Fertility of fresh and frozen-thawed goat semen during the nonbreeding season.

A total of 4109 does of a local Greek breed (Capra prisca) were synchronized with intravaginal MPA-sponges and PMSG, and 24 bucks of Alpine (n = 8), Saanen (n = 8) and Damascus (n = 8) breeds were used for studying the fertility of nonfrozen and frozen-thawed semen during the nonbreeding season (June to August). Artificial insemination (AI) was performed once (50 to 55 h after sponge withdrawal) or twice (36 and 60 h after sponge withdrawals with fresh semen (collected during the nonbreeding season, stored at 16 degrees C and inseminated within 6 h) or frozen semen (prepared from the same bucks during the preceding breeding season). The induction of estrus was successful, varying between 91.

Enzyme activity in bovine cervical mucus during spontaneous and induced estrus.

The purpose of the present research was to compare the enzyme activity of alkaline phosphatase (ALP), lactate dehydrogenase (LDH), alpha-amylase, alpha-manosidase, beta-N-acetyloglucosaminidase, beta-glucuronidase, and beta-galactosidase in the cervical mucus of cows during spontaneous and induced estrus. Friesian cows (n = 106) were assigned to 4 groups: 1) no treatment; 2) progesterone releasing intervaginal device (PRID) for 12 days plus pregnant mare serum gonadotrophin (PMSG) at the removal of the PRID; 3) PGF2alpha 2 doses 11 days apart; and 4) PRID for 7 days plus PGF2alpha 1 dose, 24 hours before removal of the PRID. Fourteen cows were excluded from the trial because of an inadequate quantity of cervical mucus collected or a lost PRID.

Concentration of calcium, zinc, magnesium, potassium and sodium in the bovine cervical mucus during normal oestrus and oestrus induced by progesterone and/or PGF(2alpha).

Ninety-two healthy Friesian cows were used to determine the concentration of calcium (Ca), zinc (Zn), magnesium (Mg), potassium (K) and sodium (Na) in bovine cervical mucus and to compare these concentrations in cervical mucus collected during spontaneous and induced oestrus. Cows were assigned to four groups: (1) no treatment (2) PRID for 12 days plus pregnant mare's serum gonadotrophin (PMSG; 1000 IU, i.m.

Chemical properties of bovine cervical mucus during normal estrus and estrus induced by progesterone and/or PGF2alpha.

Ninety-two Friesian cows were used to determine the chemical properties of cervical mucus during normal estrus and estrus induced by progesterone (P4)-releasing intravaginal devices (PRID) and/or prostaglandin F2alpha. The animals were assigned to 4 groups (no treatment, a PRID for 12 days plus injection of 1000 IU PMSG at the removal of PRID, a double i.m.

Physical properties of bovine cervical mucus during normal and induced (progesterone and/or PGF2alpha) estrus.

Ninety two Friesian cows were used to determine physical properties of cervical mucus collected during normal estrus and estrus induced. Estrus was induced using either progesterone (P4) releasing intravaginal devices (PRID) and/or prostaglandin F2alpha (PGF2alpha). The animals were assigned to 4 groups (no treatment, a PRID for 12 days plus an injection of 1000 IU PMSG at the removal of the PRID, a double injection of 3 mL PGF2alpha 11 days apart, and a PRID for 7 days plus an injection of PGF2alpha 24 h before the removal of PRID).

Effects of cadmium chloride administration on the macroscopic and microscopic characteristics of ejaculates from Chios ram-lambs.

The effects of cadmium chloride on the volume of the ejaculate, semen density, total number of spermatozoa per ejaculate, viability, grade of motility, and morphological abnormalities were studied in 3-month-old ram-lambs of the Chios breed. Two groups of seven animals each were used. For a period of 7 months, one group was treated with a daily oral dose (3 mg/kg b.

Relationship between certain physical properties of cervical mucus and fertility in cows.

The object of the present investigation was to determine several physical properties of cervical mucus in spontaneous oestrus cows in relation to fertility. Because, it is very difficult to determine the exact time of the beginning of oestrus in cows, the aim of the present study was to investigate if physical properties of cervical mucus at the time of artificial insemination (AI) are related to conception or not. A total of 93 cows of Friesian breed were used.

The evaluation of the role of CCK in the opioid modulation of the motility of the gastrointestinal tract in sheep.

The participation of central cholecystokinin-8 (CCK-8) receptors in the modulatory effect of D-Ala2, N-Me-Phe4, Gly5-ol enkephalin (DAGO), a selective mu-opioid receptor agonist, on the spike burst activity of the gastrointestinal tract (rumen, reticulum, antrum, duodenum, colon and caecum) in sheep was investigated. DAGO was infused intracerebroventricularly (i.c.

Types of serotonergic receptors involved in the control of reticulo-ruminal myoelectric activity in sheep.

The effects of peripheral (intravenous, i.v.) and central (intracerebroventricular, ICV) administration of agonists of 5-HT1A, 5-HT2, 5-HT3 and 5-HT4 receptors were investigated in conscious sheep chronically fitted with intraparietal electrodes on the reticulum and the dorsal, ventral and caudo-ventral rumen.

