Ricerc@Sapienza

Metabolic profile of fresh turkey spermatozoa at three different reproductive period ages,
namely 32, 44 and 56 weeks, was monitored by Nuclear Magnetic Resonance (NMR) spectroscopy
and correlated to sperm quality parameters. The age-related decrease in sperm
quality as indicated by reduction of sperm concentration, sperm mobility and osmotic tolerance
was associated to variation in the level of specific water-soluble and liposoluble metabolites.
In particular, the highest levels of isoleucine, phenylalanine, leucine, tyrosine and
valine were found at 32 weeks of age, whereas aspartate, lactate, creatine, carnitine, acetylcarnitine
levels increased during the ageing. Lipid composition also changed during the
ageing: diunsaturated fatty acids level increased from 32 to 56 weeks of age, whereas a
reduction of polyunsaturated fatty acids content was observed at 56 weeks. The untargeted
approach attempts to give a wider picture of metabolic changes occurring in ageing suggesting
that the reduction of sperm quality could be due to a progressive deficiency in mitochondrial
energy producing systems, as also prompted by the negative correlation found
between sperm mobility and the increase in certain mitochondrial metabolites.