A note on estimation of quality parameters in perennial ryegrass by near infrared reflectance spectroscopy

The objective of this study was to assess near infrared reflectance spectroscopy (NIRS) as a rapid method for estimating quality parameters in perennial ryegrass (Lolium perenne L.) and to evaluate its suitability for use in selection for improved quality in this species. NIRS calibrations were derived for digestible organic matter in dry matter (DOMD), water-soluble carbohydrate (WSC) and crude protein (CP). To maximise variability, a set of samples for analysis were selected from field and glasshouse, and harvested at different maturity stages over 2 years. The samples were analysed by standard laboratory methods for DOMD, WSC and CP. The calibrations obtained from the study had a high level of accuracy (r 2 values 0.92, 0.96, 0.96; standard errors of prediction 16.1, 11.9 and 6.8 g/kg dry matter for DOMD, WSC and CP, respectively) and the results confirm that NIRS is a rapid and cost effective method which can be applied in selection for improved ryegrass quality.