One-hundred and twenty-three ewes were used in three experiments designed to determine whether the regulation of estrus, by administration of either prostaglandin F2 a (PG) to regress corpora lutea or medroxyprogesterone acetate (MAP) to control the length of the estrous cycle, would increase sperm death in the reproductive tract at the ensuing estrus. Ewes were treated either with PG injected ...

Hair sheep ewes were used to evaluate the influence of various levels of mating stimuli on the duration and timing of estrus and LH concentrations around estrus. Ewes were treated with PGF2alpha (15 mg, im) 10 d apart. At the time of the second PGF2alpha treatment (Day 0) ewes were placed in groups and exposed to different types of mating stimuli. One group of ewes (n = 16) was exposed to an ep...

BACKGROUND Raw ewe's milk, as used to manufacture Serra da Estrela Protected Designation of Origin cheese, was pre-treated by high pressure processing (HPP), using previously optimized conditions (121 MPa for 30 min), aiming evaluate its effect on milk technological properties subsequent cheese production, namely the impact resulting curd, whey and throughout ripening. RESULTS The yield increas...

The production of luteal oxytocin in ewes, resulting from the intrajugular injection of 200 micrograms of PGF2 alpha, could be determined by the increase in intramammary pressure. This simple indirect method of measuring the activity of the corpus luteum enabled easy detection of renewed post-partum ovulation or the onset of pregnancy. The response was monitored every two days between Days 0 an...

In the context of the recent pandemic threat by the worldwide spread of H5N1 avian influenza, novel insights into the mechanism of ligand binding and interaction between various inhibitors (zanamivir – ZMV, oseltamivir – OTV, 2,3-didehydro-2-deoxy-N-acetylneuraminic acid – DANA, peramivir – PMV) and neuraminidases (NA) are of vital importance for the structure-based design of new anti-viral dru...

To examine effects of nutritional plane and Se supplementation on colostrum quality and mammary development, individually fed, pregnant Rambouillet ewe lambs were allotted randomly to 1 of 6 treatments in a 2 x 3 factorial arrangement. Main effects included dietary Se level, which began at breeding (d = 0) [adequate Se (9.5 mug/kg of BW) vs. high Se (81.8 mug/kg of BW)], and plane of nutrition,...

BACKGROUND Elevated non-esterified fatty acids (NEFA) concentrations in non-pregnant animals have been reported to decrease pancreatic responsiveness. As ovine gestation advances, maternal insulin concentrations fall and NEFA concentrations increase. Experiments were designed to examine if the pregnancy-associated rise in NEFA concentration is associated with a reduced pancreatic sensitivity to...

The metabolic effects of a phlorizin-induced drainage of glucose were studied in six lactating ewes with or without peroral alanine drenches in a study of crossover design. Phlorizin gave rise to a small, but significant, elevation of plasma beta-hydroxybutyrate. The plasma level of alanine decreased by about 30% due to the phlorizin injections and alanine was negatively correlated to beta-hydr...

this experiment was conducted to determine the reproductive performance of kurdi ewes which were artificially inseminated (ai). in total 240 kurdi ewes, weighing 49.5±2.5 kg were used in the trail. the ewes were allocated randomly to one of four groups (n=60/in each group). for synchronizing, controlled internal drug release (cidr) was placed in the vagina of all individuals for 14 days. after ...

Icelandic ewes, living under natural photoperiod conditions, were treated with daily melatonin (2.5 and 10 mg day-1) for 75 days from the autumn equinox. Ewes were also exposed to a ram from the autumn equinox until the end of June, for 30 days from the end of the anoestrous period (30 October), and from 11 December for 30 days during the oestrous season. Blood samples were collected three time...