Multiple injections of vitamin E and selenium improved the reproductive performance of estrus-synchronized Awassi ewes.

The aim of the current study was to investigate the effects of injecting estrus-synchronized ewes with vitamin E and selenium (Se) on their reproductive performance. Awassi ewes (n = 74) were randomly assigned into one of two groups. Group one (control, n = 36) did not receive vitamin E/Se injections, and group two (vitamin E/Se, n = 38) received 13.6-mg/kg BW of vitamin E plus 0.045-mg/kg BW of Se. Concurrent with estrus-synchronization program, vitamin E/Se injections were given at the time of insertion, withdrawal, and 19 days after withdrawal of intravaginal sponges. At all injection times, serum samples were collected (20 ewes per group) to measure Se contents. Pregnancy rates were evaluated by progesterone assay and by ultrasonography, respectively, at days 19 and 40 after sponge removal. Lambing rate, singles and twins%, sex ratio (M:F), and birth weight were recorded at lambing. Vitamin E/Se injections did not affect (P > 0.25) BW at lambing or BW change of ewes from breeding to lambing. Vitamin E/Se injections tended (P = 0.08) to decrease total pregnancy losses from 44.8 to 24.3%, subsequently, injections positively improved (P < 0.05) pregnancy rates determined by progesterone assay (from 80.6 to 97.4%) and ultrasonography (from 63.9 to 86.8%). Although overall fertility was not affected, vitamin E/Se injections markedly increased the percentage of ewes that lambed after only one service from 64.0 to 93.3%. Singles and twins%, lamb sex ratio, and birth weight of lambs were not affected (P > 0.20) by vitamin E/Se injections. Under conditions of our study, multiple injections of vitamin E/Se improved the reproductive performance of estrus-synchronized ewes.

Effect of thermal manipulation of broilers embryos on the response to heat-induced oxidative stress.

Effects of embryonic thermal manipulation (TM) on mRNA expressional levels and total antioxidant capacity of genes associated with heat-induced oxidative stress (NOX4, GpX2, SOD2, catalase, and AvUCP) in 2 breeds of broiler chicken were investigated. Fertile Cobb and Hubbard eggs (n = 1,200) were divided into 4 treatment groups: Cobb control, Cobb TM, Hubbard control, and Hubbard TM. Control groups were maintained under standard conditions (37.8°C; 56% relative humidity), whereas TM groups were incubated at 39°C and 65% relative humidity for 18 h a day from embryonic days (ED) 10 to 18. On post-hatch day 28, the broilers were subject to acute heat stress (AHS) at 40°C for 7 h. At certain intervals (0, 1, 3, 5, and 7 h), 12 chickens from each of the 4 groups were humanely euthanized, and liver samples were immediately isolated. During AHS, in both breeds, the mRNA expression levels of NOX4, GPx2, SOD2, and catalase in TM chickens were significantly lower than in controls, but AvUCP mRNA expression in the TM group was higher. The total antioxidant capacity and activity of superoxidase dismutase and catalase were significantly lower in the TM than in the control group in both breeds. The results of this study suggest that TM has a long-lasting effect on the acquisition of thermotolerance in 2 broiler chicken breeds as indicated by the reduction of system genes associated with heat-induced oxidative stress.

Lumpy Skin Disease in Jordan: Disease Emergence, Clinical Signs, Complications and Preliminary-associated Economic Losses.

