. . . . . . . . . . . "A comparison of alternative manure management systems effect on the environment, total energy requirement, nutrient conservation, and contributions to corn silage production and economics" . "A comparison of alternative manure management systems effect on the environment, total energy requirement, nutrient conservation, and contributions to corn silage production and economics"@en . . . "A comparison of alternative manure management systems : effect on the environment, total energy requirement, nutrient conservation, and contributions to corn silage production and economics"@en . . . .