Retrospective evaluation of occlusion of patent ductus arteriosus with hemoclips in 20 dogs

Twenty dogs with patent ductus arteriosus occluded with Hemoclips were evaluated with a mean follow-up time of 799.4 days (range, 83 to 3,580 days). Significant decreases were found between pre- and postsurgical means for vertebral heart size and for echocardiographic left atrial/aortic-root ratios and percent fractional shortening (%FS). Despite a good clinical outcome, six of 20 dogs had persistent cardiomyopathy of overload with diminished %FS (28% or less) at follow-up. One dog had residual ductal flow identified five days postoperatively. Subsequent evaluations in this case at 60, 144, 226, 344, and 560 days postoperatively demonstrated gradually diminishing ductal flow. The remaining 19 dogs did not recanalize.     

Management of inappetant sheep during export by sea

In the first of 2 experiments, a simulated voyage was conducted to examine the effects of various treatments on bodyweight change and feeding frequency of inappetant sheep at the end of lot-feeding (non-feeders). The treatments, applied during simulated shipping, were: normal quantities of feed and length of troughs; extra trough length; extra feed. Adult Merino wethers (n = 108) were used in each treatment. A voyage to the Middle East was then conducted to establish whether shipboard mortality could be reduced by separating non-feeders (n = 305) from feeders (n = 5,620) late in the feedlot hase and housing the groups separately aboard ship. A control group of non-feeders (n = 215) mixed with feeders (n = 5,732) was used for comparison. Bars (marker bars), containing a coloured dye, were attached to feed troughs to mark sheep that fed. Most non-feeders (82%) began eating when placed in shipping pens in both studies. However, there was no significant difference in percentage of sheep that fed between non-feeders given extra trough length or extra feed compared with non-feeders given standard management at any stage of simulated shipping. There was no significant difference in mean bodyweights between treatment groups on days 1, 8 and 15 of simulated shipping. Differences in bodyweight on d 22 were probably associated with different levels of gut fill. Death rates were not significantly different in separated and control groups (1.1%, 0.9%, P = 0.6) in the voyage of 14 d to the Middle East.(ABSTRACT TRUNCATED AT 250 WORDS)     

桉树人工育种方法学

引言改良商业林的种植材料是一个长期不断的过程。种子最初是从自然林分和人工林的实生苗中采取;后来是采用林木选优,它是根据树木的特征,如材积、早期生长情况或抗病性来选择。可通过选出最好的基因进行组合,以进一行提高控制杂交群体增益。