Pozo Verde Natural Reserve is an integrated farm located in the Cauca Valley Province in Southwestern Colombia at 950 metres above sea level. The main production systems found in the farm are described as follow: 
1. Pig production: 73 breeding sows and 595 growing and fattening pigs distributed in three separated buildings. 
2. Double Purpose Cattle: 166 F1 (Holstein * Zebu) and F2 (H*Z x H*Z) animals divided in four groups. 
3. Buffaloes: 52 buffaloes used for milk and beef production and as a source of animal draught. 
4. Forage production: Composed of star grass areas (Cynodon nlemfuensis), areas with mixed star grass and pizamo tree (Erythrina fusca), protein banks including E. fusca, Giant taro (Alocasia macrorhiza) and Trichanthera gigantea, and an area with sugar cane, as well as eight ponds for Azolla spp. and Salvinia sp. production. 
5. Organic matter recycling: 300 m² of Eisenia foetida for processing cattle and buffalo manure and other solid residues. Two 75 m³ and two 14 m³ plastic bag biodigesters. 

Pigs are mainly fed with a prepared ration based on corn and soybean meal, but pregnant sows receive also Azolla spp., Salvinia sp. and Giant taro (Alocasia macrorrhiza) as a source of protein that can replace up to 50% of commercial feed.

The main source of feed for cattle and buffaloes are the pastures. However they remain confined during part of the day or overnight in order to feed them with a supplementary ration (sugarcane, tree foliage and chicken litter) and to recover the manure. 

The solid fraction of the manure equivalent to 230 ton/year for cattle and 37 ton/year for buffaloes is used for worm production (Eisenia foetida) and the buildings washed and the wastewater used for biogas production in two 75 m³ plastic bag biodigesters. 

Pig manure in the raising and fattening section, equivalent to 1883 kg/day is treated also in the biodigesters. The wastewater from this production is 25 m³/day. 

In the pregnant sows section, the solid fraction of the manure (133 kg/day) is collected before washing the building using 2.5 m³/day of water. 

Biodigesters provide biogas for heating the piglets from birth up to 60 days (51 burners * 14 hours/day) and for replacing part of the fuel in a combustion engine that provides electricity to the farm. The biodigester slurry is collected in a basin and pumped to the grasslands and crops in the farm.
This integration has allowed the farm to eliminate the use of chemical fertilisers, to increase milk and beef production and to reduce production costs due to the savings in electricity, feed and fertilisers. In addition, water pollution is highly reduced since all the wastewater is processed and used in the farm. 

Julian Chará works as coordinator of the Aquaculture and Recycling Group at CIPAV Foundation (Centre for Research in Sustainable Systems of Agriculture) in Cali, Colombia. His background is in Animal Production with a M.Sc in Sustainable Development of Agriculture and other in Aquaculture. Currently he is a Ph.D. Student at the Institute of Aquaculture, University of Stirling, U. K..
At CIPAV he has contributed to the development of the Productive Water Decontamination System that uses a plastic tube biodigester, aquatic plant channels and agriculture for treating wastewater from livestock production and households.
Subject areas of particular interest include biogas production, fish polyculture and integrated aquaculture.

Elkin Dario Pulido
Fundación CIPAV. Carrera 35A Oeste # 3-66, Cali Colombia. 
E-mail: elkin@cipav.org.co

Mr Pulido has a degree in Veterinary and Animal Husbandry and has been working during the past two years as assistant researcher with the Aquaculture and Recycling Group of CIPAV. His main areas of interest are Energy and organic matter flow evaluation in sustainable systems of agriculture.

Miss Cuellar works as a CIPAV researcher at "Pozo Verde" Natural Reserve in Jamundí municipality, Colombia. During the last seven years she has given technical and scientific advise in the Natural Reserve monitoring the different subsystems and contributing to the integration of activities. Her background is in Animal Husbandry with an M.Sc. degree in Sustainable Agriculture from the Wye College at London University. Her main areas of interest are: Animal welfare and behaviour, Pig production and Double purpouse cattle.