Thesis (M.Sc.)--Chulalongkorn University, 2006

The objectives of the present study were to measure the concentrations of serum progesterone and faecal progestins in non-pregnant and early pregnant female Asian elephants and to study the relationship between both hormones. The experiment included 6 non-pregnant and 5 pregnant elephants. Blood and faecal samples were collected weekly for 1 year starting from the first week of the behavioral estrous. The faecal progestins were extracted and analyzed using enzyme immunoassay (EIA). Serum P[subscript 4] were analyzed using I-radioimmunoassay (RIA). The statistical analyses were performed using Analysis of variance and Spearman' correlation. This study found that the oestrus cycle was 14.1+2.4 weeks (mean+SD). Mean serum P [subscript 4]concentration differed significantly between pregnant and non-pregnant elephants (0.56 versus 0.08 ng/ml, P<0.001) and the serum P[subscript 4] in pregnants were significantly higher than non-pregnant elephants after the 13th week post mating (0.09 versus 0.03 ng/ml, P=0.05) The concentrations of serum P[subscript 4] and faecal progestins were significantly correlated both in non-pregnant (r=0.32, P=0.004) and pregnant Asia (r=0.33, P<0.001). However, the individual's correlation coefficient varied between animals from (r=-0.086, P0.001). However, the individual's correlation coefficient varied between animals from r=-0.086 to r=0.88. A high variation among individual elephants in the faecal progestin data suggest more individuals and times need to be examined. The serum P[subscript 4] was more accurate than the faecal progestins. The serum P[subscript 4] could be used to predict early pregnancy in female Asian elephant.