Kraatz M, Taras D, Männer K, Simon O
Institute of Animal Nutrition, Faculty of Veterinary Medicine, Free University Berlin, Berlin, Germany.
J Anim Physiol Anim Nutr (Berl). 2006 Oct;90(9-10):361-8. doi: 10.1111/j.1439-0396.2005.00594.x.
Two 6-week feeding trials were conducted on a total of 112 newly weaned piglets to examine the recently reported growth promoting effects of dietary rare earth elements (REE) in European pig production. Rare earth element-diets were supplemented with a REE-citrate premix of lanthanum and the light lanthanoides cerium, praseodymium and neodymium at 200 mg/kg for 6 weeks after weaning. Overall for both trials, growth performance of REE-citrate and control fed piglets did not differ significantly (p > 0.05). An early enhancive tendency for REE-citrate in trial 1 (feed conversion ratio, FCR -3%, p = 0.15) proved irreproducible in trial 2. In the late period of trial 1, in-feed addition of REE-citrate significantly impaired piglet performance (FCR + 8%, p = 0.01). A cultivation-independent molecular approach, polymerase chain reaction-denaturing gradient gel electrophoresis was further applied to assess REE induced alterations in the predominant faecal microbiota from weaning pigs. Calculation of various ecological characteristics does not indicate (p > 0.05) an often discussed selective effect on local microbial composition of dietary REE.
对总共112头新断奶仔猪进行了两项为期6周的饲养试验，以研究最近报道的日粮稀土元素（REE）在欧洲养猪生产中的促生长作用。在断奶后6周内，稀土元素日粮添加了一种柠檬酸稀土预混料，其中含有镧以及轻稀土元素铈、镨和钕，添加量为200毫克/千克。总体而言，在两项试验中，饲喂柠檬酸稀土的仔猪和对照仔猪的生长性能没有显著差异（p>0.05）。试验1中柠檬酸稀土早期的增强趋势（饲料转化率，FCR -3%，p = 0.15）在试验2中未得到重现。在试验1后期，日粮中添加柠檬酸稀土显著损害了仔猪性能（FCR + 8%，p = 0.01）。一种不依赖培养的分子方法，即聚合酶链反应-变性梯度凝胶电泳，被进一步用于评估稀土元素对断奶仔猪主要粪便微生物群的诱导变化。对各种生态特征的计算未表明（p>0.05）日粮稀土元素对局部微生物组成常被讨论的选择性作用。
