Postnatal Changes In Low Birth Weight Piglets Fed A High-Energy Diet

Postnatal growth is reduced in low (LBWT) compared with normal (NBWT) birth weight piglets. Our data suggest that weight gain and fat and protein deposition are lower in LBWT compared with NBWT piglets, despite feeding equivalent amounts of the same diet. The objective of this study was to investigate growth performance, body composition, and glucose clearance in LBWT and NBWT piglets when dietary energy supplies were increased. Day old piglets (n=6) were fed either low (LE) or high‐energy (HE), isonitrogenous diets containing 80% or 100% of metabolizable energy requirements. Body composition was determined using dual energy x‐ray absorptiometry before and 11 days after initiation of feeding. Fasting intravenous glucose tolerance test (IVGTT) was administered on days 1 and 13 of the study. At termination of the experiment muscles and visceral organs were weighed. Increasing dietary energy did not significantly increase growth rate of LBWT or NBWT pigs, however LBWT pigs were consistently lower than those in the NBWT group (P<0.05). Final fat and lean mass increased in both NBWT and LBWT piglets regardless of diet (P<0.05). Liver and longissimus dorsi weights as a percentage of whole body weight were higher in piglets fed a HE compared to those fed LE diet (P <0.05). There were no differences in glucose clearance across all groups. In conclusion, increasing dietary energy does not promote growth of LBWT or NBWT piglets, in large due to an increase in digestive organ weight.