Oocyte Morphology from Primordial to Early Tertiary Follicles of Yak     

SJ Yu  YH Yong  Y Cui 《Reproduction in domestic animals》2010,45(5):779-785

The objective of this study was to investigate the developmental morphology of yak oocytes from the primordial follicle to the tertiary follicle. Yak oocytes from resting primordial (n = 6), activated primordial (n = 12), primary (n = 9), secondary (n = 7) and early tertiary (n = 5) follicles were processed and analysed by light and transmission electron microscopy. The resting primordial follicular oocyte was characterized by relatively smooth surface on the oolemma, the accumulation of free and organelle‐related smooth (SER) and rough endoplasmic reticulum (RER), round or oval mitochondria, and polyribosomes on the surface of the RER and throughout the ooplasm. The activated primordial follicular oocyte was dominated by numerous coated pits and coated vesicles on the oolemma, and round mitochondria. Up to the secondary follicular stage the oocyte displayed an increase in the number of microvilli, polyribosome, Golgi complexes and mitochondria with distinct cristae. During the secondary follicular stage, formation of the zona pellucida, development of a desmosome‐like connection between the oocyte and the granulosa cells, formation of the cortical granules in the oocyte and elongated mitochondria in nearly all oocytes were seen. In the early tertiary follicular oocyte, the perivitelline space was present and a decrease in free SER and RER in the ooplasm occurred; finally, the nucleus migrated from an eccentric to a peripheral location. In conclusion, the growth of the yak oocyte is associated with the relocation and modulation of a number of cytoplasmic organelles as well as the development of oocyte‐specific structures such as the zona pellucida, desmosome‐like connection and cortical granules.  相似文献   

Monitoring the health and productivity of farmed ostrich flocks     

SJ MORE 《Australian veterinary journal》1997,75(8):583-587

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Clinical pathology of Australian bluetongue virus serotype 16 infection in Merino sheep     

M. FLANAGAN  SJ JOHNSON  D. HOFFMANN  IG POLKINGHORNE  DJ REID  MA SHEPHERD 《Australian veterinary journal》1993,70(3):101-104

SUMMARY Viraemic blood from an ox naturally infected with Australian bluetongue (BLU) virus serotype 16 was passaged twice in sheep. Twelve 2- to 4-years-old Merino ewes, negative in a bluetongue agar gel Immunodiffusion test, were Inoculated with viraemic blood from the second sheep passage. They were examined for 18 days and compared with a control group. Significant changes in haematological measurements, namely packed cell volume, total white cell count and lymphocyte count, and in plasma enzyme concentrations, namely aspartate transaminase and creatine kinase, occurred in the infected sheep. All Infected sheep became sick. The antibody response, and clinical and necropsy findings were consistent with other reports of mild to moderate disease with Australian BLU serotypes.  相似文献   

Studies on preweaning piglet diarrhoea   总被引：1，自引：0，他引：1  

SJ DRIESEN  PG CARLAND  VA FAHY 《Australian veterinary journal》1993,70(7):259-263

SUMMARY The aim of this study was to determine the cause and risk factors Involved in preweaning piglet diarrhoea. Faecal samples from 2380 diarrhoeic piglets, 5 to 30 days of age, were examined for enteropathogens. Isospora suls oocysts were detected in 53.8% of samples, Escherichia coll in 18.2% and rotavirus in 16.9%. I suis had the widest distribution, being present on 70.9% of 151 piggeries. The onset of diarrhoea occurred mainly between 7 and 14 days (77.5%), peaking at 10 days. Records of 4086 litters from two intensive piggeries were analysed and showed no seasonal variation or effect of sow parity on the incidence of piglet diarrhoea. I suis was the most common enteropathogen associated with diarrhoea in piglets from 5 days of age until weaning.  相似文献   

Salmonella in captive and wild Tasmanian devils (Sarcophilus harrisii) in Tasmania     

SA Michael  M Harlock  SJ Peck  B Lazenby  D Pemberton 《Australian veterinary journal》2020,98(6):239-242

Translocation of Tasmanian devils (Sarcophilus harrisii) is a common strategy for recovery of the species as carried out by the Save the Tasmanian Devil Program. Dasyurids including the endangered Tasmanian devil are well known to asymptomatically harbour the zoonotic bacteria Salmonella enterica in their intestinal tracts. Testing for Salmonella is a routine component of pretranslocation health testing, so a statewide microbiological survey of captive and wild devils was implemented in order to understand prevalence and common Salmonella serotypes, and inform decision-making when positive cultures are identified. This preliminary study identified a significantly higher proportion of Salmonella isolations in wild compared with captive devils. Mississippi and Typhimurium were the most common serotypes, followed by Lexington, Bovismorbificans, Kottbus and Amsterdam. Given the common finding of Salmonella in wild devils and the range of serotypes involved, in addition to numerous isolations in domestic species and humans, it is unlikely that the release of small numbers of captive devils to the wild in Tasmania poses a significant risk to the destination ecosystem. Ongoing monitoring of devils is required as the stress of acclimatisation could predispose devils to clinical disease. Appropriate personal protective attire is pertinent to protect personnel handling animals from this zoonotic infection.  相似文献   

Spectral Properties of Near-Earth Asteroids: Evidence for Sources of Ordinary Chondrite Meteorites     

RP Binzel  SJ Bus  TH Burbine  JM Sunshine 《Science (New York, N.Y.)》1996,273(5277):946-948

