Effects of fodder beet on rumen metabolism

Abstract

ABSTRACTTwo experiments were carried out with sheep, to characterize fodder beet in terms of its effects on rumen function. In experiment A, a study was made of the effects of supplementing hay with fodder beet (FB) on rumen pH and volatile fatty acid (VFA) concentration compared with two control supplements of either barley/maize (BM) or molassed sugar-beet shreds (SBP). Hay was offered with all three supplements in a 50: 50 ratio on a dry matter (DM) basis. The mean rumen pH for the fodder beet diet was 6·34 and intermediate between two controls (BM 6·20 and SBP 6·38). There was no significant difference in rumen concentration of total VFA for the three different diets (FB, SBP and BM) but there were highly significant effects due to diet for acetic and propionic acid molar proportions (P< 0·001). Molar proportion of propionic acid for diets FB, BM and SBP were 0·2064, 0·2221 and 01880 respectively. The loss of DM from nylon bags incubated in the rumen of sheep given the test diets was 471, 447 and 486 g/kg for FB, BM and SBP respectively. In experiment B, the rate ofin saccoorganic matter (OM) disappearance of the three supplements were compared in sheep given a constant high forage diet (900 g/day hay DM + 200 g/day compound food DM). There were highly significant differences in rates of OM disappearances for the supplements (P< 0·001). The losses of OM measured after 3 h incubation in the rumen were 767, 608, 378 and 236 g/kg for fodder beet, barley/maize, molassed sugar-beet shreds and hay respectively.