PSIII-A-11 Effects of Maternal Nutrition and Selenium Status on Postnatal Muscle Growth and Meat Quality

Abstract

Abstract To investigate the effects of maternal nutritional plane and selenium (Se) level on offspring muscle development in first parity ewes, Rambouillet ewes (n = 84) were stratified by BW and randomized to receive diets formulated to contain adequate Se (ASe) or high Se (HSe) initiated at breeding. On d 40 of gestation, ewes were assigned randomly within Se treatments supply 60% (RES), 100% (CON), or 140% (HI) of NRC requirements. Offspring were slaughtered at 180 ± 2.2 d of age. Psoas major (PM), longissimuss dorsi (LD), and semimembranosus (SM) samples were snap frozen and analyzed for fiber diameter and type, celluarity, calpain 1 autolysis, and calpastatin expression. Within the PM RNA was increased (P=0.04) in HSe vs. ASe and CON vs. HI. Protein was greater (P=0.05) in ASe than HSe within HI. RES had greater (P=0.09) protein than CON. Calpain 1 had more autolysis in HSe vs. ASe (P≤0.03) in CON and HI. Calpastatin with lower molecular weights was greater (P≤0.01) in the Ase than HSe from CON. Within the SM, ASe had greater (P≤0.05) DNA and RNA concentrations than HSe within HI. Calpastatin immunoreactivity was less (P=0.04) for RES-ASe than all treatments except CON-HSe. Within the LD, calpain 1 had more (P≤0.01) autolytic degradation in CON-ASe than other treatments. Maternal diet did not influence fiber type or diameter. The influence of treatments on skeletal muscle cellularity and calpain system activation is not consistent between muscle types. The PM was most influenced by selenium in the HI group. Conversely, the LD showed more activation of calpain in the CON-ASe. Maternal diet and selenium possibly changed muscle development in offspring which could result in altered quality and yield of lamb produced.