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11.
Paraoxonase‐1 (PON1) is an enzyme found in serum and follicular fluid that protects cell membrane and circulating lipids against oxidative damage. The aims of this study were to measure the direct effects of recombinant PON1 (rPON1) on bovine oocyte maturation at the molecular level (gene expression) and to measure the carry‐over effects of PON1 on pre‐implantation embryo development in vitro. COCs were submitted to IVM with the addition of 0.0, 0.02, 0.04 and 0.08 mg ml?1 of rPON1, corresponding to an average PON1 arylesterase enzyme activity of 2.2 ± 0.4, 15.5 ± 1.5, 30.2 ± 3.0 and 57.9 ± 5.0 U ml?1, respectively. The results indicated that addition of rPON1 during IVM improved embryo development in a dose‐dependent manner as D7 embryo development was 22.2%, 29.4%, 32.2% and 37.0% for the treatment groups, respectively (p = 0.02). In conclusion, addition of PON1 enzyme during IVM exerted dose‐related positive effects on embryo development rates to blastocysts.  相似文献   
12.
This study was designed to establish the factors, if any, which could affect plasma pregnancy-associated glycoprotein-1 (PAG-1) expression in a study population of 87 pregnant, high-producing dairy cows. The factors examined were: semen providing breed (Holstein-Friesian vs Limousin), outcome of gestation (male vs female newborn, and singleton vs twin pregnancies), lactation number, milk production at pregnancy diagnosis, plasma progesterone concentration, season of gestation (warm period, March–November vs cool period, December–February), and day of gestation (40, 90, 120, 150, 180 and 210). Pregnancy was diagnosed by transrectal ultrasound on day 40 post-insemination and by palpation per rectum on days 90, 120, 150, 180 and 210. Blood samples were collected from each animal immediately before each pregnancy diagnosis. The relative contributions of the different factors on PAG-1 concentrations were evaluated by GLM repeated measures analysis of variance. No significant effects of the herd, foetal sex, milk production, lactation number and plasma progesterone concentrations were observed. In contrast, twin pregnancy, the use of Limousin semen and conception during the cool period were correlated with significantly increased plasma PAG-1 concentrations throughout gestation. Our data indicate that both cow well-being during early placental development, determined in our conditions by reduced heat stress when conception occurred in the cool season, and crossbreed pregnancies lead to improved PAG-1 production throughout the gestation period.  相似文献   
13.
The demography of bovine infections caused by Mycobacterium avium subspecies paratuberculosis (MAP) in Ireland is poorly defined. The objective of this study was to describe the demographics of cattle positive to MAP on faecal culture, based on submissions to the Cork Regional Veterinary Laboratory (Cork RVL) from 1994 to 2006. The study focused on all available faecal samples from adult cattle with non-responsive chronic diarrhoea that were submitted by private veterinary practitioners to Cork RVL for MAP culture. For each MAP-positive by faecal culture animal, data were collated from Cork RVL and Cattle Movement Monitoring Scheme (CMMS) records. Johne's disease (JD) was confirmed in 110 animals from 86 herds by the Cork RVL between 1994 and 2006, with a rate of positive cases between 15% and 18% over last four years of the study. Two breeds (Holstein/Friesian or Limousin) made up 78% of submissions. Movements were assessed for the 57 study animals with available movement information, 90% died within one year of the test and 26% tested positive in the herd they were born into. The study provides preliminary information about movement trends and demographics of animals with MAP positive submissions. Although the study area is restricted, it includes the most intensive (and economically-important) dairy region in Ireland. The demographics of JD infection from the study area are in agreement with international reports. Further work is required to determine demographic trends, incidence and prevalence of JD throughout Ireland. It is hoped this work may contribute to the development of a surveillance strategy for MAP by regional veterinary laboratories.  相似文献   
14.
The sperm of European eel shows a high density and the time of spermatozoa motility is very short after activation with sea water. These characteristics make difficult the sperm handling and its quality assessment. Several diluents were previously described for the Japanese eel obtaining over 3 weeks’ conservation times under refrigeration, but they rendered bad results in the European species. In the present study, several diluents were developed taking as basis the P1 medium, and using different dilution ratios (1 : 50, 1 : 100) and two pH (6.5, 8.5). The effect of the addition of bovine serum albumin (BSA, 2% w/v) was also evaluated. At 24 h, undiluted samples already showed significant lower motility and viability than sperm samples diluted in the different media. The results for diluents with pH 6.5 and 8.5 were different. Spermatozoa diluted in media at pH 6.5 cannot be activated at 24 h, while samples diluted in the diluents with pH 8.5 and added with BSA did not show significant differences with respect to the fresh sperm motility until 48 h. The viability (percentage of alive cells) did not show differences until 1 week, independent of the dilution ratio. After 1 week, the motility was approximately 30% in the media containing BSA, which presented no differences for head size of the spermatozoa (perimeter and area) until 72 h and 1 week, respectively. In conclusion, the combination of one medium having similar physico‐chemical characteristics to the seminal plasma, including pH 8.5, and supplemented with BSA can be used in different dilution ratios for the sperm’s short‐term storage, preserving its motility capacity.  相似文献   
15.
