Effects Of Intrauterine Growth Restriction During Late Pregnancy On The Growth And Development Of Ovine Fetal Muscle And Perirenal Adipose Tissue

This study investigated the effects of intrauterine growth restriction during late pregnancy on the growth and development of ovine fetal muscle and perirenal adipose tissue.42Mongolian ewes in their second or third parity, which had similar live weight (mean53.28±4.87kg) were mated at a synchronized oestrus.6ewes were slaughtered at the beginning of the experiment and the remaining36animals were allocated to three different groups:Restricted Groupl (RG1,0.175MJME kgw-0.75d-1, n=14), Restricted Group2(RG2,0.33MJME kgw-0.75d-1, n=12) and Control Group (CG, ad libitum,0.67MJ ME kgw-0.75d-1, n=10). At140d of gestation,6representative ewes in each group were slaughtered, and their fetal longissimus dorsi muscle, semitendinosus, biceps, arm triceps and perirenal adipose were dissociated. The results indicated:(1) With the reducing of maternal energy levels during late pregnancy, the fetal weight, daily growth rate were significantly decreased in restricted groups.(2) With the decrease of maternal nutrition level, the fetal carcass weight, carcass compositions weight, Longissimus dorsi muscle, Semitendinosus, Biceps and Arm triceps weight were significantly decreased. The fiber density of Longissimus dorsi muscle and Arm triceps were significantly increased, but the area and diameter were significantly reduced. For fetal Semitendinosus and Biceps in RG2and RG1groups, the fiber density were significantly declined(3) As the decrease of maternal nutrition levels, the perirenal adipose weight, total DNA content in mitochondria, UCP1gene expression in perirenal adipose were reduced and the protein concentration in mitochondrial and Leptin gene expression n perirenal adipose were increased. The perirenal adipose structure was modificated.