Effects of different roughage sources and feeding period on adipogenesis of sheep preadipocytes

Abstract

The objective of the present study was to conduct an adipogenic evaluation of different roughage sources and feeding period during sheep preadipocyte differentiation.  Seven Suffolk wether sheep (3-4 months of age) were used in this study.  Six wether sheep were divided into a timothy hay feeding group (TH, n＝3) and an Italian ryegrass straw feeding group (IR, n＝3) for 11 months of feeding period.  The both forages were offered to the animals at 2% BW (dry matter (DM) basis), and concentrate was fed at 40% of forage intake (as fed basis).  The both diets were offered to achieve 100 g of daily gain (DG).  A single sheep was used for preadipocyte isolation.  Sheep serum samples collected on the 4 and 11 months of feeding period of each dietary treatment were added to an adipogenic induction medium for differentiation of preadipocytes derived from sheep subcutaneous adipose tissue.  The cytoplasmic lipid accumulations in the TH serum-treated preadipocytes were significantly higher than those of the IR-serum treated preadipocytes on day 7.  Messenger RNA expression of PPARγ, C/EBPα, aP2 and LPL were up-regulated by TH serum treatment.  This study shows that timothy hay diets can up-regulate adipocyte differentiation in adipose tissue of young sheep.