Martínez, S., Valera, L., Villodre, C., Madrid, J., Orengo, J., Tvarijonaviciute, A., Cerón, J. J. and Hernández, F. 2014. Effect of feeding on hormones related with feed intake in reproductive sows with different energy balances. Can. J. Anim. Sci. 94: 639-646. The different phases that occur during the reproductive life of the sow involve different energy balances, which can affect the levels of hormones that regulate appetite. This study analyzes the behaviour of serum insulin, leptin, ghrelin, cortisol and butyryl-cholinesterase, before and after feeding in pregnant, lactating and post-weaning sows. Hormones were analyzed in blood samples, which were collected after fasting overnight (0 min) and 30 min after feeding at day 109 of pregnancy, at day 9 post-farrowing and at day 3 post-weaning. Before feeding, insulin and leptin levels were not statistically different between reproductive stages. Feeding increased serum insulin and leptin levels of pregnant sows, increased insulin and decreased leptin levels in lactating sows, but had no effect on post-weaning sows. Deacylated ghrelin was higher in pregnant sows and acylated ghelin in post-weaning sows before feeding. Feeding intake did not affect the concentration of deacylated and acylated ghrelin in any group. Cortisol was positively correlated with acylated ghrelin before feeding in pregnant and lactating sows, and negatively with deacylated ghrelin before and after feeding in pregnant sows. There was a negative correlation between deacylated and acylated ghrelin before and after feeding in pregnant and post-weaning sows. So, sows with different energy balances had different insulin, acylated ghrelin and cortisol dynamics before and after feeding, suggesting that these analytes could be used as biomarkers to detect situations resulting in a poor energy balance in order to improve handling programs.