Slow Growing Pre-Weaning Piglets Have Altered Adipokine Gene Expression

Growth rate affects adipose tissue development and variations in growth rate may potentially impact adipokine expression. Samples of subcutaneous (SQ) and perirenal (PR) adipose tissues and longissimus muscle were collected at day 21 of age from the fastest and slowest growing piglets within seven litters. Reverse transcription and real-time PCR were used to quantify adipokine mRNA abundance. Leptin, adiponectin, tumor necrosis factor α (TNFα ) and lipoprotein lipase (LPL) mRNA abundance were lower in SQ from slow growing piglets (SGP) than in fast growing piglets (FGP, P < 0.05). Macrophage migration inhibitory factor and TNFα gene expression were reduced in PR from SGP in comparison to FGP (P < 0.05). Interleukin 1β (IL1β), IL15 and LPL were increased in the longissimus of SGP relative to FGP (P < 0.05). Analysis of mRNA abundance for these adipokines within adipose tissue at day 21 of age demonstrated that the effect of growth rate on adipokine expression varies among different adipokines and the internal and external sites of adipose tissue deposition (PR versus SQ). The increase in longissimus expression of LPL and IL15 suggests that nutrient partitioning for energy use may be greater in the skeletal muscle of the SGP.