Effect of the Pietrain breed used as terminal boar on Post-weaning Multisystemic Wasting Syndrome (PMWS) in the offspring in four PMWS-affected farms

The aim of this study was to determine the potential risk factors for PMWS at the individual pig level and assess the effect of the Pietrain paternal genetic background of the animals in a cohort study. The survey was set up in four PMWS-affected farms with 2 repetitions (batches) per farm. A representative sample of 60 pigs per batch, stratified according to the paternal genetic background (Pietrain: yes vs. no), was randomly selected after farrowing. The representative cohort was divided into 8 batches and the pigs were individually monitored from birth to slaughter. Survival analysis was used to determine the factors related to the time to PMWS. The litter-cluster effect was taken into account using the marginal Cox model (robust estimation of the covariance matrix) and the gamma shared frailty model which were compared.No protective effect of the Pietrain breed on the time to PMWS and the proportion of affected pigs in the offspring was found in this study. Piglets showing low circovirus type 2 (PCV2) titres at 7 weeks-old with no subsequent seroconversion and piglets from PCV2 negative sows were most likely to be affected by PMWS (HR=7.0 and 2.8, respectively). Active infection of the pregnant dams with parvovirus was related to an increased risk of PMWS in the offspring (HR=2.3). Neck injuries due to poorly performed injections in the dams were associated with an increased risk of PMWS with the marginal model (HR=2.1). Oxytocin injection (dams) during farrowing was protective against PMWS in the offspring (HR=0.6).     

Study on Expression and Preliminary Immunocompetence of CIC Protein Containing Molecular Adjuvants

To express CTB-IsdBid-Clfais(CIC) protein and evaluate its immunogenicity, CTB (as a molecular adjuvant) could be tandem linked with IsdBid-Clfais gene by the overlapping PCR method, then CTB-IsdBid-Clfais(CIC) was inserted into pET-32a(+) vector to construct recombinant plasmids pET-32a(+)-CTB-IsdBid-Clfais. The recombinant plasmids pET-32a(+)-CTB-IsdBid-Clfais were transformed into Escherichia coli (E.coli) BL21 to express the CTB-IsdBid-Clfa(CIC) protein, the CIC expression protein and its immune activity were detected by Western blotting and ELISA,respectively. The results showed that the length of CIC gene were 2 072 bp, and CIC was correctly inserted into the pET-32a(+) plasmids, the pET-32a(+)-CTB-IsdBid-Clfais recombinant plasmids were successfully constructed. Western blotting result confirmed that the molecular weight of CIC proteins was 95.9 ku, which were correctly expressed by E.coli BL21 with pET-32a (+)-CTB-IsdBid-Clfais plasmids. ELISA results showed that there was no significant difference among the CIC, IsdBid and Clfais protein groups (P>0.05), and there was extremely significant difference between CIC and BSA protein groups (P<0.01). In conclusion, the pET-32a(+)-CTB-IsdBid-Clfais recombinant plasmids were successfully constructed, CIC proteins were correctly expressed, and were able to react with serum from mice immunized with IsdBid and Clfais,respectively,therefore, CIC proteins had strong immune activity.     

半胱胺的生物学作用及应用

半胱胺具有多种生物学功能,如耗竭生长抑素,影响糖、蛋白质和脂肪的代谢,抗氧化和氧化作用,提高免疫功能。本文综述了半胱胺的生物学功能和应用情况。     

Investigation of biosecurity risks associated with the feed delivery: A pilot study

This study explored potential biosecurity issues related to the delivery of feed to commercial farms. A pilot study was conducted to collect information about the day-to-day feed delivery, including biosecurity concerns at the level of the feed truck, the driver, and the farm. In addition, a reusable rubber boot was tested in an effort to increase the proportion of farms at which truck drivers wore clean footwear, and to explore an alternative to the standard plastic disposable boots that may be unsafe in winter conditions. Most farms did well in terms of proper dead-stock management and keeping the farm lane and feed bin areas clean. The provision of reusable rubber boots significantly increased the proportion of deliveries in which the driver wore clean footwear.     

Ultrasound-guided posterior extraconal block in the dog: anatomical study in cadavers

Objective

To describe a novel ultrasound-guided posterior extraconal block in the dog.