The objectives of this study are to report the emergence of lumpy skin disease (LSD) in Jordan and associated clinical signs, complications and preliminary economic losses. In mid-April, 2013, two adult dairy cattle developed clinical signs suggestive of LSD and were confirmed as positive by PCR. The two cases were in Bani Kenanah district, Irbid governorate, on the Jordanian border of Israel and Syria. The disease spread rapidly to all the districts of Irbid governorate. During the month following the emergence of the disease, data were collected related to the epidemiology of the disease and the numbers of affected cattle on the premises. Forty-one dairy cattle holdings were surveyed. The morbidity rate ranged from 3% to 100%, (Mean = 35.1%, SD ±28.5%). The mortality rate ranged from 0% to 20%, (Mean = 1.3%, SD ±4.4%). The case fatality rate ranged from 0% to 100%, (Mean = 6.2%, SD ±22%). The overall morbidity rate was 26%, mortality rate 1.9% and case fatality rate 7.5%. Skin nodules, anorexia, decreased milk production and decreased body weight were common clinical signs, while mastitis and myiasis were seen as complications in a few affected animals. Decreased body weight ranged from 0% to 80%, (Mean = 23.1%, SD ±15.7%). Decreased milk production ranged from 0% to 100%, (Mean = 51.5%, SD ±22.2%). Affected cattle were treated mainly with broad-spectrum antibiotics and anti-inflammatory drugs. The cost of treatment ranged from 0 to 84.3 British Pound/animal, (Mean = 27.9 GBP, SD ±22.5 GBP). LSD continues to spread through the Middle East region and poses a serious threat to the rest of Asia and Europe. International collaboration and communication is warranted to prevent the further spread of the disease to the rest of Asia and Europe.

Molecular and histopathological characterization of sheep-associated malignant catarrhal fever (SA-MCF) outbreak in beef cattle.

An outbreak of suspected malignant catarrhal fever (MCF) was investigated by molecular and histopathological assays. Of the 70 Holstein beef calf herds, 14 were affected by multiple clinical signs suggestive of MCF infection. These beef calves were housed next to sheep flocks. In the complete blood count, the 14 affected calves had severe anaemia with leucopaenia, lymphopaenia and neutropaenia. Upon PCR amplification using a hemi-nested PCR assay for the detection of the Ovine herpesvirus 2 (OvHV-2), bovine tissue samples from the mesenteric lymph nodes and spleen and ovine blood samples were shown to be positive with the expected PCR bands amplified. Direct sequencing of the hemi-nested PCR product confirmed the identity of the causative virus as OvHV-2. The histopathological findings confirmed the clinical and laboratory diagnosis of MCF. Collective clinical, PCR and histopathological data confirmed the identity of this outbreak to be a sheep-associated malignant catarrhal fever (SA-MCF).

Endometrial phospholipase A2 activity during the oestrous cycle and early pregnancy in mares.

The aim of this study was to determine phospholipase A2 (PLA2) kinetics and activity in the mare's endometrium during the oestrous cycle and early pregnancy. Phospholipase A2 is responsible for the liberation of arachidonic acid from phospholipids, which is the first limiting step in prostaglandins synthesis. Phospholipase A2 activity was measured using an assay based on the liberation of oleic acid from 1-palmitoyl-2-[(14) C] oleoyl phosphatidylcholine. The enzyme was shown to be calcium dependent, to have an optimum pH of 8 and an apparent Michaelis constant of 127 µM. Enzyme activity was low in the endometrium of early luteal phase tissue but increased significantly (p < 0.001) during the late luteal phase (5.39 ± 0.16; 3.48 ± 0.33, 6.85 ± 0.59, and 9.96 ± 1.23 nmol oleic acid released/mg protein at oestrus, and Days 3, 8 and 14 after ovulation, respectively). The mean PLA2 activity in endometrial tissue from pregnant mares (4.23 ± 0.74) was significantly lower (p < 0.01) than from cyclic animals during late dioestrus (9.96 ± 1.23). The results indicate that PLA2 activity in equine endometrium changes with the stage of the oestrous cycle and thus may be influenced by systemic hormone concentrations. The inhibitory effects of conceptus products on secretion of prostaglandin during early pregnancy were associated with a competitive inhibitor that decreased endometrial PLA2 activity.

Effect of acute bull exposure around the time of artificial insemination on serum oxytocin and progesterone concentrations and pregnancy rates in dairy cows.