Although ordinary chondrite (OC) meteorites dominate observed falls, the identification of near-Earth and main-belt asteroid sources has remained elusive. Telescopic measurements of 35 near-Earth asteroids ( approximately3 kilometers in diameter) revealed six that have visible wavelength spectra similar to laboratory spectra of OC meteorites. Near-Earth asteroids were found to have spectral properties that span the range between the previously separated domains of OC meteorites and the most common (S class) asteroids, suggesting a link. This range of spectral properties could arise through a diversity of mineralogies and regolith particle sizes, as well as through a time-dependent surface weathering process.  相似文献   

Optimizing Electrical Activation of Porcine Oocytes by Adjusting Pre‐ and Post‐Activation Mannitol Exposure Times     

D Kwon  IM Saadeldin  SJ Kim  SJ Park  JT Kang  HJ Park  JH Moon  OJ Koo  G Jang  BC Lee 《Reproduction in domestic animals》2014,49(6):995-999

Modifying electrical activation conditions have been used to improve in vitro embryo production and development in pigs. However, there is insufficient information about correlations of porcine embryo development with oocyte pre‐ and post‐activation conditions. The purpose of this study was to compare the developmental rates of porcine oocytes subjected to different mannitol exposure times, either pre‐ or post‐electrical activation, and to elucidate the reason for the optimal mannitol exposure time. Mannitol exposure times around activation were adjusted as 0, 1, 2 or 3 min. Blastocyst development were checked on day 7. Exposure of oocytes to mannitol for 1 or 2 min before electrical activation produced significantly higher blastocyst rates than exposure for 0 or 3 min. There was no significant difference in blastocyst rates when activated oocytes were exposed to mannitol for 0, 1, 2 or 3 min after electrical activation. While exposure of oocytes to mannitol for 1 min pre‐ and 3 min post‐activation showed significantly higher blastocyst development than 0 min pre‐ and 0 min post‐activation. It also showed higher maintenance of normal oocyte morphology than exposure for 0 min pre‐ and 0 min post‐activation. In conclusion, exposure of oocytes to mannitol for 1 min pre‐ and 3 min post‐activation seems to be optimal for producing higher in vitro blastocyst development of porcine parthenogenetic embryos. The higher blastocyst development is correlated with higher maintenance of normal morphology in oocytes exposed to mannitol for 1 min pre‐ and 3 min post‐activation.  相似文献   

Incidence of lymphoma in a captive-bred colony of hamadryas baboons (Papio hamadryas)   总被引：1，自引：1，他引：0  

LE Graves  A Hennessy  NS Sunderland  SJ Heffernan  SE Thomson 《Australian veterinary journal》2009,87(6):238-243

Objective   To assess the incidence of lymphoma and wasting-related deaths in the National Baboon Colony of Australia and relate it to the presence of simian T-cell lymphotrophic virus 1 (STLV-1) infection.
Design and procedure   The records of all animals that had died since establishment of the National Baboon Colony in Australia were reviewed retrospectively. The clinical signs and histopathological findings were recorded and assessed to determine the involvement of lymphoma in the deaths. The presence of STLV-1 was recorded if known and correlated with the STLV-1 status of the colony.
Results   Of the deaths from disease or illness, 53% were diagnosed as or suspected to be lymphoma, occurring in mature animals with no sex predisposition. The most common presentation was rapidly occurring generalised lymphadenomegaly.
Conclusions   This study has described a relatively high prevalence of lymphoma in a colony of captive-bred baboons, and it is evident that STLV-1 may play a role in the disease. Management practices in baboon colonies need to take into account the possible presence of STLV-1 and aim to reduce the transmission of the virus by preventing sexual contact between positive and negative animals. Lymphoma needs to be considered as one of the more common causes of wasting and death.  相似文献   

An all-island approach to mapping bovine tuberculosis in Ireland   总被引：1，自引：0，他引：1  

McGrath G  Abernethy D  Stringer L  More S 《Irish veterinary journal》2009,62(3):192-197

This study used techniques in Geographical Information Systems (GIS) to explore the spatial patterns of bovine tuberculosis (TB) in the whole island of Ireland over an 11-year period. This is the first time that data pertaining to TB from the Republic of Ireland and Northern Ireland have been collated and examined in an all-Ireland context. The analyses were based on 198, 156 point locations representing active farms with cattle in Northern Ireland and the Republic of Ireland between the years 1996 and 2006. The results consist of a series of maps giving a visual representation of cattle populations and associated detected bTB levels on the island of Ireland over this time interval.  相似文献   

Direct and indirect effects of Johne's disease on farm and animal productivity in an Irish dairy herd     

Richardson E  More S 《Irish veterinary journal》2009,62(8):526-532

Johne's disease (JD) is caused by infection with the organism Mycobacterium avium spp. paratuberculosis, leading to chronic diarrhoea and ill thrift in adult cattle. JD is considered to adversely affect farm performance and profitability. This retrospective case study was undertaken on a single commercial dairy herd in the south west of Ireland. Animal production records were interrogated to assess the effect of JD on milk yield (total kg per lactation), somatic cell count (the geometric mean over the lactation), reasons for culling, cull price and changes in herd parity structure over time. JD groups were defined using clinical signs and test results. One control animal was matched to each case animal on parity number and year. Specific lactations (clinical, pre-clinical and test-positive only) from 1994 to 2004 were compared between JD case and control cows. A significantly lower milk yield (1259.3 kg/lactation) was noted from cows with clinical JD in comparison to their matched control group. Clinical animals had an average cull price of €516 less than animals culled without signs of clinical disease. In contrast, little effect was noted for sub-clinical infections. These direct effects of JD infections, in combination with increased culling for infertility and increasing replacement rates, had a negative impact on farm production. Results from this study provide preliminary information regarding the effects of JD status on both herd and animal-level performance in Ireland.  相似文献