Ecological footprint of different laying hen production systems in San Jeronimo municipality Antioquia, Colombia

In recent years, fish production has increased worldwide due to population growth and consumer interest in this type of product, proving an increase in the waste generated, with concomitant negative impact on the environment. Ecological footprint methodology is one of the sustainability indicators most used for assessing process environmental impact. This technique quantifies the effect of anthropogenic activities on the environment concerning water, forest products, infrastructure and carbon footprint, providing integral, comparable and reliable results. In this study, the environmental impact generated by taking advantage of red tilapia (Oreochromis Spp.) viscera to produce chemical silage and its implementation in the feeding of laying hens was determined, using the ecological footprint methodology as an indicator of sustainability. The productive system consisted of a red tilapia (Oreochromis ssp.) production farm located in the municipality of San Jerónimo, Antioquia (Colombia). The productive variables of the laying hens, laying percentage, egg weight and feed conversion ratio were evaluated. This chemical silage production process generates a reduction of 1.493 kg of CO2 per month compared to that generated by fresh viscera and are discharged into shallow dumps. Additionally, the main categories that generate the greatest impact on the production system are the use of natural resources and wastewater disposal. On the other hand, the productive variables of laying hens of the Isa Brown breed were not significantly affected by the inclusion of chemical silage at the 95% significance level, maintaining the percentage of laying and improving feed conversion. It was concluded that the use of fish by-products to produce feed for laying hens generates a reduction in the environmental load when compared to conventional waste disposal processes (landfill disposal). Red tilapia (Oreochromis Spp.) viscera chemical silage can be used as an alternative protein substitute in feeding laying hens for improved production performance. Key words: Ecological footprint, fish waste, layer hen, chemical silage, wastewater