An additional case of fertile bovine heterosexual twin female with sex-chromosomal chimerism (XX/XY)
A Holstein-Friesian female born as twins to a male showed sex chromosomal and blood type chimerisms; the ratio of XX/XY was 63/87 in a total of three examina-tions at different times; incomplete hemolysis was detected for antigenic factors in the B, C, L and S systems of blood type. Nevertheless, she attained sexual maturity and repeat-ed almost regular estrous cycles. By rectal palpation, no abnormality was found in the internal genitalia. The serum levels of estrone, estradiol-17 β and progesterone changed according to the stages of estrous cycle. She was artificially inseminated and successful conception was achieved.