Thirteen female Bedouin goats living in arid land of Algeria Sahara desert were used in this study. These goats were pregnant but they sustained an abortion because of unidentified causes. None of the goats showed any signs of general disease. Plasma concentrations of caprine pregnancy‐associated glycoproteins (cPAGs) and progesterone (P4) were determined during pregnancy using radioimmunoassay. The cPAGs concentration was undetectable (<0.8 ng/ml) throughout the first 2 weeks of gestation. From week 3 after mating, cPAGs concentration was detectable with significant individual variations (p < 0.05) reaching a maximum secretion (436.1 ng/ml). Throughout gestation, cPAGs concentration remained relatively constant but decreased few days before abortion, on an average of 9.2 ± 1.2 days (n = 11), except for two females where the concentrations decreased later (1–2 days before abortion). One or two peaks of cPAGs concentrations (in 4/13 and in 9/13 females, respectively) have been measured few weeks before abortion (77–124 days after mating), when a decline of cPAGs was detected. The P4 concentration increased after mating, and was high from the first week till the end of pregnancy. The P4 concentration (9.1 ± 0.9 ng/ml) decreased rapidly (<0.5 ng/ml) after 4 ± 0.7 days (n = 6) or 9.4 ± 1.6 days (n = 7) before abortion. A positive relationship (p < 0.01) was found between P4 and cPAGs concentrations during gestation. Results indicate that cPAGs and P4 measurements can be used for monitoring gestation and for abortion prediction.  相似文献   
16.
The insulin‐like growth factor‐I (IGF‐I) is a key regulator of reproductive functions. IGF‐I actions are primarily mediated by IGF‐IR. The main objective of this research was to evaluate the presence of IGF‐I and IGF‐I Receptor (IGF‐IR) in stallion testicular tissue. The hypotheses of this study were (i) IGF‐I and IGF‐IR are present in stallion testicular cells including Leydig, Sertoli, and developing germ cells, and (ii) the immunolabelling of IGF‐I and IGF‐IR varies with age. Testicular tissues from groups of 4 stallions in different developmental ages were used. Rabbit anti‐human polyclonal antibodies against IGF‐I and IGF‐IR were used as primary antibodies for immunohistochemistry and Western blot. At the pre‐pubertal and pubertal stages, IGF‐I immunolabelling was present in spermatogonia and Leydig cells. At post‐pubertal, adult and aged stages, immunolabelling of IGF‐I was observed in spermatogenic cells (spermatogonia, spermatocyte, spermatid, and spermatozoa) and Leydig cells. Immunolabelling of IGF‐IR was observed in spermatogonia and Leydig cells at the pre‐pubertal stage. The immunolabelling becomes stronger as the age of animals advance through the post‐pubertal stage. Strong immunolabelling of IGF‐IR was observed in spermatogonia and Leydig cells at post‐puberty, adult and aged stallions; and faint labelling was seen in spermatocytes at these ages. Immunolabelling of IGF‐I and IGF‐IR was not observed in Sertoli cells. In conclusion, IGF‐I is localized in equine spermatogenic and Leydig cells, and IGF‐IR is present in spermatogonia, spermatocytes and Leydig cells, suggesting that the IGF‐I may be involved in equine spermatogenesis and Leydig cell function as a paracrine/autocrine factor.  相似文献   
17.
ABSTRACT

Aims: To determine whether sheep that co-grazed with cattle that were suspected to be positive for bovine viral diarrhoea (BVD) virus had serological evidence of exposure to the virus.

Methods: Eighteen commercial farms that routinely co-grazed cattle and sheep in the same paddocks were recruited through purposive sampling. The recruiting veterinarians identified nine farms with cattle herds that were known or highly suspected to be positive for BVD and nine farms that were considered to be free of BVD. Blood samples were taken from 15 ewes aged 1 year on each farm and samples were submitted to a commercial diagnostic laboratory to test for antibodies against pestiviruses using an ELISA. All samples that were positive were then tested using a virus neutralisation test (VNT)for antibodies against BVD virus.

