You raise a question that cannot be answered by a short response. To help you think through some of the critical issues associated with management of the animal manure, you might consult this Livestock and Poultry Environmental Stewardship curriculum which was recently developed by a national team of experts from around the United States. While it focuses on environmental and materials-handling issues from a North American perspective, it walks you through most of the critical issues that should be considered. You may need to consider those discussions from a perspective of what is most important in your part of the world.
One word of advice: Do not treat manure as a waste product. This is a mistake that many U.S. producers have made for the past two generations. The organic and nutrient value of animal manures provides more than ample reason to treat manure as a valued resource. With the rapidly rising costs of commercial fertilizers, those animal and crop producers who can utilize manure as a resource are gaining substantial economic and environmental advantage over their neighbors who are managing manure as a waste product.
Consider systems that conserve the organic and nutrient value of manure for later use in crop production or other recycling opportunities. In the United States, manure's value as an agronomic resource is superior to its value as an energy resource or to its management as a waste product.
However, there is value in manure treatment systems that replace energy imports to your farm and should be investigated. Overall, the best system would capture energy from the manure, allow for retention of nutrients for crop use, and provide a product that can be recycled such as bedding while being economical feasible to implement.
Author: Rick Koelsch, University of Nebraska
