The study，in which two sheep were put on fast for eight days was carried out in order to investigate the effects of starvation on rumen liquid and amino acids of the blood serum.
1) The constituents of rumen liquid-VFA，ammonia，total nitrogen and total sugar contents，all decreased rapidly as the starvation intensified. The pH value of the rumen liquid went up approximately to 8.0 on the eighth day of the fasting.
2) The level of total free amino acids of blood serum didn't vary significantly throughout the starvation. That of rumen liquid，on the other hand， decreased rapidly and resulted in a tenth of the value of pre-experimental period on the fourth day of the fasting. The ratio of lysine and glycine increased but that of glutamic acid and alanine decreased in the blood serum as the effect of the starvation, while the ratio of glutamic acid, valine and isoleucine increased and that of lysine, aspartic acid and alanine decreased in rumen liquid.
3) As the result of the eight-day fasting the essential to non-essential amino acid ratio increased from 0.87 to 1.15 in the blood serum. However, no significant change of the ratio was observed in rumen liquid.