Different Culture Media Requirements of IVF and Nuclear Transfer Bovine Embryos

Important differences exist between in vitro fertilized (IVF) and nuclear transfer (NT) bovine embryos. Studies have shown that although in vitro development is comparable, post-implantation survival is greatly reduced in NT embryos. In this study, we compare serum and bovine serum albumin (BSA) supplementation during oocyte maturation and embryo culture of IVF and NT embryos. In experiment 1, oocytes and embryos were randomly distributed into different treatment groups consisting of synthetic oviductal fluid (SOF) medium supplemented with either serum, fatty acid-free BSA (FAF) or fraction V BSA during maturation and/or culture to assess IVF embryo development. In experiment 2, oocytes were matured in SOF + serum or SOF + FAF and reconstructed embryos were cultured in SOF + FAF to assess NT embryo development. Among the IVF treatment groups, a greater number of blastocysts were observed in the steer serum (SER) group (IVM and IVC in SOF + serum) on day 6; however, no significant differences were seen in blastocyst development from day 8 onwards. Hatching frequencies on days 8 and 9 were significantly greater in groups with serum, with the exception of FAF (IVM and IVC in SOF + FAF) on day 9. For the NT treatment groups, the presence of serum during IVM resulted in a higher proportion of MII oocytes and increased blastocyst development and hatching rates were compared with supplementation of FAF. These results indicate that both serum and FAF provide comparable embryo development for IVF but not for NT bovine embryos.     

补饲马铃薯藤对山羊生长性能、消化率和胴体特征的影响

本研究旨在探讨马铃薯藤饲喂水平对山羊生长性能、养分消化率和胴体特征的影响.试验将平均初始体重为(14.42±0.24)kg的40头山羊随机分为4组,每组5个重复,每个重复2头.T1组仅饲喂干草,T2组饲喂干草+100％马铃薯藤,T3组饲喂干草+50％马铃薯藤+50％浓缩料,T4组饲喂100％浓缩料.在为期10周的饲养试...     

留茬高度对人工草地牧草产量及质量的影响

试验对黑麦草／白三叶混播草地在不同留茬高度下的生产特性进行了分析研究,研究结果表明,草地牧草的枯死率与留茬高度呈正比关系,在不同留茬高度下,草地牧草青绿物质的生长速度和产量呈抛物线形式变化;青绿牧草产量占牧草总产量的百分比随留茬高度的上升而下降,而死亡物质的数量占牧草产量的百分比随留茬高度的上升而增加。     

降钙素对健康马试验性高血钙的快速应答

钙有重要的生理功能,对马钙平衡的研究已经取得了很大的进步,但对马的降钙素（CT）的了解却有限,是由于缺少验证性试验。为检测马的CT对高钙离子（Ca2＋）浓度的应答,试验按5mg·kg^-1加入葡萄糖酸钙,制成23%葡萄糖酸钙溶液,对总重500kg的10匹健康马注入120mL该溶液4min以上,以诱导高血钙。对4匹马注入0.9% NaCl 120mL为对照组。已证实人类特有CT放射免疫分析可以应用于马。试验结果表明,注入4min葡萄糖酸钙溶液后血清Ca^2＋浓度从6.2±0.3mg·dL^-1上升到9.9±0.5mg·dL^-1,且变化差异极显著（P〈0.01）。2min后血清CT浓度从16.7±8.0pg·mL^-1上升到87.1±55.8pg·mL^-1,而4min后血清CT浓度则上升到102.5±51.1pg·mL^-1,且差异极显著（P〈0.01）。20min后血清CT浓度恢复到其基础水平,而血清Ca^2＋浓度须经40min才恢复到其基础水平。在高血钙情况下,CT浓度仍恢复到基础水平,表明了甲状腺C细胞中CT的耗竭。安静状态下CT值异常升高（高于40pg·mL^-1）但对照组的血清Ca^2＋浓度和CT浓度没有显著变化。由放射免疫分析法测定的CT变异系数低于11.9%。     

Chronological Appearance of Apoptosis in Bovine Embryos Reconstructed by Somatic Cell Nuclear Transfer from Quiescent Granulosa Cells

Efficiency of cloning has remained low and in spite of attempts to improve this technology, many reconstructed embryos do not implant or are lost during early pregnancy. Chromosomal aberrations, deviant gene expression patterns and abnormal regulation of cell death may be involved in this increased early embryonic loss. Here, we investigate the chronological onset of both apoptotic changes in nuclear morphology and DNA degradation [detected by transferase-mediated dUTP nick-end labelling (TUNEL) reaction] in bovine two-cell- to blastocyst-stage embryos. Such embryos were generated either by reconstruction with nuclear transfer from quiescent granulosa cells or by regular in vitro embryo production. Nuclear condensation was observed from the two-cell stage and TUNEL labelling was observed from the six-cell stage in reconstructed embryos, whereas nuclear condensation was evident from the eight-cell stage and TUNEL labelling from the 13-cell stage in embryos derived in vitro. Furthermore, reconstructed embryos displayed elevated ratios of embryos containing apoptotic nuclei at pre-compaction stages and higher indices of apoptotic nuclei in morula and blastocyst stages when compared with in vitro-produced embryos.     

Cutaneous hemangioma in a giant panda (Ailuropoda melanoleuca).

An adult male giant panda (Ailuropoda melanoleuca) was presented with a cutaneous mass ventral to the eye. The animal was anesthetized and the mass was surgically excised. Histopathologic examination determined that the mass was a benign cavernous hemangioma, the first reported case in a giant panda.