- Article
Comparative Assessment of On-Site and Commercial Laboratory near Infrared Reflectance Spectrometer Measurements of Fresh Maize
- Kevin J. Shinners,
- Peter Schade and
- Matthew F. Digman
- + 1 author
Whole-plant maize (corn) (WPC) is a critical forage in ruminant diets, and rapid, reliable measurement of its nutritional composition is essential for precision feeding. We hypothesized that an on-site near-infrared spectroscopy (OS-NIRS—specifically, HarvestLab™ 3000) sensor would provide within-laboratory repeatability comparable to commercial analytical laboratories (ALs) and inter-laboratory reproducibility similar to conventional laboratory analyses. To test this, WPC samples were collected across three experiments and two countries (USA and Germany) and analyzed by both OS-NIRS and ALs, with precision metrics calculated according to ISO 5725. Results showed that OS-NIRS achieved intra-laboratory repeatability equal to or greater than ALs, particularly for protein and starch. The repeatability performance of the OS-NIRS sensors was similar to that of ALs for moisture and NDF. Inter-laboratory reproducibility varied widely across constituents and experiments. Including OS-NIRS data with AL measurements produced inconsistent effects—sometimes narrowing confidence intervals but more often widening them—while OS-NIRS data alone demonstrated repeatability on par with ALs but mixed reproducibility outcomes. Inclusion of OS-NIRS data did not introduce systematic bias and, in some cases, improved consistency. These findings indicate that OS-NIRS can complement laboratory analyses by providing timely, farm-level measurements that enhance decision-making in feed management.
7 February 2026




![Location of field experiment site in Pukekohe (−37.3187 S, 174.9985 E). Adapted from Ref. [22].](https://mdpi-res.com/cdn-cgi/image/w=281,h=192/https://mdpi-res.com/agriengineering/agriengineering-08-00054/article_deploy/html/images/agriengineering-08-00054-g001-550.jpg)


