Feeding value of whole-crop wheat silage for ruminants related to stage of maturity and cutting height.
Wheat was harvested five times during maturation, ranging from the middle of the milk stage to the transition to yellow ripeness (YR, cutting height of 10 to 12 cm), and ensiled. At the last two stages of maturity, the plants also were cut at 34 to 36 cm. The effect of stage of maturity on digestibility of dietary OM by sheep fed at maintenance was modest, but significant (linear effect, P < 0.01, silage mean 69.4%). Voluntary intake of OM was affected differently by increasing stage of maturity: it first declined but then rose as wheat reached the YR stage (quadratic effect; P < 0.10, silage YR + 28 g/kg body weight). The energetic feeding potential, calculated as the voluntary intake of digestible OM, was not affected by stage of maturity or by cutting height (P > 0.1). When the proportion of stem decreased, OM digestibility increased by 2 to 3 percentage units, but voluntary intake was not changed (P > 0.1). Digestibility of crude fibre decreased, and digestibility of NDF and ADF tended to decrease with increasing stage of maturity (68 to 63%, 62 to 59% and 58 to 55% respectively), whereas the cell wall fractions analysed at the level of single sugars showed no distinct changes. In contrast, decreasing the proportion of stem increased the digestibility of all cell wall fractions except galactose and arabinose. Based on available information about the conservation problems associated with later stages of maturity, wheat should be harvested for whole-crop silage at the beginning of the dough stage with a normal, low cutting height.
Mannerkorpi
P
P
Institute of Animal Nutrition, Physiology and Metabolism, University of Kiel, Germany.
Brandt
M
M
D000818:Animals; D001066:Appetite; D001835:Body Weight; D004043:Dietary Fiber; D004063:Digestion; D008297:Male; D009753:Nutritive Value; D012418:Ruminants; D012756:Sheep; D012820:Silage; D014908:Triticum / Q000254:growth & development; D015430:Weight Gain