Journal of Animal Science and Veterinary Medicine

Monosodium glutamate (MSG) is a sodium salt of glutamic acid, popularly known as (Ajinomoto) and indiscriminately consumed as a flavour enhancer in various foods. The consequences of Monosodium glutamate consumption on semen characteristics and sperm morphology remain unknown. This study aimed to investigate the effects of MSG on semen characteristics and sperm morphology. Sixteen (16) mature bucks weighing between 10 and 14 kilograms were randomly assigned to four groups (A-D) of four bucks per group. Group A served as the control, while B, C and D served as the treatment groups and received graded doses of 0.25, 0.50 and 1.0 g/kg of the MSG salt at 48 hours intervals for 28 days respectively. Semen was collected from all the groups at the second- and fourth weeks post-treatment using the electro-ejaculation method. The semen was evaluated using light microscopy. The mean semen volume and percentage of progressively motile sperm cells significantly reduced (p<0.05) at four weeks post-treatment in groups B, C and D compared to the control group. Mean sperm count significantly reduced (p<0.05) in group D two- and four weeks post-treatment while the mean percentage liveability only reduced in group D four weeks post-treatment. The significantly observed abnormal sperm morphology was bent mid-piece and curved tail in groups B, C and D, two- and four weeks post-treatment. The total proportion of abnormal cells was less than the acceptable 20%. The sperm volume, sperm motility and sperm morphology reduced across the groups as the dosages of MSG increased. Hence, monosodium glutamate adversely affects semen characteristics; impairs sperm fertilizing ability and may reduce bucks’ fertility. Thus, its continuous application as a condiment in various foods and administration to breeding bucks should be used with caution.