Egg transfer experiments have consistently failed to find differences among sheep breeds in their ability to support a given number of fertilised eggs. The literature on egg survival rate in pregnant, multiple ovulating ewes is also remarkably consistent across a wide range of breeds and environments in terms of the ratio of foetuses (or lambs) to corpora lutea. Two reports on egg survival in e...

background: intracytoplasmic sperm injection (icsi) is an advanced technique employed in assisted reproductive clinics for treatment of infertile couples. the reproductive endocrinologists try their level best to identify factors that enhance success rate after icsi. objective: to compare estradiol progesterone ratio on ovulation induction day amongst pregnancy outcome groups following icsi. ma...

BACKGROUND Religious (halachic*) infertility' results from precoital ovulation prior to immersion in a ritual bath (mikveh) 7 days after menstruation, as mandated by Jewish religious law. Previous authors recommended treatment with estradiol to postpone ovulation and enhance pregnancy rates. OBJECTIVES To evaluate the prevalence of halachic infertility in an ultra-Orthodox jewish community, a...

Fifty-five microsatellite markers were scored in an F2 population of pigs (n = 114 females) developed at the University of Nebraska. The population was produced by crossing a line previously selected for 10 generations using an index of ovulation rate and embryonal survival and a line selected at random. The lines were from a common base population and differed by 6.7 ovulations and 3.1 fetuses...

Direct selection for litter size was compared with selection for ovulation rate, ova success, or uterine capacity and for indexes of ovulation rate with ova success or uterine capacity. Selection was simulated for 10 generations in a mouse population based on a model integrating ovulation rate, potential embryonic viability, and uterine capacity. Two indexes including ovulation rate (OR) and ov...

A selection experiment was established in 1981 to increase twinning rate in cattle. Results reported are through 1993 calf crops. Estimates of genetic parameters for a two-trait twinning and ovulation rate model with genetic groups were as follows: heritabilities of .03 for twinning and .07 for ovulation rates with a genetic correlation of nearly 1.00 and fractional permanent environmental vari...

Nine generations of selection for high ovulation rate were followed by two generations of random selection and then eight generations of selection for increased litter size at birth, decreased age at puberty, or continued random selection in the high ovulation rate line. A control line was maintained with random selection. Line means were regressed on generation number and on cumulative selecti...

The study evaluated a seminal effect on the ability to induce ovulation of a synthetic GnRH analogue, buserelin acetate, administered by vaginal mucosa in rabbit does. In a first experiment, 751 receptive nulliparous and multiparous non-lactating does were randomly assigned to groups of different seminal doses (6, 12, 24, 50, and 100 million total sperm in 0.5 mL). All seminal doses contained 5...

Background: The objectives of a series of studies undertaken was to improve farm animal reproductive efficiency in terms of embryo production efficiency, conception rate and litter size by immunoneutralization of inhibin in conjunction with other conventional reproductive techniques. Materials and Methods: A recombinant porcine inhibin alpha-subunit mature peptide was produced by mass scale and...

ETEROSIS in characteristics which are part of the reproductive process is a commonly observed result of crossing unrelated stocks in many species (e.g., GOWEN 1952). In mammals, the observed heterosis in litter size could be due to superiority of the crossbred in ovulation rate, in embryo survival, or both. The second of these parameters can be further subdivided into preand postimplantation st...