Processing cereal straws by steam explosion in a pilot plant to enhance digestibility in ruminants.
Wheat, barley and oat straws were treated by steam explosion (SE) and then washed with 50g/l NaOH solution. The SE treatment was optimized at batch scale on the basis of carbohydrate recovery. Stocks of fodder (300kg) were produced at 198 degrees C for 2.5min by a continuous reactor and used for in vivo digestibility tests carried out on sheep. The flow-sheet and the mass balances were obtained for the entire process. For the three straws, the water consumption has been 7.3kg/kg of straw. To delignify and improve the digestibility of the straws, 20g of NaOH/kg straw was used. The yield of fodder, lignin and hemicellulose is dependant on the nature of the starting straw. Delignified fodder (insoluble fraction) can be produced with a yield of 0.64, 0.59, 0.55, respectively, from wheat, barley and oat straw. SE improved the digestibility of the straw by 25%; alkaline washing further increased it by 9%. Balanced rations containing, on a DM basis, 1/4 of treated straw, had digestibility coefficients similar to those of commercial rations based on alfalfa.
Viola
E
E
ENEA, Italian Agency for New Technology, Energy and Environment, Biomass Section, cp 1, 75025 Policoro (MT), Italy. viola@trisaia.enea.it
Zimbardi
F
F
Cardinale
M
M
Cardinale
G
G
Braccio
G
G
Gambacorta
E
E
D000818:Animals; D004063:Digestion / Q000502:physiology*; D002523:Edible Grain / Q000737:chemistry* / Q000378:metabolism*; D005260:Female; D005511:Food Handling / Q000379:methods*; D005524:Food Technology / Q000379:methods*; D008297:Male; D010865:Pilot Projects; D018547:Plant Stems / Q000737:chemistry / Q000378:metabolism; D012418:Ruminants / Q000502:physiology; D012756:Sheep / Q000502:physiology*; D013227:Steam
D013227:Steam