This study examined the effect of acute bull exposure around the time of artificial insemination (AI) on oxytocin and progesterone concentrations, and pregnancy rates in dairy cows. Ninety six dairy cows, stratified according to parity into primiparous and pluriparous, were divided into three groups; short bull exposure (SBE; 10 min, n = 32), long bull exposure (LBE; 4 h, n = 32) or no bull exposure (NBE; n = 32). On day 45 post-partum, all cows were treated with PGF2α on three occasions 11-14 days apart to synchronize oestrus. They were submitted to fixed time AI 80 h after the third PGF2α injection. Cows in the SBE and LBE groups were artificially inseminated 5 min after the introduction of the bull. From a subset of cows (n = 6 per group; three primiparous and three pluriparous), blood samples were collected once every 5 min starting 15 min before AI until 15 min after AI and analysed for oxytocin concentrations. Additional blood samples were collected for measurements of progesterone (P4) concentrations once daily for 4 days starting on the day of AI and once every 3 days thereafter until day 22. The effects of bull exposure, time, parity, difficulty of AI, and pregnancy on oxytocin and P4 concentrations were analysed using the mixed linear model procedure. Mean oxytocin concentrations or change in oxytocin concentrations after bull exposure or AI were not different among groups. Pregnancy rates for the NBE, SBE and LBE groups were 55.5%, 33.3% and 44.4%, respectively, and were not different among groups. In conclusion, acute bull exposure around the time of AI did not affect oxytocin and progesterone concentrations and did not improve pregnancy rates in dairy cattle under these farms conditions.

Ovarian steroid regulation of endometrial phospholipase A2 isoforms in horses.

Real-time PCR was used to investigate the role of progesterone (P4) and oestradiol (E2) in regulation of endometrial cytosolic, secretory and calcium-independent phospholipase A2 (PLA2G4A, PLA2G2A and PLA2G6, respectively) gene expression. Ovariectomized mares underwent 6 days of E2 pre-treatment followed by 14 days of P4 supplementation. At the start of P4 treatment (Day 1), mares were assigned in a 2 × 2 factorial design to receive either E2 or vehicle starting on Day 11 and endometrial biopsy collection on either Day 14 when P4 concentrations remained high (>4 ng/ml) or Day 16 when P4 concentrations had declined (0.5-2 ng/ml). Additional biopsies were collected from ovariectomized mares on Day 8, which served as control. Blood samples were collected for P4 determination. PLA2G4A expression was higher (p < 0.05) on Day 14 compared with Day 8. In contrast, PLA2G2A did not change significantly (p < 0.12). PLA2G4A and PLA2G2A gene expression increased (p < 0.05), as P4 concentration dropped, on Day 16. In contrast, PLA2G6 gene expression did not show differences between days. Treatment with oestradiol did not increase PLA2 isoforms expression when compared to treatment with the vehicle. PLA2G4A and PLA2G2A were positively correlated with each other and negatively correlated with P4 concentrations. In conclusion, P4 withdrawal upregulated PLA2G4A and PLA2G2A gene expression, and this was not affected by E2. PLA2G4A and PLA2G2A but not PLA2G6 gene expression may be involved in controlling prostaglandin F2 alpha synthesis and luteolysis.

Pathological, immunological and molecular diagnosis of rabies in clinically suspected animals of different species using four detection techniques in Jordan.

A total of 29 brain tissue samples (BTS) were examined for rabies infection by different diagnostic techniques. None of the examined brain tissues were presented as a whole intact brain. Twenty-seven brain tissue samples from various animal species - dog (13 cases), cat (one case), fox (one case), pig (one case), cow (three cases), sheep (two cases), goat (one case), camel (one case), horse (one case) and donkey (three cases) - were provided by the Vaccine and Sera Department/Al-Bashir Central Hospital in Amman/Jordan from July 2009 up to May 2010. All these samples were frozen at -20°C, for a period of time and then fixed in 10% formalin after being tested for rabies virus by fluorescence antibody test (FAT). The results showed that 21 (77.77%) of 27 BTS were positive for rabies by FAT. Seventeen samples (58.62%) of 29 were positive by histopathology, 2 (6.90%) were positive by histopathology, immunohistochemistry (IHC) and of those which were fixed for 24h only, and 21 (72.42%) were positive using RT-PCR assay. Five of 29 BTS had no pathological lesions, 17 had Negri bodies and the remaining had non-suppurative encephalitis and necrosis. Thirteen BTS that were diagnosed positive by FAT were also positive by RT-PCR and histopathology, but negative by IHC. Four BTS that were positive by FAT were negative by histopathology, IHC and RT-PCR. Also, 3 BTS (cases 19, 22, and 25) that were negative by FAT were positive by RT-PCR and negative by IHC. One of these was negative, while two were positive by histopathology. Therefore, definitive diagnosis of rabies under these conditions in Jordan needs one or more other diagnostic tests in addition to FAT. Also, freezing and prolonged formalin fixation of BTS is not suitable for the detection of rabies virus antigen using IHC.

