This paper reports reproductive parameters for 9 female grey-cheeked mangabeys kept in a captive colony over a 17-year period. Birth seasonality has shown a consistent trend towards an autumn peak. Oestrous cycles had an average length of 31.2 days: however 'short-cycle' (29.9 days) and 'long-cycle' (37.7 days) groups could be discriminated. Gestation was 175 days, with little variability. Vari...

In the present study we tested whether regulation of the metabolome in bovine oviductal fluid depended on the stage of the oestrous cycle, the side relative to ovulation and local concentrations of steroid hormones. Luminal fluid samples from both oviducts were collected in the preovulatory, postovulatory, mid- and late luteal phases, from cyclic cows at a local abattoir (18-27 cows per stage a...

The purpose of the study was to localise neuropeptide Y (NPY) immunoreactive (ir) neurons in the hypothalamus during two phases of the oestrous cycle in the ewe. Hypothalamic tissue was collected from Polish Merino ewes (n=8) in the follicular (15th day) and preovulatory (17th day) phases of the oestrous cycle. NPY-ir neurons were detected in the hypothalamus using immuohistochemistry followed ...

Gonadotropins are protein hormones secreted by the pituitary gland and include luteinizing hormone (LH) and follicle stimulating hormone (FSH). Both LH and FSH govern the estrous cycle i.e. the cyclical pattern of ovarian activity that facilitates the transition of female animals between periods of reproductive non-receptivity to receptivity enabling mating and subsequent pregnancy. The onset o...

Several authors have recently demonstrated the luteolytic action of exogenous prostaglandin F2\g=a\(PGF2\g=a\)in various laboratory and domestic animals and there is now ample evidence that PGF2\g=a\is the uterine luteolytic hormone which terminates the life of the CL in many species (McCracken, 1972; McCracken, Carlson, Glew, Goding, Baird, Gr\l=e'\en & Samuelsson, 1972). In cattle, Rowson, Te...

Ten field and laboratory experiments were conducted in which Merino ewes were treated with one or two 125pg injections of Cloprostenol, an analogue of prostaglandin F2a (PG). All treatments commenced in the luteal phase of the oestrous cycle. Sixty-six percent of ewes were detected in behavioural oestrus within 64 hr of completion of treatments although 95% of all treated ewes ovulated in appar...

Previous research has shown that the proportion of seasonal anoestrous ewes that ovulate in response to the introduction of rams ('ram effect') is dependent upon pheromonal and sexual behavioural stimuli emitted by the rams. Close contact with oestrous ewes is likely to increase the rams' libido and level of testosterone secretion, which in turn has been suggested to positively influence the pr...

Norepinephrine, dopamine, and serotonin concentrations in the hypothalamus and stalk-median eminence were estimated in nine Hereford heifers at the onset of oestrus or 48 hr later. Significant differences in levels of monoamines at these stages of the oestrous cycle were not evident. Norepinephrine levels were similar in the hypothalamus and the stalk-median eminence, but dopamine and serotonin...

The aim of this study was to characterise the follicular dynamics in first two oestrous cycles peripubertal Malabari goats. Transrectal ultrasonography carried out on alternate days after observed oestrus. Follicular studies revealed presence five wave with predominant three and four patterns. interwave interval for ovulatory longer than preceding waves cycles. diameter largest follicles 1 larg...