Vle CONG. INTERN. REPROD. ANIM. INSEM. ARTIF., PARIS, 1968, VOL. I

Pig

The literature on intersexes in the pig suggested that
the majority are male pseudohermaphrodites with an XX sex chromo-
some constitution (Biggers and McFeely, 1964). Table 3 shows
the cases which have now been studied in respect to their sex
chromosomes. It is clear that a significant proportion are gene-
tic females which have developed testes.

The occurrence of freemartinism in pigs has largely been
a matter for conjecture, being based on seven cases of inter-
sexuality described by Hughes (1927, 1929) and one case des-
cribed by Hoadley (1928) . The argument is based on the simul-
taneous observation of fused placental circulations and inter-
sexual conditions in the foetuses. Recently another case has
been described by Benoit (quoted by Bruere, et al., 1968) in
which an intersexual foetus was observed whose placental clrcu=
lation anastomozed with the circulations of sibling male foetus.
There is now limited cytogenetic evidence which indicates that
the freemartin condition does occur in pigs. McFee, Knight
and Banner (1966) have cultured the blood leucocytes of an
intersexual pig, and found 90% had XX sex chromosomes and 10%
had XY sex chromosomes. Unfortunately the genetic sex of other
tissues was not determined. A further case of a male pseudo-
hermaphrodite has now been described by Bruere, Fielden and

Hutchings (1968), in which cultures of blood leucocytes had 91%

cells with XY sex chromosomes. Sex chromatin studies on neurones

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