Applying variations of the Ovsynch protocol at the middle of the estrus cycle on reproductive performance of lactating dairy cows during summer and winter.

Two modifications of the Ovsynch protocol, GnRH+TAI after PGF(2 alpha) 48 h (CO-48) or 72 h (CO-72), were compared with the original protocol (OVS: GnRH-7 d-PGF(2 alpha)-2 d-GnRH-16 h-TAI) to study their effects on reproductive performance in 785 lactating dairy cows (Holstein Friesian, Bos Taurus). Results showed that more cows (P<0.001) returned to estrus within a week after TAI with CO-48 treatment compared with that in OVS and CO-72 treatments. Pregnancy rates were greater (P<0.001) for the CO-72 cows than those for both OVS and CO-48 treatments and for primiparous cows compared with multiparous cows. Moreover, pregnancy rates were lower in summer compared with those in winter. Pregnancy losses for cows in both CO-48 and CO-72 were greater (P<0.05) than that for cows in OVS treatment. Pregnancy losses were greater in summer (P<0.001) than in winter and for multiparous cows (P<0.001) than for primiparous cows. In conclusion, primiparous and winter-bred cows had greater pregnancy rates and fewer pregnancy losses than those of multiparous cows and summer-bred cows, respectively. Because of the presence of significant treatment, parity, and season interactions, TAI with ovulation synchronization protocols should be tailored according to the season and parity. CO-72 is recommended for primiparous cows but not for multiparous cows, and CO-48 is not recommended for synchronization. Furthermore, cows that exhibited estrus at any time were inseminated to improve pregnancy rates in ovulation synchronization protocols.

The effect of estrus synchronization treatments on somatic cell count of transitional-anestrus Awassi ewes' milk.

Fifty-three transitional-anestrus Awassi ewes, randomly assigned to three groups: fluorogestone acetate (FGA, n = 18), FGA-Prostaglandin (FGA-PGF, n = 18) and control (n = 17), were used to examine the effect of estrus synchronization protocols and steroid hormones concentrations on milk somatic cell count (SCC). Intravaginal FGA sponge was inserted for 13 days and 600 IU equine chorionic gonadotropin was administered for ewes of FGA and FGA-PGF groups at the time of sponge removal (day 0). In addition, 10 mg was administered to ewes of FGA-PGF group on day 0. Blood and milk samples were collected from all ewes on days -13, -6, 0, 1, 2, 7 and 14. Estradiol had significant positive correlation with the SCC during the periods of sponge insertion (P = 0.015, r = 0.235) and within two days (P = 0.063 r = 0.23) after sponge removal with no correlation with SCC of both udder halves during the luteal phase. Progesterone concentrations, on the other hand, had a significant positive correlation (P < 0.001; r = 0.420) with the SCC of both udder halves during the luteal phase of the experiment, but not during the periods of sponge insertion and expected estrus. SCC returned under the influence of endogenous progesterone on days 7 and 14 to pre-synchronization values. In conclusion, sheep milk SCC is affected significantly with induction of estrus and steroid hormones concentrations. However, peak SCC recorded during estrus was far below the upper limit of the current standard for normal milk. With the current standards for SCC of 1,000,000/ml as legal limit for abnormal milk control programs in sheep, estrus synchronization programs and the estrus status should not be considered when bulk-tank milk SCC is being investigated, but should be considered during the process of setting new standards.

