynamics, Harvesting time

中图分类号: 

• S54