Abstract
Thirty nine pregnant Javanese thin-tail ewes (20 and 19 carried a single and multiple [2 to 3] fetuses, respectively), and six nonpregnant ewes as controls were used to measure maternal serum hormone and blood metabolite concentrations as predictors of number of fetuses carried during pregnancy. Serum hormones (progesterone, estradiol, triiodothyronine, and cortisol) and blood metabolites (b-hydroxy butyric acid [BHBA], and blood urea nitrogen [BUN]) were determined every four weeks during pregnancy and were used to predict litter size by discriminant analysis. The results of data analysis indicated that serum progesterone and estradiol concentrations at weeks 8, 12, 16 of pregnancy could be used to predict the number of fetuses carried with precision of 86.7 to 95.6%. Serum triiodothyronine, cortisol, BHBA, and BUN concentrations during pregnancy, however, were not good predictors of the number of fetuses carried. Serum progesterone and estradiol concentrations as early as 8 weeks of pregnancy in sheep could predict the number of fetuses carried with 86.7% precision.