Prevalence and risk factors associated with bovine viral diarrhea virus infection in dairy herds in Jordan.

A cross-sectional study was carried out to determine the seroprevalence and to identify risk factors associated with bovine viral diarrhea virus (BVDV) infection in 62 non-vaccinated dairy herds (671 cows) in Jordan between January and June 2007. Information regarding herd management was recorded through a personal interview with farmers. Antibodies against BVDV were detected using an indirect ELISA test. Chi-square analysis and multivariable logistic regression model were used to identify risk factors for BVDV seropositivity. The true prevalence of antibodies against BVDV in individual cows and cattle herds was 31.6% and 80.7%, respectively. The seroprevalence of BVDV in medium and large size herds was significantly higher than that in smaller herds. There was no significant difference in BVD seroprevalence between different age groups. Random-effects logistic regression model revealed two major factors associated with seropositivity to BVDV; exchange of visits between adjacent farm workers and not isolating newly purchased animals before addition to the herd. The seroprevalence of BVDV in cows located in the northern Jordanian governorates was significantly higher than that in other studied governorates. Results of this study indicated that BVDV is highly prevalent in Jordan and BVDV infection could be controlled by livestock-trade control, and applying strict biosecurity measures in the dairy farms.

The effect of estrus synchronization treatment on somatic cell count of transitional-anestrus local-Damascus cross breed goats' milk.

An experiment was conducted to examine the effect of estrus synchronization protocols and steroid hormones concentrations on somatic cell count (SCC) of transitional-anestrus local-Damascus cross goats' milk. Fifty-six goats (2-4-year old) were randomly assigned to three groups: fluorogestone acetate (FGA, n = 19), FGA-Prostaglandin (FGA-PGF, n = 19) and control (n = 18) groups. Intravaginal sponge containing 40 mg FGA was inserted for 13 days and an injection of 600 IU equine chorionic gonadotropin (eCG) was administered for goats of FGA and FGA-PGF groups at the time of sponge removal (day 0). In addition, goats of FGA-PGF group were injected with 10 mg dinoprost tromethamine (PGF2alpha) on day 0. Five fertile local-Damascus cross bucks were turned-in with all goats on day 0. Blood and milk samples were collected from all goats on days -13 (beginning of experiment), -6, 0, 1, 2, 7, 13 and 20 (end of the experiment). Four-year old and second-parity goats had significantly higher (p < 0.05) SCC of both udder halves than 2- and 3-year old and first-parity goats, respectively. There was a significant effect (p < 0.05) for treatment and number of kids born in the last kidding season on SCC of both udder halves. Neither estradiol nor progesterone concentrations were correlated with SCC in goats in this experiment. The SCC of both udder halves and left udder halves in goats of the control and FGA groups, respectively, increased significantly (p < 0.05) after sponge removal and buck introduction when compared with day 0, with no differences in the FGA-PGF group. This increase in SCC of the control and FGA groups coincided with peak estrus behavior. However, SCC was far below the upper limit of the current standard for normal milk. In conclusion, induction of estrus with progestagen based programs and buck introduction may cause temporary significant increase in SCC. However, the SCC values during this period of temporary increase were still in the range of acceptable values for normal milk. With the current standards for SCC of 1,000,000/ml as legal limit for abnormal milk control programs in goats, estrus synchronization programs and the estrus status should not be considered when bulk-tank milk SCC is being investigated.

A new strategy for superior reproductive performance of ewes bred out-of-season utilizing progestagen supplement prior to withdrawal of intravaginal pessaries.

