Dry Matter Disappearance by Enzyme and Aqueous Solutions to Predict the Nutritive Value of Forages

Open Access
Publisher Website
Google Scholar
Abstract
Studies are reported on the development of a simple and rapid laboratory technique for predicting the digestible energy potential of a forage as expressed by its Nutritive Value Index (NVT). A 1-g forage sample was placed in a 200ml screw-cap centrifuge bottle to which was added 75ml of test solution, with or without enzyme addition. The samples were agitated 24 hr in an A.O.A.C. pepsin digester placed in an incubator held at 40 C. Following agitation, the bottles were centrifuged at 1900rpm for 10 min and the residue transferred to preweighed Selas filtering crucibles for dry matter determinations, with dry matter disappearance (DMD) calculations based on the original dry matter content of the forage substrates. The following highly significant (P<.01) correlations were found between the Nutritive Value Indices of 14 forages as determined in vivo with sheep and per cent DMD with (A) distilled water, 0.90; (B) KH phthalate buffer solution (pH 4), 0.91; (C) phthalate buffer + cellulase, 0.92; (D) phthalate buffer + cellulase and pepsin, 0.93; (E) 0.075 N HC1 solution, 0.94; and (F) HC1 solution + pepsin 0.95. The correlation (0.19) between NVI and per cent DMD with (G) 0.01 N NaOH solution was not significant.