For the majority of dairy herds where artificial insemination (AI) is practiced, the limiting factor toward obtaining efficient reproductive performance is the failure to detect oestrus in a timely and accurate manner. Periodic visual observation has been the dominant method used to identify cows in oestrus. New approaches are being developed to provide automated systems of detection of oestrus...

The present study was conducted to investigate the attributes of ram sexual behaviour under different social conditions. Six intact rams and eight overiectomized ewes were used in this experiment. Ewes were artificially brought into oestrus. All mating traits were recorded every 10 sec during a 1 h mating session under five social conditions viz., ram exposed to single oestrus ewe, ram exposed ...

To determine the change in distribution of ewes exhibiting oestrus at the first and second oestrous cycles after progestagen treatment, data were examined from six experiments in which 430 ewes received progestagens but experienced no fertile mating at the first post-treatment oestrus. Three progestagens, three breeds and two seasons were involved. In all experiments there were more silent heat...

Efficient oestrus detection is important economically, particularly with seasonal-calving herds employing artificial insemination, as every missed oestrus effectively costs 21 days milk production for that cow in that season which is about 8% of the total. Traditionally, oestrus detection relies mainly on visual observation of animal behaviour a cow in oestrus will stand and allow herself to be...

AIM To compare the sensitivity, specificity, predictive values and accuracy of detection of oestrus using a novel oestrus detection strip (ODS) and a camera-software device (CSD) with typical farm management practices of visual observation and use of tail paint in dairy cattle at pasture. METHODS Dairy cows (n = 480) in a seasonal-calving herd managed at pasture under typical commercial condi...

Progesterone action is mediated by its binding to specific receptors. Two progesterone receptor (PR) isoforms (PRA and PRB), three membrane progesterone receptor (mPR) subtypes (mPRalpha, mPRbeta and mPRgamma) and at least one progesterone membrane-binding protein [PR membrane component 1 (PRmc1)] have been identified in reproductive tissues and brain of various species. In the present study, w...

The distribution of sialic acid residues as well as other glycosidic sugars has been investigated in the horse oviductal isthmus during anoestrus, oestrus and pregnancy by means of lectin and pre-lectin methods. Ciliated cells and non-ciliated (secretory) cells exhibited different lectin binding profiles that were found to change during the investigated stages. Ciliated cells did not show any r...

Rats ovulate during the 1st or 2nd night following parturition (Hoffman & Schwartz, 1965). Subsequently, oestrus is not usually observed during lactation. After weaning, cycling is resumed and only then can oestrus be discerned (Long & Evans, 1922). The possibility of studying the relation between lactation and fertility is, therefore, conditional on effective mating of the females at the post-...

American black bears (Ursus americanus) are seasonally polyoestrous and exhibit delayed implantation, which may allow equal and independent fertility of recurrent oestruses of a mating season. We postulated that the luteal inactivity during delayed implantation allows bears to have sequential ovulation during a polyoestrous mating season such that each oestrus of a polyoestrous female will have...

the objective was to quantify and compare cow cervical morphology on oestrus vs. non-oestrus daysusing a new farm technology. the cervical tissues were videotaped using a cervixscope involving newcamera equipment in four holstein cows on multiple oestrus and non-oestrus days to score tissue morphology as altered by oestrus. the non-oestrous days were in diestrus phases. the videotaped records w...