Comparison of near infrared calibrations for estimating in vitro digestibility in whole-plant corn hybrids

• Published in: Canadian journal of animal science Vol. 67; no. 2; pp. 557 - 562
• Main Authors: Valdes, E.V, Hunter, R.B, Jones, G.E
• Format: Journal Article
• Language: English
• Published: 01-06-1987
• Subjects: calibration; corn; digestibility; estimation; infrared spectroscopy
• ISSN: 0008-3984; 1918-1825
• DOI: 10.4141/cjas87-055

A comparison of two near infrared (NIRA) calibrations (C
1
and C
2
) for the prediction of in vitro dry matter digestibility (IVDM) in whole-plant corn (WPC) was conducted. C
1
consisted of 40 WPC samples collected from four locations across Ontario (Brucefield, London, Guelph and Elora). C
2
consisted of 90 samples and included the above locations plus Pakenham and Winchester. Nine wavelengths were used in both equations but only three were common in C
1
and C
2
equations. These wavelengths were 2139 nm, 2100 nm, and 1445 nm, respectively. The predictions of IVDM utilizing both C
1
and C
2
were good. Coefficients of determination (r
2
) and standard error of the estimate (SEE) for calibration and prediction sets were 0.91, 1.7; 0.85, 1.7 for C
1
and 0.88, 1.6; 0.77, 1.6 for C
2
respectively. Regression analysis within location, however, showed low r
2
values for the prediction of IVDM for Pakenham and Winchester in both calibrations. The more mature stage of harvest at these locations might be the cause of the poorer predictions. Key words: In vitro digestibility, whole-plant corn, near infrared reflectance