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The physiological status of sows change during their productive live. The different phases of their reproductive life (pregnancy, lactation and post-weaning) involve important changes in the energy balance and hormone levels that regulate appetite. Sow health depends on the body’s ability to regulate appetite and metabolism, which are under the global control of circulating hormones such as insulin, ghrelin and leptin. This study analyzed the behaviour of serum insulin, leptin, ghrelin, cortisol and butyryl-cholinesterase, in sows before and after feeding in the different phases of their reproductive life.
In this study were used twenty-eight multiparous sows (Large White x Landrace), parity range from 3 to 4. In each phase, diets contained 12.2, 12.9 and 12.2 MJ of metabolizable energy (ME)/kg in pregnant diet, lactating diet and post-weaning diet ad libitum, respectively. 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. Sows with different metabolic states are associated with hormonal changes.
In post-weaning phase, there is an energy deficiency, insulin levels do not increase after feed intake when the concentrations of acylated ghrelin and butyrylcholinesterase are high. However, in pregnant sows with positive energy balance, leptin increases after feed intake. As a result, insulin, ghrelin and leptin could be used as biomarkers resulting in a poor energy balance in order to improve handling programs.
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. doi:10.4141/CJAS-2014-018