Longitudinal ultrasound, behaviour and endocrine evaluations were conducted, over 14 to 18 months, in two young female Indian rhinoceroses (Rhinoceros unicornis) to characterize the oestrous cycle. Both females showed the same pattern of follicular development producing a large follicle (10-12 cm diameter) on one of the ovaries that persisted for 8.5 +/- 4.68 days before spontaneously ovulating...

Prairie voles (Microtus ochrogaster) typically stop breeding during winter. Male prairie voles respond to winter day lengths with gonadal regression, whereas female voles are relatively unresponsive to photoperiod. Unlike commonly studied laboratory rodents, female prairie voles do not exhibit spontaneous oestrous cycles. Instead, females are induced into oestrus by chemosensory cues from consp...

Disease and stress can disrupt the circadian rhythm of activity in animals. Sensor technologies automatically detect variations daily activity, but it remains difficult to exactly when disruption starts. Here we report a mathematical Fourier-Based Approximation with Thresholding (FBAT) method designed changes cows whatever cause change (typically disease, stress, oestrus). We used data from an ...

This study was carried out to determine the effect of repeated injections cloprostenol sodium during early luteal phase on luteolytic capacity and hormonal changes Large white x Pietrain in Otukpo. A total ten (n = 10) oestrus sows were randomly divided into two groups. experiment a control. Group I 5) no synchronizing agent administered II received 6 doses 500 µg at days 5, 6, 7, 8, 9 10 oestr...

Since structural luteolysis involves deterioration of tissue, the gene expression of matrix-metalloproteinase-1 (MMP-1) and the respective tissue inhibitor of this metalloprotease (TIMP-1) were measured at various times on the day of pro-oestrus and in animals in which the preovulatory prolactin surge was blocked for the duration of 3 cycles by bromocriptine. An additional group of prolactin-bl...

Changes in the genital mucus around the oestrus are used by different diagnostic methods to determine optimal fertilisation time. In the current study, the authors evaluated the different arborisation patterns found in vestibular mucus, and also established its relationship with vestibular resistance changes during oestrus. Thirty multiparous sows were checked by transrectal ultrasonography to ...

BACKGROUND Access to oestrus females tends to be the main driver of male sociality. This factor can lead to complex behavioural interactions between males and groups of males. Male bottlenose dolphins may form alliances to consort females and to compete with other males. In some populations these alliances may form temporary coalitions when competing for females. I examined the role of dyadic a...

In Préalpes de Sud ewes after an autumn lambing, the mean post-partum interval to first LH surge was 10 +/- 1 days and 17 +/- 1 days for non-suckling and suckling ewes, respectively. Post-partum interval to first luteal phase, estimated from plasma progesterone concentrations, was similar in non-suckling and suckling ewes (27 +/- 1 days and 28 +/- 5 days, respectively). Interval to first oestru...

Due to declining dairy cow fertility rates, there is great interest in developing tools for oestrus detection. Compounds in the volatile profile of oestrous cows are suggested as oestrus-specific, but consistent results have not been presented. Certain haematophagous arthropods can discriminate stages of the mammalian reproductive cycle based on host volatiles. This study investigated whether t...

Changes in plasma and follicular fluid concentrations of inhibin were examined in sows after weaning at 28-32 days post partum. From 0 to 48 h after weaning, inhibin concentrations were 200-300 times higher in follicular fluid from small (less than 4 mm) and medium-large (greater than or equal to 4 mm) follicles than in ovarian venous plasma. Inhibin concentrations increased in follicular fluid...