Polyamines in cow's and sow's milk.

There were considerably interspecies, individual, lactation and age related variabilities in the concentration of spermidine and spermine in cow's and sow's milk. Concentration of spermidine was similar in cow's and sow's milk, whereas spermine level was higher in sow's milk. The level of spermine was higher than spermidine throughout the lactation in sow's milk, whereas spermine in cow's milk was secreted only at the beginning of lactation (collostrum and milk of the first month of lactation). The peak of spermidine and spermine concentration occurred in the collostrum and milk between the 1st and 3rd week of lactation in cow and sow, respectively. There was a significant positive relationship between milk yield and spermidine secretion in cow as well as between the number of piglets and milk spermidine concentration in sow.