Motor-modifying properties of 5-HT3 and 5-HT4 receptor agonists on ovine abomasum.

The effects and sites of action of 5-HT3 and 5-HT4 receptor agonists and antagonists on the abomasal myoelectric activity were examined in conscious sheep, chronically fitted with intravenous (i.v.) and intracerebroventricular (ICV) cannulas and intraparietal electrodes on the gastric body and antrum.

The role of GABA receptors in the control of the omasal myoelectrical activity in sheep.

Gamma-aminobutyric acid (GABA) receptor-mediated modification of omasal spiking activity (SA) was studied in six conscious ewes at rest, chronically fitted with electrodes implanted in the reticular and omasal walls and a cannula placed in the left cerebral lateral ventricle. Intracerebroventricular (0.1 microgram kg-1) but not intravenous (25 micrograms kg-1) administration of muscimol increased both the duration of omasal SA and the frequency of groups of spiking bursts (GSB) from the reticulum and oral omasum; the frequency of GSB from the aboral omasum decreased.

Central and peripheral serotonergic influences on viscerovisceral inhibitory reflex during duodenal distension in sheep.

The effects of duodenal distension on forestomach and abomasal motility were investigated in conscious sheep chronically fitted with intraparietal electrodes, a duodenal cannula, and an intracerebroventricular cannula. Duodenal distensions with a balloon inflated with 40 ml (DD40) of water reduced the frequency of forestomach and abomasal contractions by 45 and 32%, respectively, while distension with 80 ml (DD80) induced a total inhibition. Methysergide, a mixed 5HT1-5HT2 antagonist administered intravenously (200 micrograms/kg) or intracerebroventricularly (20 micrograms/kg) suppressed the DD40-induced inhibition and reduced that induced by DD80.

Myoelectrical responses of pyloric antrum to GABAergic agents in conscious sheep.

The role of GABA receptors in the control of abomasal motility was examined electromyographically in four conscious ewes by injecting intracerebroventricularly and intravenously selective GABA(A)- and GABA(B)-receptor agonists and antagonists. The study indicated that the stimulation of the GABA(B) receptors results in an inhibition of the antral motility via central mechanisms.

GABA receptor-mediated modification of reticulo-ruminal myoelectrical activity in sheep.

The involvement of central and peripheral GABA receptors in the control of the forestomach periodic motor activity was examined in five conscious ewes at rest, chronically fitted with electrodes implanted in the reticular and ruminal wall and a cannula placed in a cerebral lateral ventricle. Intravenous (IV) administration of the GABAA receptor agonist muscimol (5-50 micrograms/kg) did not affect reticulo-ruminal myoelectrical activity, while its intracerebroventricular (ICV) injection (0.05-0.

An electromyographic study of uterine activity during normal and progestogen-regulated estrus in the ewe.

Myometrial electrography was performed by means of chronically implanted electrodes in the base, the middle and the tubal end of both the uterine horns of six Serres ewes at normal and progestogen-regulated estrus. During the first 24 h of normal estrus, myometrial electrical activity was characterized by intermittent spike bursts (Pattern I activity), occurring at about the same frequency in the three sites of both horns (middle of the right horn: 44.13+/-6.

Central and peripheral alpha-adrenergic control of ileal, caecal and proximal colonic myoelectrical activity in sheep.

The role of central and peripheral alpha-adrenoceptors in regulation of ileal, caecal and proximal colonic myoelectrical activity was studied in five conscious ewes chronically fitted with intraparietal electrodes and a cannula in a lateral ventricle of the brain. About 5 min after the end of a regular spiking activity (RSA) phase of a migrating motor complex (MMC) in the distal ileum, selective alpha 2- and alpha 1-agonists and antagonists were administered intravenously (i.v.

Central and peripheral beta-adrenergic influences on reticulo-rumen and upper-gut myoelectrical activity in sheep.

The effects of intravenous (i.v.) and intracerebroventricular (i.

Involvement of alpha-adrenoreceptors in the regulation of omasal cyclic myoelectrical activity in sheep.

In five conscious adult ewes at rest, chronically implanted with electrodes in the musculature of the omasal wall, intravenous (i.v.) infusion for 30 min of alpha 1- or alpha 2-adrenergic receptor blockers, prazosin (20 micrograms/kg/min) and yohimbine (30 micrograms/kg/min), respectively, had no significant effects on omasal myoelectrical activity.

The adrenergic receptors in the control of reticulo-ruminal myoelectrical activity in sheep.

The involvement of adrenoreceptors in the control of reticulo-ruminal (R-R) motility was electromyographically studied in five conscious adult ewes. Intravenous (i.v.

Forestomach motility in adult sheep when reticular groove closure is provoked by copper sulphate solution.

Forestomach motility in adult sheep when reflex reticular groove closure is provoked by 10 ml of 10% copper sulphate solution was studied electromyographically. Rumen and omasum motility disappeared with the administration of the stimulant, while some muscular activity of the reticulum was always present but was manifested by monophasic, more frequent and weaker contractions than before stimulation; between these contractions very frequent small discharges appeared in the electromyogram from the reticulum. Cyclic activity of the forestomach reappeared 3 to 5 min later and returned gradually to normal.