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RESULTS

CBC'S of the ten animals all fell within, or on the periphery of the range of norms for swine (Table 1). The research animals consisted of pigs ranging in age from approximately one to seven years. All animals came from the same area on Malo Island. Upon first observation (Table 2), the hormonal values of the representative samples cannot by themselves be interpreted. The ratios of estradiol to testosterone were generated and the following general conclusions may be drawn. Ratios greater than unity have been generally designated as female and those less than one generally designates maleness(27).Like the two normal males, all seven of the intersexes showed ratios less than 1.0. These observations seem to support the theory that Vanuatu's intersexual pigs are actually mal-developed boars. Pig "B", said by locals to be a pregnant female, showed a progesterone level of 10.6 ng/ml, consistant with that of a pregnant sow.

The results of the Dihydrotestosterone (DHT) test on the sera of pigs D,E,F,J,K,L,M were consistent with maleness. Of the 54 animals on which external examinations were conducted, there was a high degree of variability, the most common occurrences were in testicular (number, size, and location) and urogenital configuration. Findings for the intersexes varied from very "female" looking external genitalia with no testicles to a descended scrotal sac containing two large well-developed testicles. Within this range were many different testicular presentations including an empty scrotal sac, one degenerate descended testicle, one large testicle, and one large and one small testicle represented. Of the animals examined, 61% or 33 animals exhibit no testicles whatsoever, 10 (or 19%) possessed 2 well-formed scrotal testicles, 8 (or 15%) had 1 normal descended testicle, and the remaining 5% had 1 small and 1 large or 1 small testicle present. As the intersexes' testicular development approached that of the "normal male" condition, there was a corresponding change in the position and length of the ventral labial commissure (V.L.C.) and the urogenital aperture. When there were no testicles or scrotum present, the vulva seemed almost undifferentiable from that of the normal female organ except possibly for a slight reduction of the urogenital opening, and the presence of the corpus cavernosum (C.C.) may push the (V.L.C.) dorsally and laterally. The terminal end of the urethra is distinguished from the corresponding structure of the normal female by the presence of the bulbo-cavernosus. Correspondingly, as the testicles become larger and descend into the scrotum, the V.L.C. appears to become larger as the C.C. itself enlarges and begins to turn ventrally, taking the V.L.C. with it. The most developed phase that was examined was that of the "transitional" male pseudohermaphrodite in which two large testicles were situated in the scrotum and the projection, now much longer than before, consisting of the V.L.C., the C.C. and the terminal end of the urethra, was situated directly anterior to the scrotum. Despite all of these varying phases of genital development, each of these animals, as an adult, consistently exhibited tusks, with a base diameter consistent with that of the male of the species. As expected those animals exhibiting 1 external testis (whether it appeared normal or degenerate) also contained 1 degenerated testicle within the abdomen. In one case, however, a young animal(Pig A) with no external testicles or scrotum, possessed only 1 small but well-formed testis inguinally. No vestige of the other testicle was detected. In most cases, the testicles appeared to be more or less degenerate or totally so. The vulva had a reduced urogenital aperture. There were never any rudiments of vagina, cervix, uterus, oviduct or ovaries evident in any of the intersex pigs examined, which concurs with Baker's findings in 1928(4).The urine was delivered from the bladder via the urethra to the external opening anteriorly corresponding with its specific phase of intersexuality. At the terminal end of the urethra there was a bulbo-cavernosus muscle which aids, in normal males, in expulsion of urine or sperm. In all cases, the internal anatomies were wholly male, although in various stages of development. Seminal vesicles, bulbo-cavernosus muscle, and corpus cavernosus were evident in every individual. Bulbo-urethral glands were found in all but one individual.

Table 1

Descriptions of ten Malo Island pigs selected for blood and skin biopsy examination (ages and wights are approximate).
ID SEX AGE (Yrs) WT (Kg) COLOR LOCALE DESCRIPTION OF EXTERNAL GENITALIA
B F (Preg) 4 37 Black Avunatari Normal female
C M 5 41 Black Avunatari Normal male
N M 3.5 46 Black Avunatari Normal male
D INTERSEX 1 14 Black Avunatari Two large testicles in scrotum; VLC approx. 1.3 cm. projecting dorsally and posteriorly.
E INTERSEX 7 70 Black with white legs Avunatari No testicles; scrotal sac evident; VLC approx. 1.9 cm long, pointing ventrally; urinates just dorsal to VLC projection.
F INTERSEX 1 16 Black Avunatari One normal testicle and one small in scrotum; VLC approx. 1.3 cm pointing dorsally and laterally.
J INTERSEX 5.5 82 Black Avunatari Hills One large testicle descended in sac. VLC approx. 2.5 cm long pointing ventrally.
K INTERSEX 3.5 76 Black Avunatari Hills One small testicle in scrotum. 1.9 cm VLC projection beginning to point ventrally.
L INTERSEX 3 34 White Avunatari Hills No testicles, no scrotum. Approx. 1.9 cm VLC pointing out and ventrally.
M INTERSEX 1.5 16 Brown and red Avunatari One large testicle in sac 1.3 cm VLC projection.

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Table 2

Analysis of blood hormone levels in ten pigs from Malo Island.
PIG ID SEX AGE DHT (ngm/ml) ESTRADIOL (pgm/ml) TESTOSTERONE (ngm/ml) Ratio ESTRADIOL to TESTOSTERONE
B Female (pregnant) 4   301 .16 1.88
C Male 5 2.27 255 4.81 .053
N Male 3.5 6.96 163 11.7 .056
D Intersex 1 .48 43 .89 .048
E Intersex 7 .79 25 2.78 .048
F Intersex 1 2.86 147 3.38 .043
J Intersex 5.5 4.74 138 6.39 .021
K Intersex 3.5 6.24 292 2.37 .123
L Intersex 3 2.87 309 2.88 .107
M Intersex 1.5 2.34 9 1.8 .005

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