The objective of this study was to provide some data on concentrations of seminal plasma free amino acids (FAAs) in order to compare these values with different total contents of morphologically abnormal spermatozoa (MAS) in the semen of 37 experimental adult boars. The boars were kept in the same housing, feeding and breeding conditions. Immediately after collection, semen gel free volume, sperm concentration and total MAS were determined microscopically. The boars were divided into two groups (A − <i>n</i> = 24, B − <i>n</i> = 13) according to the significantly different total MAS content (<i>x</i>: A = 9.46 ± 4.95, B = 46.00 ± 14.54%, <i>P</i> < 0.01). Deproteinized seminal plasma samples (supernatant) were analysed for concentrations of 13 FAAs: Tau, Asp, Thr, Ser, Glu, Gly, Ala, Val, Met, Ile, Leu, Tyr and Lys by liquid chromatography (AAA 339 M analyser). A highly significant correlation was determined between total MAS and total FAA content in all experimental boars (<i>n</i> = 37, <i>r</i> = −0.60, <i>P</i> < 0.01). Glutamic acid was a predominant FAA in seminal plasma in both groups of boars (x: A = 28.49 vs. B = 17.60μM/100 ml) but its concentration was significantly higher in group A (<i>P</i> < 0.01). The proportion (%) of glutamic acid concentration in the total content of FAAs in both groups of boars was nearly equal (A = 38.1 vs. B = 38.9%, <i>P</i> > 0.05) as well as the proportion index of the individual FAAs calculated from glutamic acid (= 100%). The differences in the particular FAAs recorded between group A and group B were statistically significant for 11 out of the 13 FAAs observed (<i>P</i> < 0.05 and <i>P</i> < 0.01) in favour of group A as well as in the total calculated content of FAAs per boar (x: 74.70 vs. 45.23μM/100 ml, <i>P</i> < 0.01). A significantly negative relationship between the MAS content and the concentration of seminal plasma FAAs (<i>r</i> = −0.60, <i>P</i> < 0.01) is the main result of this study with regard to the markers for potential boar semen fertility estimation.
Seminal Plasma Free Amino Acids and Seminal and Blood Plasma Proteins of the Guinea Fowl (Numidia meleagris)