Two experiments were conducted to examine the effect of progestagen supplement 24h prior to intravaginal pessary withdrawal on reproductive performance of seasonal anestrous ewes. Ewes in each experiment were allocated to treatment and control and all were induced to estrus using either intravaginal MAP (Exp. 1; n=24) or CIDR-G (Exp. 2; n=28) pessaries for 12 days. Half of the ewes in each experiment were supplemented 24h before withdrawal of pessaries with either 10mg oral MAP tablets (Exp. 1) or 25mg i.m. progesterone (P(4)) administration (Exp. 2; P(4)-supplement-treated group). Fertile rams were allowed with the ewes at sponge removal (Day 0, 0h) and estrus was monitored at 6-h intervals for 3 days. Blood samples were collected for measurements of P(4) (Exp. 1 and Exp. 2) and LH (Exp. 2). In both experiments, the percent of ewes in estrus was greater (P<0.05) and intervals to estrus were longer (P<0.05) in progestagen-supplement-treated than control ewes. In Exp. 2, the occurrence and magnitude of LH surges were greater (P<0.01) and intervals to onset of LH surge were longer (P<0.01) in P(4)-supplement-treated than control ewes. In Exp. 2, P(4) supplement elevated P(4) levels from 1.8+/-0.1ng/mL on Day -1 to 4.2+/-0.3 on Day 0 (P<0.001). Following pessaries removal, P(4) concentrations fell to basal values on Day 1 in both groups and remained low until Day 5. Then, P(4) concentrations increased and remained elevated through Day 19 in all (100%) progestagen-supplement-treated in Exp. 1 (12/12) and Exp. 2 (14/14) and in only 5/12 (41.7%) and 6/14 (42.9%) control ewes, respectively. These ewes were confirmed pregnant by ultrasonography and lambed on Day 149.2+/-0.2 following Day 0. In conclusion, progestagen supplement 24h prior to removal of pessary can be used successfully to improve reproductive performance of ewes bred out-of-season.

Bacteriological findings and hormonal profiles in the postpartum Balady goats.

Twenty-six Balady goats categorized according to parity into primiparous and pluriparous goats were used to investigate bacterial flora of the genital tract and hormonal profiles during the postpartum (PP) period. Escherichia coli and Staphylococcus aureus were isolated in pure or mixed culture from the uterus. Arcanobacterium pyogenes was isolated from swabs obtained from the vagina and cervix of one primiparous goat. Uteri and cervices but not vaginas were free of bacterial contamination by day 10 PP except for one pluriparous goat with scanty E. coli contamination on day 25 PP. Fluctuating oestradiol 17beta (E2) levels demonstrated resumption of follicular activity as early as day 13 PP in both parity groups. Progesterone (P4) levels remained low at basal levels throughout the study period. Higher concentrations of 15-keto-13,14-dihydroprostaglandin F2alpha (PGFM) were observed during the first week PP compared with the rest of the PP period. PGFM concentrations dropped to low basal level by day 10 PP and remained constantly low throughout the study period. P4, E2 and PGFM profiles were not different between the different parity groups. In conclusion, intrauterine infection is not common in goats with normal kidding. E. coli was the most common intrauterine bacterial isolate. E2 and P4 profiles were consistent with resumption of follicular growth but not ovulation. High PGFM concentrations coincided with the fast regression phase of uterine involution. Hormonal profile and bacterial contamination and clearance were similar to those reported in other related species and not related to parity.

Ultrasonic assessment of puerperal uterine involution in Balady goats.

Twenty-six postpartum Balady goats (primiparous, n=13; pluriparous, n=13) were used in this study. One animal of each group was slaughtered on postpartum days 1, 2, 4, 7, 10, 13, 19 and 25; in addition, three control nulliparous goats were slaughtered, and the genital tracts collected. Progress of uterine involution was monitored by repeated ultrasonographic measurements in live animals (primiparous n=6; pluriparous n=6) and measurement of the outer circumference of the uterine horns of slaughtered animals (primiparous n=8; pluriparous n=8). A consistent and progressive decrease in ultrasonographic and outer circumference measurements was found, although faster during the first 7 days postpartum than between days 7 and 19 postpartum. Uterine involution, assessed by the upper limit of the measurements in the nulliparous goats, followed a quadratic pattern and was completed by day 19 postpartum. Ultrasonographically, two elliptical-circular echogenic areas separated by an anechoic line of the stratum vascularis were depicted. Regressing caruncles and fluid in uterine lumen were recognized during the first week postpartum. Further analysis revealed a highly positive correlation between the outer circumference and ultrasonographic measurements. In conclusion, uterine involution in Balady goats was completed by day 19 postpartum and was unrelated to parity. The close association between ultrasound findings and macroscopic involution indicated that ultrasonography can dependably be used to monitor uterine involution under field conditions and can be a suitable alternative to animal slaughter for the study of uterine involution.

