ABSTRACT

The effect of defoliation frequency and severity on FA and nutrient composition of forage chicory (Cichorium intybus L.) before and after vernalisation were compared. Before vernalisation, the FA and nutrient components exhibited little variation with defoliation frequency and severity irrespective of the time of day. After vernalisation, total FA more than halved compared with pre vernalisation levels (52.2 versus 19.2 mg/g DM). Concentrations of total FA and polyunsaturated FA: linoleic and linolenic declined by 63%, 50%, and 74%, respectively. Furthermore, extending the defoliation frequency from 300 to 600 growing degree-days after vernalisation caused a decline of 28% of linoleic, 40% of linolenic and 33% of total FA concentrations. Diurnal fluctuations were detected for linoleic and oleic acids after vernalisation (P < 0.01). In terms of nutrient composition, vernalisation decreased CP, digestibility and ME, while fibre contents increased. Between morning and afternoon, there were general declines in CP and fibre contents as well as increases in soluble sugars the herbage regardless of vernalisation. Overall, the feeding value and the concentration of FA were greater on chicory herbage managed under shorter regrowth intervals than that under longer regrowth intervals, which is likely to favour animal production and the concentration of the desirable FA in ruminant products.

摘要

落叶频率和严重程度对菊苣（菊苣）的FA和营养成分的影响。L.）进行了春化前后的比较。春化前，FA和营养成分随叶的脱落频率和严重程度变化不大，与一天中的时间无关。春化后，总脂肪酸与春化前的水平相比减少了一半以上（52.2对19.2 mg / g DM）。总脂肪酸和多不饱和脂肪酸的浓度：亚油酸和亚麻酸分别下降了63％，50％和74％。此外，将春化后的脱叶频率从300个生长日扩展到600个生长日，导致亚油酸含量下降28％，亚麻酸含量下降40％和总FA浓度下降33％。春化后检测到亚油酸和油酸的日变化（P <0.01）。就营养成分而言，春化降低了CP，消化率和ME，而纤维含量却增加了。在早晨和下午之间，无论春化处理如何，牧草的CP和纤维含量普遍下降，而可溶性糖含量却有所增加。总体而言，在较短的再生间隔下管理的菊苣草的饲喂价值和FA浓度要大于在较长的再生间隔下管理的菊苣草，这可能有利于动物生产和反刍动物产品中所需FA的浓度。