19 research outputs found
Epidemic strain YC2014 of porcine epidemic diarrhea virus could provide piglets against homologous challenge
No evidence of enteric viral involvement in the new neonatal porcine diarrhoea syndrome in Danish pigs
The aim of this study was to investigate whether the syndrome New Neonatal Porcine Diarrhoea Syndrome (NNPDS) is associated with a viral aetiology. Four well-managed herds experiencing neonatal diarrhoea and suspected to be affected by NNPDS were included in a case-control set up. A total of 989 piglets were clinically examined on a daily basis. Samples from diarrhoeic and non-diarrhoeic piglets at the age of three to seven days were selected for extensive virological examination using specific real time polymerase chain reactions (qPCRs) and general virus detection methods. A total of 91.7% of the animals tested positive by reverse transcription qPCR (RT-qPCR) for porcine kobuvirus 1 (PKV-1) while 9% and 3% were found to be positive for rotavirus A and porcine teschovirus (PTV), respectively. The overall prevalence of porcine astrovirus (PAstV) was 75% with 69.8% of the PAstV positive pigs infected with PAstV type 3. No animals tested positive for rotavirus C, coronavirus (TGEV, PEDV and PRCV), sapovirus, enterovirus, parechovirus, saffoldvirus, cosavirus, klassevirus or porcine circovirus type 2 (PCV2). Microarray analyses performed on a total of 18 animals were all negative, as were eight animals examined by Transmission Electron Microscopy (TEM). Using Next Generation de novo sequencing (de novo NGS) on pools of samples from case animals within all herds, PKV-1 was detected in four herds and rotavirus A, rotavirus C and PTV were detected in one herd each. Our detailed analyses of piglets from NNPDS-affected herds demonstrated that viruses did not pose a significant contribution to NNPDS. However, further investigations are needed to investigate if a systemic virus infection plays a role in the pathogenesis of NNPDS
Population Viability Analysis of Black Rhinoceros (Diceros bicornis michaeli) in
Abstract Drastic decline of the black rhinoceros population both in numbers and range distribution have created a puzzle on its long term survival. We developed simulation models to identify crucial anthropogenic parameters that are essential for the successful development of conservation actions of this species in Lake Nakuru National Park under different scenarios. The roles of multiple anthropogenic parameters were evaluated to assess changes affecting population declines and extinction risk. Population Viability Analysis (PVA) simulations were done using individualbased program. A baseline simulation allowed for the assessment of the status of the species based on estimates of extinction risk and population declines under current conditions of abundance and habitat availability. The baseline simulation showed that Lake Nakuru National Park subpopulation has 0.00 probability of extinction during the next seventy five years. However, continuing threats, including declines in abundance and browse unavailability, make this species highly vulnerable to any change. Sensitivity analysis of anthropogenic impacts showed that small increases in habitat loss (2%) and population harvesting (3%) had drastic effects on population decline with a 100% probability of extinction. Our findings shows the need for conservation actions aimed at preventing poaching activities, modulating translocation programs and promoting the conservation of available black rhino habitats