Xu Xuan, Min Doohong
Department of Agronomy, Kansas State University, Manhattan, KS 66506, USA.
J Anim Sci Technol. 2022 Mar;64(2):262-273. doi: 10.5187/jast.2022.e10. Epub 2022 Mar 31.
Under the four-cut system, low-lignin alfalfa ( L.) may extend harvesting intervals improving harvest management flexibility and producing forage products with higher nutritive values. The objective of this study was to compare forage yield and nutritive values of low-lignin and conventional alfalfa varieties when applied to six different harvest schedules in the first (2016) and second (2017) production years. There were 12 treatments of two alfalfa varieties as whole plots and six harvest schedules as subplots. Across harvest schedules, there were four cuttings in two production years. Three harvest intervals including "Standard" (high quality, HQ), "Standard+5-day" (medium quality, MQ), and "Standard+10-day" (high yield, HY) were chosen for the first cutting, and 30-day (HQ) and 35-day (HY) for the second cuttings. The third and fourth cuttings in 2016 were timed near final harvest date and in 2017 occurred at 35-day (MQ) and 40-day (HY). Variety by harvest schedule interaction was not significant, but the whole plot and sub-plot effects were significant. Hi-Gest 360 was consistently higher in nutritive value and with a similar yield as Gunner. Harvest schedules did not consistently differ in forage yield and nutritive values. HS-1 ("Standard" + 35-day + Medium Quality + High Yield) with shorter first two cutting intervals provided lower acid detergent fiber (ADF), neutral detergent fiber (NDF), higher relative feed value (RFV), and similar forage yield compared to other schedules. HS-1 had the highest economic incomes when considering RFV and yield among the six different harvest schedules.
在四刈割系统下，低木质素苜蓿可能会延长收获间隔，提高收获管理的灵活性，并生产出营养价值更高的饲料产品。本研究的目的是比较低木质素苜蓿品种和传统苜蓿品种在2016年第一季和2017年第二季生产年份应用于六种不同收获计划时的牧草产量和营养价值。有两个苜蓿品种作为主区，六个收获计划作为副区，共12个处理。在两个生产年份中，各收获计划均进行四次刈割。第一次刈割选择了三个收获间隔，包括“标准”（高品质，HQ）、“标准+5天”（中等品质，MQ）和“标准+10天”（高产量，HY），第二次刈割选择了30天（HQ）和35天（HY）。2016年的第三次和第四次刈割时间接近最终收获日期，2017年的第三次和第四次刈割分别在35天（MQ）和40天（HY）进行。品种与收获计划的交互作用不显著，但主区和副区效应显著。Hi-Gest 360的营养价值始终较高，产量与Gunner相似。收获计划在牧草产量和营养价值上并非始终存在差异。与其他计划相比，前两次刈割间隔较短的HS-1（“标准”+35天+中等品质+高产量）提供了较低的酸性洗涤纤维（ADF）、中性洗涤纤维（NDF），较高的相对饲用价值（RFV），且牧草产量相似。在六种不同的收获计划中，考虑到RFV和产量，HS-1的经济收益最高。