Results: Of the 270 blood samples, 17 were positive for pestivirus antibodies by ELISA and these originated from two farms that were known or suspected to have BVD virus-positive cattle. None of the samples from the nine flocks co-grazed with cattle herds that were known or suspected to be BVD virus-negative were positive for pestivirus antibodies. Within the two positive farms, 2/15 samples from the first farm and 15/15 samples from the second farm were antibody-positive. When the 17 positive blood samples were submitted for VNT, all 15 samples from the second farm tested positive for BVD virus antibodies with the highest titre being 1:512.

Conclusions and clinical relevance: In this small sample of New Zealand sheep and beef farms with suspected BVD infection in cattle, there was evidence of pestivirus exposure in co-grazed sheep. Although we were unable to confirm the origin of the exposure in these sheep, these findings highlight that farmers who are trying to eradicate BVD from their cattle should be mindful that the infection may also be circulating in sheep, and both populations should be considered a possible risk to each other for generating transient and persistent infections. Further work is needed to estimate the true prevalence of New Zealand sheep flocks that are affected by BVD and the associated economic impacts.  相似文献   
18.
19.
The lectin histochemical pattern (LHP) was characterized and compared in normal and cystic ovaries of sows. Six biotinylated lectins (PNA, SBA, WGA, RCA‐1, DBA and UEA‐1) were used on tissue sections. In the normal ovaries, the reaction to UEA‐1 and SBA was mild to moderate in mesothelial and endothelial cells. RCA‐1 staining was mild to moderate in theca interna of growing follicles, corpora luteum and mesothelium. In addition, this lectin presented strong reaction in endothelial cells, granulosa cells of atretic follicles, zona pellucida of growing follicles and plasma. DBA showed strong intensity in mesothelial and endothelial cells. There was mild to moderate reactivity to WGA in granulosa cells, corpus luteum and theca interna of follicles in development, and moderate in zona pellucida, in granulosa cells of atretic follicles and mesothelium. PNA staining was mild to moderate in oocytes and in the adventitia and media of medullary arteries. Changes in the LHP of the cystic ovaries were noted; however, there were no differences in these findings between the follicular and luteinized cysts. UEA‐1 reactivity in the cystic ovaries was moderately reduced in the mesothelial and endothelial cells, whereas there was mild reduction in the DBA staining in the granulosa cells. Reaction to RCA‐1 and WGA in the cysts also was decreased in theca interna, zona pellucida and granulosa cells of atretic follicles. Furthermore, endothelium and theca interna in the cystic ovaries presented mild reduction of marcation to SBA, whereas there was decreased reactivity to PNA in the oocytes and adventitia and media layers of the medullary arteries. The results of the current study show that cysts modify the LHP in swine ovaries. These changes of glycoconjugates in many ovarian structures could modify diverse process and may be one of the reasons for decreased fertility in sows.  相似文献   
20.
This study analyses anomalous cases of gestation ending in pregnancy loss during the early foetal period and their effect on progesterone and plasma pregnancy-associated glycoprotein-1 (PAG-1) concentrations. Data derived from a large-scale ultrasound pregnancy diagnosis programme in high producing dairy cows. Over a 3-year period (2004–2007), a very low incidence (0.5%: 15 of 3094) of anomalous pregnancies was recorded. The results revealed that the following anomalies were detected on days 35–41 of gestation in cows carrying singletons with one single corpus luteum: embryo death in eight cows (0.3%); and embryo in the uterine horn contralateral to the corpus luteum in seven cows (0.2%). All these animals suffered pregnancy loss during the early foetal period. In cows carrying dead embryos, no signs of conceptus degeneration were observed on pregnancy diagnosis. Amnion size (approximately 25 mm diameter) and uterine horn fluid contents were estimated to be similar to those of the normal pregnant cows in this period. In the contralateral gestations, live embryos were observed in all ultrasound checks before pregnancy loss. Uterine fluid contents increased in the two cows in which gestation continued for more than a week. In the cases of embryo death but not in those of contralateral gestation, a drop in PAG-1 levels was noted prior to pregnancy loss. Two cows carrying dead embryos increased with time allantoic fluid contents. The PAG-1 values increased with time in one cow bearing a dead embryo (from 2.31 to 6.79 ng/ml) and in two of the contralateral gestations (from 1.66 to 2.33 ng/ml and from 0.39 to 6.79 ng/ml, respectively). Results of this study indicate that the foetal membranes continue to undergo some activity following embryo death, and that contralateral pregnancy may determine failure of the gestation process.  相似文献   
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