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This study assessed the value of ultrasonography in characterising bovine cystic ovaries and monitoring their responses to different treatments. Thirteen cows were diagnosed by ultrasonography as having luteinised ovarian cysts and seven were diagnosed as having follicular ovarian cysts. Six of the former were treated with prostaglandin, four with a progesterone intravaginal device (PRID) and three with gonadotrophin-releasing hormone (Gn-RH); five of the latter were treated with Gn-RH and two with a PRID. All the animals were re-examined by ultrasound and blood was collected for the measurement of plasma progesterone concentration at intervals until oestrus. The treatment of the luteinised cysts with prostaglandin caused marked decreases in size and plasma progesterone concentration and altered their echotexture within two to four days; oestrus occurred within three to four days. In two of the cows treated with a PRID the cysts regressed within one to two weeks but the other two cows required supplementary treatment with prostaglandin; oestrus and ovulation were observed only after the cysts collapsed. Gn-RH stimulated oestrus and ovulation within three to four days but the cysts did not collapse until much later. The treatment of the follicular cysts with Gn-RH or a PRID caused fresh ovulation and the formation of a corpus luteum but had little immediate effect upon the cyst. The plasma progesterone concentrations in some of the cows with either follicular or luteal cysts were similar on the day of treatment and were therefore of little value in differentiating the types of cyst.(ABSTRACT TRUNCATED AT 250 WORDS)

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Leydig cells are the major source of androgens in the male, and it is likely that these cells are also targets for androgen action. The role of androgen action in regulating the development of Leydig cell function has been determined using the testicular feminized (Tfm/Y) mouse, which lacks androgen receptors. In Tfm mice, the testes fail to descend at the normal time (25 days), and testicular descent was, therefore, surgically prevented in control (+/Y) animals. The activity of 3 beta-hydroxysteroid dehydrogenase increased during development from 5-40 days in control and Tfm mice, with no significant difference between the groups. In control animals, 17 alpha-hydroxylase activity was low from 5-25 days, at which time there was a 26-fold increase up to 40 days. In the Tfm group, 17 alpha-hydroxylase activity was 4-fold higher than that in controls on day 5, but showed no change in activity after 25 days and remained at neonatal levels up to 40 days. The activity of 17-ketosteroid reductase in the control animals showed a developmental pattern similar to that of 17 alpha-hydroxylase, with a marked increase in activity after 25 days. In the Tfm group, 17-ketosteroid reductase was normal on day 5, but failed to show any significant change thereafter and remained at neonatal levels on day 40. Serum LH levels in control animals increased from 5 days to a peak at 30 days. In Tfm mice, LH levels were significantly increased on days 20 and 40, but did not differ from controls on days 5, 25, and 30. In control +/Y animals, in which normal testicular descent was allowed to proceed at 25 days, the pattern of development was similar to that in the cryptorchid +/Y animals, although the increase in 17 alpha-hydroxylase activity at 30 and 40 days was significantly greater. The results show 1) that fetal Leydig cell steroidogenesis is enhanced in the absence of androgen receptors, but 2) that adult Leydig cells require receptor-mediated androgen activity around day 25 for normal functional development. In addition, 3) the lack of testicular descent at 25 days reduces the pubertal rise in 17 alpha-hydroxylase activity.

The physiological basis of seasonal breeding in the guinea fowl (Numida meleagris) still remains unknown, despite the socioeconomic importance of these birds, particularly in Ghana. A study involving a total of 50 local guinea cocks was conducted, and documented gross anatomical and histological differences in the reproductive organs of breeding and non-breeding male guinea fowls. The study also compared peripheral testosterone concentrations in breeding and non-breeding cocks. Seasonal differences in variables measured were determined using two-tailed t-test/Mann-Whitney U-test. All comparisons were made at 5% level of significance. Breeding males had significantly (P = 0.000) higher anatomical biometric parameters than their non-breeding counterparts. Also, breeding birds had thicker (P = 0.000) phalli than their non-breeding counterparts. Histologically, regressing testis was characterized by the presence of sloughed off cells and increased debris in the tubular lumen and within the excurrent duct system, collapsed tubules and reduction in tubular lumen. Germ and Sertoli cell populations and nuclear diameters and actual seminiferous tubular diameter and length in regressing testes were significantly (P = 0.000) lower than in active testes. Leydig cell nuclear diameters and populations were also significantly (P = 0.000) reduced. Relative volume of seminiferous tubules in the testis, testicular sperm production/mg testis and per testis and peripheral testosterone concentrations were all higher (P < 0.05) in breeding than non-breeding testis. The ducts in the epididymal region also saw significant (P < 0.05) reductions in luminal diameters in non-breeding birds. Significant regression in anatomical and histological structures of the guinea cock reproductive tract occurred during the non-breeding season, and lower peripheral testosterone concentrations may be responsible for this phenomenon.