Some Amino Acid Aspects of Bovine Semen

Correlation between fertility and levels of protein, sugar and free amino acids in seminal plasma of Nelore bulls

“…The free amino acid with the highest concentrations in all samples was the glutamic acid, followed by glycine and alanine, comprising 60.5% of the total. Similar results were reported by Roussel and Stallcup (1967), Al-Hakim et al (1970) and Sexton et al (1971) in bovines and by Smith and Graham (1972) in sheep. All of them observed that the glutamic acid was the most abundant amino acid in the seminal plasma.…”

“…No correlations between the levels of the 17 types of free amino acid measured in the seminal plasma and the fertility of the bulls were observed (Table 2). Oltjen et al (1971) and Roussel and Stallcup (1967) did not find such correlation either, but showed that high amounts of total free amino acids are important for the semen quality and the fertility of the animal. Al-Hakim et al (1970) verified a linear correlation between glutamic and aspartic acids and fertility of Holstein bulls.…”

“…The 17 free amino acids analyzed were also studied by Roussel and Stallcup (1967) and Sexton et al (1971) in Holstein animals, while Al-Hakim et al (1970) found 20 free amino acids. Smith and Graham (1972) also found the same 17 amino acids in the seminal plasma of rams and Hernvan et al (1986) detected 19 amino acids in the seminal plasma of men.…”

“…They are produced in the testes, epididymis and sex acessory glands and also by action of endogenous proteolytic enzymes on seminal proteins after ejaculation (Roussel and Stallcup, 1967). No direct relationship between seminal plasma free amino acids and fertility has been observed, except for glutamic acid that, together with aspartic acid, serine, alanine and glycine, constitute the largest portion of free amino acids in this fluid (Roussel and Stallcup, 1967).…”

A comparative study on the composition and importance of free amino acids in semen of gilthead sea bream, Sparus aurata, and perch, Perca fluviatilis

“…In the male reproductive organs of mammals, free amino acids are secreted by the testes (Setchell et al 1967), by the epididymis, and by the accessory glands and originate by the proteolysis of seminal fluid proteins after ejaculation (Roussel and Stallcup 1967). Glutamic acid, aspartic acid, serine, alanine, and glycine constitute the largest portion of free amino acids in mammalian seminal fluid (Roussel and Stallcup 1967) and are up to eight times those in blood.…”