The present investigation was carried out to evaluate the effects of environmental factors on reproductive performance of bovine (Bos taurus) during summer, winter and spring for one year. The study was performed on free moving animals under natural condition during the two consecutive estrus periods by visual observation. The duration of estrus, numbers of mounts were observed. There was a sea...

The objectives of the present study were to determine if lameness, a model for a natural chronic stressor, affects hormone concentrations in milk prior to estrus and/or the subsequent expression of estrus in the postpartum period. Dairy cows>20 days postpartum were scored for lameness and observed for estrus intensity using a weighted scoring system (>100 points=estrus=Day 0). Increasing lamene...

An experiment was conducted to investigate the changes in peripheral plasma FSH concentrations in relation to expression of estrus in Sahiwal cows. Out of total five estrus, three were accompanied by overt signs whereas rest two were silent estrus. In cows with overt estrus, plasma FSH concentrations during periestrus, early luteal, midluteal and late luteal phase were 1.65+/-0.34, 1.67+/-0.21,...

To investigate uterine and serum Ca++ and Mg++ variations during the estrous cycle in the bovine, 66 genital tracts and blood samples were collected from Urmia abattoir, Urmia, Iran. The phase of the estrous cycle was determined by examination of the structures present on ovaries and uterine tonicity. Of the collected samples, 17 were pro-estrus, 12 estrus, 14 metestrus and 23 diestrus. The ute...

Eighty crossbred, virgin, yearling beef bulls were subjected to three serving capacity (SC) tests. Ten low SC (LSC) and 10 high SC (HSC) bulls similar in weight (avg wt = 452 kg), testicular size and seminal traits but differing in average services were selected. Objectives were to evaluate the mating behavior and fertility of LSC and HSC bulls at pasture when exposed to an average and a heavy ...

Coyotes (Canis latrans) are seasonally monestrous and form perennial pair-bonds. Breeding is dominated by each pack's alpha male and female, and both sexes share responsibility for territory defense and pup-rearing. They are also opportunistic predators on domestic livestock and pets. But while dominant adults have been implicated as primary killers, depredation is reduced when coyotes are with...

On d 0 of the experiment Bos indicus x Bos taurus (n=130) cows received an injection of GnRH and a progesterone-releasing device called an Eazi-BreedTM CIDR® for 7 d with a prostaglandin F2a injection at CIDR removal. Upon CIDR removal cows were divided into two AI treatments: 1) injection of estradiol cypionate (ECP) 24 h after CIDR removal with AI 8 to 10 h after a detected estrus and timed-A...

BACKGROUND Pampas deer, Ozotoceros bezoarticus (Linnaeus 1758), is a South American grazing deer categorized as "near threatened". However, knowledge about pampas deer behavior including courtship and mating is scarce and incomplete. The aim of this study was to characterize the courtship and mating behavior of the pampas deer (Ozotoceros bezoarticus), an endangered species from South America. ...

Estrus detection in mares using contextually congruent stallion vocalization playback with and without stallion scent K.M. Janson, S.M. McDonnell ∗ Havemeyer Equine Behavior Laboratory, University of Pennsylvania School of Veterinary Medicine, Department of Clinical Studies, New Bolton Center, 382 West Street Road, Kennett Square, PA 19348, USA

Most mammalian females possess classic estrus, a discrete phase of the ovulatory cycle during which females engage in sex and undergo dramatic physical changes that make them attractive to males. By contrast, humans engage in sexual activity throughout the ovulatory cycle. But is it the case that humans possess no estrous-like changes across the cycle? Research over the past three decades has s...