Study On Feeding Value Evaluation And Difference Of Silage Maize Varieties In Different Harvest Periods

Variety is an important factor affecting the yield and quality of silage maize.The nutrient composition of silage maize plants changes constantly with the growth period.The suitable harvest period plays a decisive role in the yield and quality of silage maize.Therefore,it has important guiding significance for silage corn production to select suitable maize varieties for local planting,determine the best harvest period,and study the nutrient composition and yield variation law of silage maize in different harvest periods.In this study,26 corn varieties were used as experimental materials to study the effects of different harvest periods on the nutritional composition,feeding value and yield of silage corn,identify the suitable varieties of silage corn and determine the best harvest period,in order to provide a theoretical basis for the production and promotion of silage corn in Tumechuan Plain.The main research results are as follows:(1)The dry matter content,hay yield and starch content of silage corn increased with the growth process.Crude protein content decreased continuously;The contents of neutral detergent fiber and acid detergent fiber decreased first and then increased.Soluble sugar,fresh grass yield,relative feeding value and forage grading index increased first and then decreased.Based on the nutritional quality,feeding value and biological yield of silage maize,the best harvest period of whole silage maize in Tumechuan Plain area is early wax ripening.(2)The yield of fresh grass was 69.60～121.11 t/hm~2,and the yield of hay was24.99～37.46 t/hm~2,jingke silage 205,G1839,Xianyu 508 and S1602 had higher yields,which could be used as high yield silage corn varieties to be widely planted.(3)Dry matter content of silage maize varieties tested 27.41%～40.85%;Crude protein content 6.33%～7.58%;Soluble sugar content 19.25%～24.57%;Neutral detergent fiber content 44.40%～53.92%;Acid detergent fiber content 23.19%～28.34%;Starch content29.34%～36.99%;Relative feeding value 118.26%～146.58%;Forage grading index was10.82～18.94MJ.After comprehensive comparison,Dika 159,Dika 186,S1602 and Z658had higher nutritional composition and feeding value,and could be used as high-quality silage maize varieties to be popularized and planted.(4)According to the comprehensive evaluation of silage maize varieties by grey relational analysis,the best silage maize variety is S1602,and the top 5 varieties are S1602,Dika 159,Dika 186,Z658 and Jingke silage 205,which are suitable for popularization and planting in Tumechuan plain.(5)Correlation analysis showed that the biological yield of silage maize was positively correlated with plant height,ear height and stem diameter.The number of green leaves was positively correlated with the yield of fresh grass.Crude protein was negatively correlated with neutral detergent fiber and positively correlated with forage grading index.The yield and quality of silage maize can be improved by cultivation measures and nutrition regulation.