Effect of periovulatory prostaglandin F2alpha on pregnancy rates and luteal function in the mare.

The objective of this study was to determine whether periovulatory treatments with PGF2alpha affects the development of the CL, and whether the treatment was detrimental to the establishment of pregnancy. Reproductively sound mares were assigned randomly to one of the following treatment groups during consecutive estrus cycles: 1. 3,000 IU hCG within 24 hours before artificial insemination and 500 microg cloprostenol (PGF2alpha analogue) on Days 0, 1, and 2 after ovulation (n=8), 2. 2 mL sterile water injection within 24 hours before artificial insemination and 500 microg cloprostenol on Days 0, 1, and 2 after ovulation (n=8); 3. 3,000 IU hCG within 24 hours before artificial insemination and 500 microg cloprostenol on Day 2 after ovulation (n=8); or 4. 3,000 IU hCG within 24 hours before artificial insemination and 2 mL of sterile water on Days 0, 1, and 2 after ovulation (controls; n=8). Blood samples were collected from the jugular vein on Days 0, 1, 2, 5, 8, 11, and 14 after ovulation. Plasma progesterone concentrations were determined by the use of a solid phase 125I radioimmunoassay. All mares were examined for pregnancy by the use of transrectal ultrasonography at 14 days after ovulation. Mares in Group 1 and 2 had lower plasma progesterone concentrations at Day 2 and 5, compared to mares in the control group (P < 0.001). No difference was detected between group 1 and 2. Plasma progesterone concentrations in group 3 were similar to the control group until the day of treatment, but decreased after treatment and were significantly lower than the control group at Day 5 (P < 0.001). Plasma progesterone concentrations increased in all treatment groups after Day 5, and were comparable among all groups at Day 14 after ovulation. Cloprostenol treatment had a significant effect on pregnancy rates (P < 0.01). The pregnancy rate was 12.5% in Group 1, 25% in Group 2, 38% in Group 3, and 62.5% in Group 4. It was concluded that periovulatory treatment with PGF2alpha has a detrimental effect on early luteal function and pregnancy.

Inhibin localization in equine granulosa-theca cell tumours and inhibin forms in tumour fluid.

The aim of this study was to examine inhibin production in granulosa-theca cell tumours (GTCT). The experimental aims were: (i) to determine GTCT cell types that produce inhibin alpha- and betaA-subunits; (ii) to determine whether alpha- and betaA-subunit forms differ in GTCT fluid and normal equine follicular fluid (eFF); and (iii) to determine whether dimeric inhibin (alpha betaA) is present in GTCT plasma and tumour fluid. Plasma, tumour fluid and tumour tissue were collected from mares (n=6) with GTCT. Plasma and eFF were collected during the follicular phase from mares (n=4) undergoing normal cycles. Immunohistochemical examination of GTCT tumour sections showed strong inhibin alpha- and betaA-Subunit immunostaining in granulosa cells and polyhedral-shaped cells in the thecal-stromal layer. The presence of polyhedral-shaped cells was related to testosterone concentration in tumour fluid. Low molecular weight alpha-subunit forms were less abundant in tumour fluid than in eFF, whereas the amounts of betaA-subunit forms were similar in tumour fluid and eFF. Concentrations of betaA were increased in plasma from mares with GTCT and similar in tumour fluid and eFF. In summary, lower molecular weight alpha-subunit forms were less prominent in GTCT fluid than in eFF and concentrations of betaA were higher in GTCT plasma than in control plasma.

Partial characterization of an equine conceptus prostaglandin inhibitory factor.

