Male Ferrets Research Articles

Chromosome behaviour in the male ferret and mole during anoestrus

The breeding season of many Mammals is restricted to a relatively short period of the year. In such species usually both sexes exhibit a more or less well-defined seasonal variation in their reproductive organs. Several investigators have found that these variations in the male consist chiefly of alteration in the size of the testes and epididymis, accompanied by marked histological and cytological changes leading to a complete absence of sperms during the quiescent or anoestrous period. The cyclic histological changes in the testes and in the accessory organs have been described in detail in the ferret ( Putorius furo, L .) by Allanson (1932), and in the mole ( Talpa europea, L .) by Tandler and Grosz (1912) and Allanson ( unpublished ). It was found in both genera that during the breeding season spermatogenesis is complete and very active in the rapidly growing testis, but after that period the reproductive organs return to a quiescent state and sperms are entirely absent.

Litters from Ferrets in January Induced by Increased Exposures to Light After Nightfall

(1) Three ferrets were induced to come into oestrus in November, December and January by graduated increases in daily exposure to electric light after nightfall. (2) They were mated once each with males rendered sexually active in the same way, and two became pregnant, the other only pseudopregnant. (3) One of the pregnant females gave birth to a litter of six on January 14; the other died before parturition. (4) The birth of this litter indicates that both male and female ferrets, brought into sexual activity in winter by increasing exposures to light, are potent and fertile, and can produce young under conditions of temperature in which newly born ferrets were unable to survive. (5) In each of these females winter coat was shed, beginning about two weeks before the expiration of term, and summer or spring nursing coat was completed after the termination of pregnancy or pseudopregnancy. (6) It is suggested that numerous copulations within thirty hours may possibly cause luteinization of ovarian follicles...

Modification of mammalian sexual cycles. III. Reversal of the cycle in male ferrets (Putorius vulgaris) by increasing periods of exposure to light between October second and March thirtieth

Modification of mammalian sexual cycles. III. Reversal of the cycle in male ferrets (Putorius vulgaris) by increasing periods of exposure to light between October second and March thirtieth

Studies on the hypophysectomized ferret. IV.—Comparison of the reproductive organs during anœstrus and after hypophysectomy

In Part II (Hill and Parkes, 1932, b ) it was shown that hypophysectomy of the male ferret during the breeding season caused the testes to regress to a condition very similar to the found in the normal animal during anœstrus. This result suggested that decreased activity of the anterior pituitary body might be the causative factor in anœstrus. The hypophysectomized ferrets regressed from full activity to the anœstrous condition in about one month, i. e ., much more rapidly than the normal animal regresses at the end of the breeding season. This fact showed that hypophyseal activity diminishes gradually at the end of the breeding season and presumably reaches its lowest level when the testes are most atrophic in November. The next problem was to determine whether or not hypophysectomy during November leads to further regression, i. e ., whether the pituitary body is wholly or only partially inactivated at the extreme of the anœstrous period. We have now investigated this question, and also carried out similar experiments on the female.

Studies on the hypophysectomised ferret. II. - Spermatogenesis

Smith (1930) has shown that all parts of the reproductive tract of the male rat show pronounced atrophy after hypophysectomy. The testes are much reduced in size and are flabby. The seminiferous tubules show a corresponding diminution in size and all indications of spermatogenesis are absent. A more immediate effect of ablation of the pituitary gland is a complete loss of interest in the female. Richter and Wislocki (1930) also noted atrophy of the male genital organs of the rat after hypophysectomy, but in no great detail. Hypophysectomy has not yet been performed on a species in which the male shows a clear cut anœstrous period such as is found in the male ferret (Allanson, 1932). The present work was undertaken to find out if the testes of the ferret react to hypophysectomy in the same way as those of the rat, and to compare the resulting condition of the testes with that found during anœstrus. Further light on the activity of the pituitary body during anœstrus might thus be obtained. In addition, it was hoped to determine the rate of regression after hypophysectomy and to compare this with that found at the end of the breeding season. No attempt will be made in this or the following paper to deal with the general effects of hypophysectomy, but it may be mentioned that loss of body weight, if any, was slight during the time covered by these experiments.

The reproductive processes of certain mammals. III.—The reproductive cycle of the male ferret

Cyclic changes in the reproductive organs of male mammals have been studied in a few forms only, but the information available reveals interesting differences in the duration of reproductive activity, and in the correlation between the various organs. Marshall (1911) has described the reproductive cycle in the male hedgehog. Regaud (1904), Tandler and Grosz (1911) and Lecaillon (1909) have studied the mole, but with conflicting results. Rasmussen (1917 and 1918) gives detailed information of the periodic changes in the interstitial tissue of the testis in the woodchuck, and more recently Courrier (1923) has investigated the reproductive cycle in various bats, in the mole, hedgehog, and marmot. The work of Marshall (1904), Robinson (1918) and Hammond and Marshall (1930) has established that in the female ferret the breeding season is restricted and lasts from April to August ; during the remaining months of the year the reproductive organs are in a state of quiescent anœstrus. The first mating occurs in March or April. The present investigation was undertaken in order to determine the duration of the quiescent period in the male ferret and to compare the changes in the testis tubules with those in the interstitial tissue and accessory organs. The condition of the reproductive tract has accordingly been studied at various times of the year, and an attempt has been made to assess the changes in the organs and in their constituent parts.

Studies on the Sexual Cycle in Birds. VI. Effects of White, Green, and Red Lights of Equal Luminous Intensity on the Testis Activity of the European Starling (Sturnus vulgaris)

Studies on the Sexual Cycle in Birds. VI. Effects of White, Green, and Red Lights of Equal Luminous Intensity on the Testis Activity of the European Starling (Sturnus vulgaris)