Effects of maternal nutrition during gestation and lactation on muscles fiber types and fatty acid profile of suckling lambs

The aim of this thesis is to evaluate the effect of linseed supplementation in ewe during gestation and lactation, in muscle fatty acid profile and muscle fiber population. For this purpose 3 experiments are included in the thesis. The first experiment studied the effect of maternal omega3 supplementation during gestation in muscle fiber characteristics, chemical composition and fatty acid profile on muscle of newborn lambs. The result showed no effects of maternal omega3 supplementation on fetal growth and number of muscle fiber; the maternal diet influences the content of TFA, total PUFA, PUFA n-3 and PUFAn-6. In the second experiment was investigate the maternal omega3 supplementation both during gestation and lactation on muscles morphometric measurements and fiber population of suckling lambs at weaning. The treatment affected average weights of organs but did not influence the muscles development and in the number of total, type1 and type 2 fibers in the LD muscle. The maternal omega3 supplementation using linseed during gestation showed a depressing effect on lamb weight and daily gain. The continuous linseed supplementation during gestation and lactation restores the growth performances of lambs. The third experiment aimed to evaluate the effect of maternal omega3 supplementation during pregnancy and early lactation on the fatty acid profile of LD and ST muscles and brain tissue. Results showed an increase of the VA, c9t11 CLA and ALA in muscles without change the long chain fatty acid EPA and DHA .The elongase and desaturase indexes evidenced that the efficiency of conversion of ALA into their long metabolites in skeletal muscles of lambs is very low both during fetal growth and during the first month of life.