BROWN MIDRIB-3 VERSUS NORMAL CORN PLANTS (Zea mays L.) HARVESTED AS WHOLE PLANT OR STOVER AND FROZEN FRESH OR PRESERVED AS SILAGE FOR SHEEP

Abstract

Brocr, E., Mulr-rn, L. D. eNo Kn.utn

Effects of a Brown‐midrib corn hybrid on nutrient digestibility in wethers and on dry matter intake, performance, rumen and blood variables in dairy cows

“…Consistent with the present results, reduced contents of lignin in Bm‐mutants in relation to isogenic variations and to common corn silage hybrids have been described frequently (Muller et al., ; Block et al., ; Greenfield et al., ; Qiu et al., ; Kung et al., ). Corresponding to the results above, however, the literature is inconsistent concerning differences between Bm‐hybrids and common hybrids regarding NDFom and ADFom contents (Muller et al., ; Block et al., ; Greenfield et al., ; Qiu et al., ; Kung et al., ).…”

“…Differences between groups were not significant, but live weight tended to be higher for Con‐fed animals; therefore, DMI should be referred to live weight. Dry matter intake per kg of live weight and DMI per kg of metabolic live weight did not differ between Con and Bm in Trials 1 and 2, which has been shown for wethers (Block et al., ) and heifers (Ballard et al., ). Greenfield et al.…”

“…It remains, however, unclear why CP digestibility was lower in Bm. An increase in digestibility of the fibre fractions of Bm‐corn silage was reported for wethers and lambs, (Muller et al., ; Block et al., ) and dairy cows (Sommerfeldt et al., ; Greenfield et al., ). Muller et al.…”

“…() and Block et al. () concluded that the lower lignin content allowed for a faster digestion of cell wall constituents (CWC). Sommerfeldt et al.…”

“…It was assumed that improved fibre digestibility was based on a reduced lignin content (Block et al., ) and/or changes in the structure of lignin (Sommerfeldt et al., ), while the increase in DMI could be a result of the improved fibre digestibility (Oba and Allen, ). The increase in performance may be based on the increase in DMI or digestibility or both (Oba and Allen, ; Ebling and Kung, ).…”