The reproductive endocrinology of the highly endangered numbat (Myrmecobius fasciatus) is described for the first time. Patterns of faecal steroid secretion (progesterone [PM], oestradiol-17β [E2] and testosterone [TM] metabolites) were examined within a captive numbat population over 1 year and revealed a highly synchronized seasonal pattern of reproduction. TM secretion increased progressivel...

A meta-analysis was conducted to summarize the results of studies which have described the profiles of hormones during the oestrous cycle in buffalo using a fixed effect model and a random effect model. Plasma progesterone concentrations were lowest (0.30±0.06 ng/ml) during the peri-oestrous phase and increased (p = 0.067) through the early luteal phase to a maximum concentration (1.94±0.03 ng/...

The existence of short ovulatory cycles (5-day duration) after the first male-induced ovulations in anovulatory ewes and goats, associated or not with the appearance of oestrous behaviour, is the origin of the two-peak abnormal distribution of parturitions after the "male effect". We propose here a working hypothesis to explain the presence of these short cycles. The male-effect is efficient du...

The oviduct undergoes changes under the influence of steroid hormones during the oestrous cycle. However, the molecular mechanisms underlying oviductal regulation are not fully understood. The aim of the present study was to identify the gene expression profile of the porcine oviduct in different stages of the cycle using microarray technology. A systematic study was performed on animals at fou...

In the normal oestrous cycle of the female house mouse, a true luteal phase is absent. Some unknown stimulus provided by the male during mating induces the luteal phase of the oestrous cycle in the female. Land & McGill (1967) initiated a search for this stimulus. They recognized three possible sources of stimulation from the male that might be either sufficient or necessary for the induction o...

Difficulty in observing oestrus is a problem for many dairy farmers performing AI. Finding ways to synchronize oestrous cycles or strengthen display of oestrus without hormonal treatments would be of great interest because many consumers object to the use of exogenous hormones on healthy animals. Modification of reproductive cycles through chemical communication has been reported in several spe...

Ovarian follicles are a major site of oestrogen synthesis in sheep, but almost nothing is known about the relative contribution made by follicles of different sizes to the output of oestrogen at various stages of the reproductive cycle. To determine this, ovaries were dissected from sheep, all follicles over 2 mm in diameter were explanted separately as organ cultures and the daily production o...

Elephantulus rufescens is one of 15 species of elephant-shrews (F. Macroscelididae), a specialized group of mammals confined to the continent of Africa (see Rathbun, 1979, for review). Since elephant-shrews have only recently been successfully bred in captivity (Rathbun, Beaman & Maliniak, 1981), information on their reproduction has largely been obtained from examination of the reproductive or...

Three experiments were conducted to evaluate factors affecting number of surface ovarian follicles and oocytes yield and quality in buffalo. In Experiment 1, ovaries (n = 126) were collected in pairs from slaughtered anoestrus, early pregnant and cyclic buffaloes. Ovarian follicles (1-3, 4-9 and > or = 10 mm diameter) were counted, aspirated and oocytes were recovered and evaluated. In Experime...