Lactation delays the re-initiation of oestrous cyclicity in rats, resulting in physiological sterility for the duration of suckling. During this phase, the secretion of pituitary gonadotrophins is suppressed by an unknown mechanism. Continued application of the suckling stimulus by litter replacement (Bruce, 1958; Nicoll & Meites, 1959), or injections of prolactin (Meites & Nicoll, 1959), have ...

Artificial insemination program to increase production is affected by oestrus. Breeders generally identify cows in oestrus based on their behavior. Currently, can be predicted and scheduled due PGF2α synchronization. This study aims determine the detection of after synchronization, more specifically distinguish audio-visual The six used were synchronized using PGF2α. Descriptive methods include...

Ewes in which oestrus had been synchronised were artificially inseminated (at the second synchronised oestrus) 17 to 21 days after placement on plots containing either oestrogenic (Trifolium subterraneum L. c% Dinninup) or non oestrogenic pasture. A comparison of the reproductive performance indicated that grazing oestrogenic pasture prior to and during joining reduced the proportion of ewes in...

Ustuner B., U. Gunay, Z. Nur, H. Ustuner: Effects of Long and Short-Term Progestagen Treatments Combined with PMSG on Oestrus Synchronization and Fertility in Awassi Ewes During the Breeding Season. Acta Vet. Brno 2007, 76: 391-397. Synchronization of oestrus has been used to increase reproductive effi ciency in most animals, including ewes. The aim of the present study was to compare the effec...

To compare an injectable progesterone (MAD-4) with an intravaginal device (IPD), and natural O17 with synthetic oestradiol (OB) in a synchronisation protocol, 51 cows were divided into four groups. Each group was treated with one of the two sources of progesterone and one of the two oestradiol formulations. Oestrus behaviour, follicle diameter, and pregnancy rates were evaluated. Oestrus behavi...

This paper reviews the influence of social mechanisms on oestrus and sexual motivation in pigs. The social relations between the animals and the signals they send out can inhibit as well as encourage their social motivation. Social stimuli from both boars and other sows in oestrus tend to induce and synchronise oestrus and ovulation amongst sows. The courting behaviour of boars is also facilita...

The mating behaviour of 2 jacks, each with 21 non-pregnant jennies, was studied when the jennies were in natural oestrus and simultaneously induced oestrus. The main observations were: efficient pasture breeding at natural and induced oestrus, a territorial sociosexual structure, prolonged pre-copulatory interaction, gradual increase of mating activity up to 2 days before ovulation, a copulator...

myiasis is caused by the larvae of flies infesting animal or human tissues and organs. this report aims to present a case of pharyngeal myiasis caused by the larvae of oestrus ovis (diptera: oestridae). a 55-yr old drug addict living in the shahindeje village of western azerbaijan province, northwestern iran was referred to the emam reza hospi­tal in tabriz, having a medical history of chronic ...

Synchronization of bovine oestrous cycles was studied with respect to methods of accomplishment. A total of 328 cows were re¬ cycled by: {a) daily subcutaneous injections of progesterone, {b) larger subcutaneous injections every 3rd day and {c) corpus luteum expression. Standing oestrous was exhibited by 262 cows. Twelve did not exhibit oestrus and fifty-four exhibited symptoms but refused moun...

We have previously shown that administration of antiprogestin (AP) type II RU486 to ovariectomized (OVX) rats on the morning of pro-oestrus decreases the magnitude of preovulatory gonadotrophin surge. This suggests that the effect of RU486 on LHRH-dependent gonadotrophin release may be independent of its ability to block progesterone actions. The aim of the present research was to study the pos...