Brazilian Santa Inês (SI) sheep are very well-adapted to the tropical conditions of Brazil and are an important source of animal protein. A high rate of twin births was reported in some SI flocks. Growth and Differentiation Factor 9 (GDF9) and Bone Morphogenetic Protein 15 (BMP15) are the first two genes expressed by the oocyte to be associated with an increased ovulation rate in sheep. All GDF...

Variation in ovulation rate of ewes was studied with particular reference to the heterosis effect in a 3-breed (Dorset Horn, South Australian Merino, Corriedale) experimental sheep population. For the population as a whole, heterosis effect on the young (1 1/2 year-old) ewes (+0.17 k 0.06** ova, or 14.5%) was similar to that on the mature (5 1/2 year-old) ewes (+0.19 f 0.06** ova, or 12.5%), in...

There is evidence that the ovulation rate (number of ovulations per ewe ovulating) of successfully teased ewes was increased relative to that of their second ovulation or relative to spontaneously ovulating flock mates. The effect was observed in Merino, Prealpes and Ile-de-France breeds and may have been prevented in ewes primed with progestagen before the introduction of rams (Oldham and Cogn...

The acute effects of short-term glutamate administration on the number of antral follicles and ovulation rate were examined in adult goats. Neither live weight (44.5±1.3 kg) nor body condition (3.3±0.8 units) differed between the control (untreated) and glutamate-treated (0.175 mg/kg) animals (p>0.05). However, the number of antral follicles (3.4 vs. 2.1, p=0.05) and ovulation rate (2.5 vs. 1.5...

In normal production practices, sows and gilts are inseminated at least twice during estrus because the timing of ovulation is variable relative to the onset of estrus. The objective of this study was to determine if a normal fertilization rate could be achieved with a single insemination of low sperm number given at a precise interval relative to ovulation. Gilts (n=59) were randomly assigned ...

Background: To evaluate the effect of metformin on ovulation and pregnancy rate in clomiphene citrate resistant women with polycystic ovary syndrome (PCOS). Material & Methods: In this clinical trial each patient, regarding her previous resistance to Clomiphene, served as her own control. A total of 35 clomiphene citrate resistant PCOS patients, referring to Royan institute were studied. Clomip...

The aim of this work was to evaluate the effect of different doses of eCG administered subcutaneously (0, 50 and 200 IU) and the hormonal induction of ovulation (GnRH or hCG) on embryo recovery and in vitro development of embryos post-vitrification in two selected lines of rabbit does. The two selected lines were line V (selected for the litter size at weaning) and line R (selected for growth r...

Plasma follicle-stimulating hormone (FSH) was evaluated in gilts from two studies in which ovulation rate was increased through direct selection for number of corpora lutea (CL) to determine whether selection for ovulation rate affected FSH secretion during prepubertal development. In the first study, 76 control and 110 selected gilts of University of Nebraska gene pool lines were bled twice du...