In this study, semen samples from 25 bulls that had passed a breeding soundness evaluation were analyzed for the presence or absence of a 31-kDa protein, known as fertility-associated antigen (FAA), on spermatozoal membranes. Eighteen bulls had FAA on sperm (FAA-positive) and seven were devoid of FAA on sperm (FAA-negative). A single ejaculate from each bull was extended and frozen with 25 to 3...

Estrus is induced in female gray short-tailed opossums (Monodelphis domestica) by exposure to male chemical signals (pheromones). Isolated females remain anestrous, but direct exposure to a male or his scent-marked cage induces estrus within 4-6 days. The objective of this study was to investigate the importance of the vomeronasal organ in detection of and response to estrus-inducing pheromones...

Numbers of estrus synchronization programmes are available in cattle based on the use of various hormones like progesterone, prostaglandin F2a and their various combinations with other hormones like estrogen and Gonadotrophin Releasing hormone (GnRH). Selection of appropriate estrus synchronization protocol should be made on the basis of management capabilities and expectations of the farmer. S...

Rats display strong behavioral rhythms during the ovarian cycle. During estrus, food intake is minimal due to a decrease in meal size, and locomotor activity is maximal. To investigate how activity influences feeding patterns across the ovarian cycle, we used a computerized system to monitor spontaneous meal patterns in intact, cycling female rats with and without access to running wheels. We f...

Long-acting GnRH agonists have been used both for canine estrus induction and prevention. The objective of the study was to investigate the use of a deslorelin implant as a long-term and reversible contraceptive in prepubertal bitches with special regard to the time of epiphyseal closure. Thirteen healthy, crossbreed, medium-sized prepubertal female dogs were used in this study. An implant cont...

The administration of PMS:HCG proved satisfactory as a method for synchronizing estrus and ovulation in sows after 3 or 6 weeks of lactation and permitted artificial insemination at one time without relying on the detection of estrus. Fifty-eight Duroc sows were assigned randomly as controls or to a hormonal-treatment group when their litters were weaned at 3 or 6 weeks of age. Twenty-nine sows...

two experiments were performed to determine the effectiveness of different progestogens contained in intravaginal devices, different doses of ecg and subsequent hcg treatment on the reproductive performance of estrus-induced mature lori ewes. in the first experiment, 88 ewes were allocated into two groups, and were treated with either fluorogestone acetate (fga) sponges or controlled internal d...

There are advantages for use of frozen-thawed boar sperm (FTS) as a tool for preservation and transfer of valuable genetic material, despite its practical limitations. It was hypothesized that increasing the number of motile FTS and number of fixed-time artificial inseminations (AI) would improve pregnancy rate and litter size. Semen from six boars was frozen in 0.5mL straws at 500x10(6)cells/m...

Tamilnadu is known for domestication of farm animals and home of many recognized sheep breeds, among them, Ramnad white is one of the breed of hardy and best suitable for the migratory system of rearing which were declining due to cross breeding. To retain the indigenous breed, many assisted reproduction technologies were used, but most of them are failed due to the detection of accurate estrus...

A randomized complete block design was used to compare the effects of feeding melengestrol acetate (MGA) at 0.4 (0.4M) and 0.5 (0.5M) mg/d per head on feedlot performance, estrus activity, and carcass characteristics of commercial beef heifers (n = 1,418; 10 pens/ treatment). Within 48 h of arrival at the research site, heifers were assigned to treatment, processed according to feedlot protocol...