Estimating the nutritional value of silage made from relay crops and mixtures of grains and protein crops

It is challenging to estimate the nutritional value of immature mixtures of grains and protein-rich plants because INRA's calculations do not account for the diversity of real-life situations (e.g., variability in species composition, conservation method, and growth stage at harvest). A survey of French laboratories that analyse forage samples found that different calculation methods are used, which can lead to major differences in estimations of energy and nitrogen content. In Wallonia, laboratories use near infrared reflectance spectroscopy to analyse forage quality. The results of this study allow us to make several recommendations. For example, clients need to provide precise details about their samples on request forms, including complete descriptions of forage type. In turn, laboratories must carefully choose their calculations based on forage species composition and sample type. Experiments in which these suggestions are implemented are needed to obtain more complete reference information for theses forages.