Consuming fermented distillers＇ dried grains with solubles (DDGS) feed reveals a shift in the faecal microbiota of growing and fattening pigs using 454 pyrosequencing

The objective of this study was to investigate pig fed by Bacillus coagulans-fermented distillers＇ dried grains with solubles （DDGS） on the faecal microbial composition and diversity using 454 pyrosequencing. Healthy crossbred （Durocx Yorkshirex Landrace） growing and fattening pigs （n=48）, with an average initial body weight of 65 kg, were divided into two groups （24 replicates per group; four pens per group; six pigs per pen）, and given either DDGS feed as the control, or B. coagulans-fermented DDGS feed as the treatment. Faecal samples were collected on day 0, 7, 14, 21, and 28. DNA was extracted, and the V3-V6 region of the 16S rRNA gene was amplified. The fermented DDGS feed affected the relative abundance of bacteria populations at the phylum, genus, and species levels. At the genus level, the consumption of fermented DDGS feed led to higher relative abundances of faecal Prevotella, Lactobacillus, Clostridium, Bifidobacterium, Roseburia, and Bacillus, and lower relative abundances of faecal Escherichia, Ruminococcus, Dialister, unclassified Lachnospiraceae, unclassified Ruminococcaceae, and unclassified Enterobacteriaceae than in the control. At the species level, the consumption of fermented DDGS feed led to higher relative abundances of faecal Prevotella sp., Lactobacillus johnsonii, Lactobacillus fermentum, Lactobacillus mucosae, Lactobacillus reuteri, Clostridium butyricum, Bifidobacterium sp., and Roseburia sp., and lower relative abundances of faecal Prevotella copri, Escherichia coil, Ruminococcus gnavus, Ruminococcus flavefaciens, and Dialister sp. than in the control. Principal coordinates analysis indicated a distinct separation in the faecal microbial communities of pigs that were fed the fermented and unfermented DDGS feed. Fermented DDGS feed significantly increased the average daily gain （ADG） of pigs, and significantly decreased the average daily feed intake （ADFI） of feed and feed/gain （F/G）. Thus, our results demonstrate a beneficial shift in the faecal microbiota of pigs consuming fermented DDGS feed, with potential applications in livestock production.

基于细胞内应变评估的卵母细胞去核方法及在机器人化克隆中的应用

自1996年第一只克隆羊诞生,克隆技术就由于其在动物育种方面的巨大潜力而得到了大量关注。体细胞核移植技术是动物克隆的核心,其操作过程非常复杂,不可避免地造成细胞内损伤。通常来说,只有不到1%的重构胚胎能够发育成克隆动物,克隆的低成功率是制约其广泛应用的主要原因之一。为此,本文提出了一种基于细胞内应变评估的卵母细胞去核方法,来减少体细胞核移植中的潜在细胞内损伤,从而提高克隆成功率。首先,论文根据细胞内速度场计算细胞内应变,进而将内应变作为评价标准来优化去核操作;在此基础上,开发了一套机器人批量体细胞核移植系统,用于实现机器人化克隆。实验结果表明,本文方法将体细胞核移植后的胚胎囊胚率从10.0%提高到20.8%,并成功获得17头克隆小猪,这是世界首批由机器人完成克隆操作获得的克隆动物。对比手动核移植操作,本文将克隆成功率从平均0.73%提升到了2.50%,大幅提升了克隆效率。与此同时,基于细胞内应变的去核方法有望应用于其他生物操作,并建立一种通用的减少细胞内损伤的细胞操作规范。