Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: December 13, 2002
Publication Date: March 17, 2003
Citation: SALFEN, B.E., CARROLL, J.A. ENDOCRINE RESPONSES TO SHORT-TERM FEED DEPRIVATION IN WEANLING PIGS. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT. 2003. v. 81(Suppl.2):Abstract p. 63. Technical Abstract: Our objective was to determine endocrine responses to a short-term (24 h) feed deprivation period in weaned pigs. Eight crossbred male pigs were weaned at 18 d of age and placed on a complex nursery diet. At 4 d post-weaning, pigs were non-surgically fitted with an indwelling jugular vein catheter. Pigs in the feed deprived group (FD; n=4) had feed removed 5 d post-weaning, and feed was returned 24 h later. Control pigs (Con; n=4) were allowed ad libitum access to feed. Blood samples were collected at 0 h, 6 h, 12 h, 24 h and 30 h for determination of ghrelin (GR) and IGF-I. Four sub-samples were collected at each time point at 15 min intervals. Body weights (BW) of pigs were determined at weaning, 21 d of age and after the 30 h time point (24 d of age). There was a time X treatment difference in BW (P<0.05). FD pigs gained less weight throughout the experiment than Con pigs (0.67 +/- 0.34 vs. 0.32 +/- 0.16 kg; P<0.06). There was no difference in serum GR or IGF-I among the four sub-samples (P>0.90), therefore the means of the sub-samples were utilized for statistical analysis. Serum GR at 0 h tended to be different between treatments (P=0.06), therefore GR concentrations of each pig at various time points were expressed relative to 0 h. There was a time X treatment effect on GR concentrations (P<0.01). Serum GR in FD pigs tended to decrease 12 h compared to Con pigs (P=0.08). Relative concentrations of GR increased from 12 h to 24 h (P<0.01) and remained elevated through the 30-h time point in the FD treatment, but remained unchanged at all time points in Con pigs (P=0.91). There was a time X treatment effect on IGF-I (P<0.001). Serum IGF-I fell throughout the experiment and was lower in FD pigs at 12 h, 24 h and 30 h compared to Con pigs (P<0.05). Serum IGF-I increased following the return of feed at 30 h compared to 24 h (P<0.06). IGF-I concentrations rose throughout the study period in Con pigs (P<0.01). These results indicate that serum GR and IGF-I are influenced by short-term feed deprivation in weanling pigs.