Equine conceptuses are thought to produce antiluteolytic factors that inhibit endometrial PGF2alpha and, thus, prevent luteolysis in pregnant mares. The aim of the present study was to characterize partially the chemical nature of the prostaglandin inhibitory factor (PIF) produced by equine conceptuses in vitro. Embryos were collected from pregnant mares 13 +/- 0.5 days after ovulation and were cultured for 24 h. Harvested equine conceptus conditioned media (CCM) were assayed for antiluteolytic activity by determining the inhibition of endometrial PGF2alpha synthesis in vitro. Significant antiluteolytic activity was found in the CCM at 12, 18 and 24 h. After size fractionation, antiluteolytic activity was observed in the 3-10 kDa fraction and the activity was not destroyed by proteinase K digestion. In contrast, treatment with dextran-coated charcoal removed the antiluteolytic activity from the CCM at 12, 18 and 24 h of culture (P < 0.05). These results indicate that the prostaglandin inhibitory factor is a low molecular mass (3-10 kDa) proteinase K-resistant substance that may be adsorbed by dextran-coated charcoal. The chemical nature, antiluteolytic activity and time of synthesis of the PIF by early equine conceptuses indicate that the PIF identified in the present study may be involved in the maternal recognition of pregnancy factors in mares.

Dimeric inhibin concentrations in mares with granulosa-theca cell tumors.

OBJECTIVE: To determine whether concentrations of dimeric inhibin (CaCA) are greater in plasma and tumor fluid from mares with granulosa-theca cell tumors (GTCT), compared with concentrations in plasma and equine follicular fluid (eFF) from control mares. ANIMALS: 6 mares with GTCT and 12 clinically normal mares. PROCEDURE: The alphabetaA immunoradiometric assay used 2 antibodies, one against each subunit of inhibin (alpha and betaA subunits). Tumor tissue, tumor fluid, and a single blood sample were collected at the time of surgical removal of the GTCT. A single blood sample was collected from 7 control mares during various stages of the estrous cycle. Five other control mares were ovariectomized when their ovaries contained growing follicles of 25 to 35 mm in diameter. A blood sample and eFF from the largest follicle were collected at the time of ovariectomy. RESULTS: Mares with GTCT had significantly greater plasma concentrations of betabetaA (mean +/- SEM, 0.86 +/- 0.53 ng of recombinant human-alphabetaA/ml), compared with control mares (0.14+/-0.02 ng/ml). Concentrations of alphabetaA in tumor fluid and eFF were similar. Concentrations of alphabetaA were significantly lower after ovariectomy. CONCLUSIONS AND CLINICAL RELEVANCE: Dimeric inhibin concentration was higher in plasma from mares with GTCT than in plasma from control mares. Increased granulosa cell mass and loss of mechanisms regulating alphabetaA release in mares with GTCT likely accounted for the increase in plasma concentrations. Measurement of alphabetaA concentrations may be useful for identifying mares with GTCT.

Effect of eCG on the pregnancy rate of ewes transcervically inseminated with frozen-thawed semen outside the breeding season.

An experiment was conducted to determine whether factors affecting pregnancy rate out-of-season are associated more with transcervical artificial insemination (T-AI) procedures or with the reproductive state of the ewe. Twenty Finncross ewes were treated with progesterone sponges, and at sponge removal (0 h) 10 ewes were treated with eCG. Blood samples were collected for LH and progesterone analyses, and follicular development was monitored using ultrasonography. Ewes were inseminated from 48 to 52 h with 200 million motile frozen-thawed spermatozoa. The incidence of estrus, LH surges and ovulation was greater (P < 0.01) and intervals to these responses were shorter (P < 0.01) in the eCG-treated ewes. The number of follicles > 5 mm was higher (P < 0.05) in eCG-treated than control ewes. Progesterone concentrations increased and remained elevated through Day 19 in 7 eCG-treated and in 1 control ewe, and these ewes were pregnant based upon ultrasonographic examination. The results demonstrate that the T-AI technique using frozen-thawed semen produces a relatively high (70%) pregnancy rate out-of-season. The pregnancy rate was found to reflect primarily the reproductive condition of the ewe.