Regresar

Relationship between peptide YY, cholecystokinin and fermentation products in fasted, re-fed and ad libitum fed broiler chickens

Abstract:

The objective of the present broiler study was to study the relationship between peptide tyrosine-tyrosine (PYY), cholecystokinin (CCK) and short-chain fatty acids (SCFA) in the blood and caecal contents, and whether a period of fasting followed by reintroduction of feed influences this relationship compared with an ad libitum fed control. A total of 72 male broilers with 37-days of age (Ross 308) were randomly distributed into two experimental groups, with continuous illumination. Group 1 (n = 36) were fasted for 12 h followed by re-feeding, and Group 2 (n = 36) were feed ad libitum. Twelve animals per group were sacrificed immediately prior to reintroduction of feed to the fasted animals (T0h), and this was repeated at 3 h (T3h) and 6 h (T6h) after feed reintroduction. Blood samples were collected for PYY and CCK analyses, and short-chain fatty acids were analysed in blood and caecal contents. For PYY and CCK, the interactions between the feed administration, ad libitum or fasted, and the time after feed reintroduction were significant (P < 0.05). Peptide YY and CCK levels remained constant with time for the ad libitum fed animals. For fasting animals the highest PYY concentration was observed at T0h and it gradually reduced at T3h and T6h compared to ad libitum fed animals. Cholecystokinin levels were lower at T0h compared with the later time points in re-fed birds resulting in values similar to those observed in the ad libitum birds by T6h. Lower concentrations of butyrate in the caecal contents were observed in fasted animals at T0h, and this increased once the animals had access to feed. Peptide YY and CCK levels responded in an inverse manner to one another after fasting for 12 h, and both returned to levels similar to the ad libitum fed birds after 6 h re-feeding. These changes were accompanied by changes in butyric acid in caeca contents but not in blood.