美国、加拿大生物安全三级动物实验室考察报告

美国、加拿大对ABSL-3的设计均为三层。下方的尸体、污物处理层和上方的设备层及中间的动物实验室层。设计比较科学，人性化，其高度均达6m以上。配备有索道和电葫芦，以供动物移动使用；电动解剖台可按电钮升降调节解剖台的高度，动物尸体处理由Renderer cooker尸体处理器经高压、粉碎、干燥成肉陷状颗粒，粪便及污水收集在三个5000L容量的高压灭菌处理器中高压灭菌处理，设施内的灭菌采用环保的过氧化氢消毒设备。     

Transcutaneous ultrasound over the right flank to diagnose mid- to late-pregnancy in the dairy cow

Objective   To investigate the practical application and image quality of transcutaneous ultrasonography across the right flank for the diagnosis of mid- to late-gestation in cattle.
Procedure   Dairy cows of known pregnancy status were used to establish criteria for the identification of mid- to late-stage pregnancy by transcutaneous ultrasonography. Factors involved in the practical application of transcutaneous ultrasound for routine use in pregnancy diagnosis in dairy cattle were also examined.
Results   Transcutaneous ultrasound, using a 3.5-MHz sector transducer applied over the caudodorsal right flank fold, allowed rapid and detailed visualisation of bovine pregnancy (i.e. fetus, fetal fluids, placentomes and/or fetal membranes) and could be used to establish criteria for the diagnosis of pregnancy. The commonly available cattle holding facilities of the herringbone dairy, rotary herringbone dairy, AI race or crush, and walk-through dairy all allow safe access to the right flank of a dairy or beef cow. However, transcutaneous scanning over the right flank is difficult in modern rotary turnstile dairies.
Conclusion   A 3.5-MHz sector transducer applied over the caudodorsal right flank fold allows detailed visualisation of the bovine fetus in most types of cattle-holding facilities. Further investigation of the sensitivity and specificity of this technique over the entire gestation period and its possible use in ageing of the bovine fetus is merited.