收获期对多花黑麦草营养成分和青贮品质的影响

Effects of Harvest Stage on Nutrients and Silage Quality of Different Cultivars of Italian Ryegrass(Lolium multiflorum)

以6个从日本引进的多花黑麦草育成品种为材料,研究了不同品种孕穗期、抽穗期和开花期的营养成分和青贮发酵品质,旨在为多花黑麦草的高效利用提供依据。结果表明:不同生育期多花黑麦草原料的营养成分差异达显著水平(P<0.05)。随着生育期的推进,6个品种的干物质含量均呈现增长趋势,粗蛋白质和干物质体外消化率呈下降趋势,中性洗涤纤维和酸性洗涤纤维含量均呈增加趋势,可溶性碳水化合物含量呈先增加后降低趋势(抽穗期达最高)。青贮发酵品质在不同生育期差异显著(P<0.05),抽穗期青贮pH值为4.11,NH3-N/TN为8.57%,发酵品质显著优于其他两个时期(P<0.05)。对品种的主效应分析表明,品种PI239772的青贮发酵品质最好,其次是品种PI239743和PI239765,PI239764、PI239792和PI239795的青贮品质较差。综合品种和生育期的营养成分和青贮发酵品质,品种PI239743、PI239765和PI239772抽穗期青贮饲草营养品质和发酵品质较好。

The objective of this study was to investigate the feeding and silage quality of 6Italian ryegrass（Lolium multiflorum）varieties cut at booting,earring and blooming stages so as to provide basis for highly efficient utilization of Italian ryegrass.The results showed that the feeding quality had significant differences at different growth stages（P0.05）.As the delay of the growth stage,the feeding quality changes of 6Italian ryegrass varieties were of similar trends.The dry matter（DM）increased continuously,but the crude protein（CP）and the in vitro dry matter digestibility（IVDMD）were continuously decreased as the delay of the growth stage.Along with the growth stage of delay the water-soluble carbohydrate（WSC）first increased and then decreased,and was the highest in earring stage.Silage quality cutting at different growth stages was significant differences（P0.05）.In booting stage,the pH of Italian ryegrass silage was 4.41,the NH3-N/TN content was 21.90%,which demonstrated that it was not an appropriate period to ensile Italian ryegrass;In earing stage,the pH of Italian ryegrass silage was 4.11,the NH3-N/TN content was 8.57%,the silage quality was significantly better than that other two stages.According to the analysis of main effect of varieties,silage quality of Italian ryegrass variety PI239772 was the best,the next was PI239743 and PI239765,and the last was PI239764,PI239792 and PI239795.Based on the feeding and silage quality at different harvest time and varieties of Italian ryegrass,the nutritional quality and the silage quality of Italian ryegrass varieties PI239743,PI239765 and PI239772in earring stage were better.