A TWO‐STAGE TECHNIQUE FOR THE <i>IN VITRO</i> DIGESTION OF FORAGE CROPS

TLDR

A simple technique for determining the in‑vitro dry‑ or organic‑matter digestibility of 0.5 g dried forage samples is described. The method incubates the samples first with rumen liquor and then with acid pepsin, and has been applied to assess digestibility of plant‑breeding material, leaf and stem fractions, and animal‑consumed herbage. Regression of known in‑vivo digestibility on in‑vitro dry‑matter digestibility produced Y = 0.99 X – 1.01 (SE ± 2.31), showing a strong linear relationship.

Abstract

A simple technique for the determination in vitro of the dry‐ or organic‐matter digestibility of small (0·5 g) samples of dried forages is described. It involves incubation first with rumen liquor and then with acid pepsin. Using 146 samples of grass, clover and lucerne of known in vivo digestibility ( Y ), the regression equation Y = 0·99 X– 1·01 (S.E. ± 2·31) has been calculated, where X = in vitro dry‐matter digestibility. This technique has been used for the study of the digestibilities of plant breeder's material, of the leaf and stem fractions of herbage and of herbage consumed by animals.