Dunkley K D, Dunkley C S, Njongmeta N L, Callaway T R, Hume M E, Kubena L F, Nisbet D J, Ricke S C
Department of Poultry Science, Texas A&M University, College Station 77843-2472, USA.
Poult Sci. 2007 May;86(5):801-10. doi: 10.1093/ps/86.5.801.
High fiber and nonstarch polysaccharide-based poultry diets have received more interest recently for retaining or promoting beneficial gastrointestinal microbial populations. The objective of this study was to investigate and compare the in vitro potential fermentability of high-fiber feed substrates (HFFS) by laying hen cecal microflora. Feed sources examined included soybean meal, soybean hull, beet pulp, wheat middlings, ground sorghum, cottonseed meal, 100% alfalfa meal, 90% alfalfa + 10% commercial layer ration, 80% alfalfa + 20% commercial layer ration, and 70% alfalfa + 30% commercial layer ration. Cecal contents and HFFS were incubated anaerobically in serum tubes at 39 degrees C for 24 h. Samples from 2 trials were analyzed at 0 and 24 h for short-chain fatty acids (SCFA). Short-chain fatty acids in samples at 0 h were subtracted from 24-h samples to determine the net production of SCFA. In both trials involving HFFS incubations with cecal inocula, acetate production was highest followed by propionate and butyrate whereas isobutyrate and isovalerate production were in trace amounts. In trial 2, detectable valerate production appeared to consistently occur with alfalfa-based HFFS. It was clear that SCFA production was largely dependent upon HFFS, because cecal inoculum alone yielded little or no detectable SCFA production. For HFFS incubations without cecal inocula, acetate production was highest; propionate and butyrate were similar, and isobutyrate, valerate, and isovalerate production were in trace amounts. Polymerase chain reaction-based denaturing gradient gel electrophoresis results from both trials indicated 69 and 71% similarity for comparison of all feed mixtures in trials 1 and 2, respectively. All alfalfa-based HFFS yielded a higher similarity coefficient in trial 2 than in trial 1 with a band pattern of 90% similarity; diets containing 90% alfalfa + 10% commercial layer ration and 80% alfalfa + 20% commercial layer ration in trial 2 formed a subgroup with a 94% microbial similarity coefficient. These data suggest that high fiber sources may contribute to the fermentation and microbial diversity that occurs in the ceca of laying hens.
基于高纤维和非淀粉多糖的家禽日粮最近因能维持或促进有益的胃肠道微生物种群而受到更多关注。本研究的目的是调查和比较蛋鸡盲肠微生物群对高纤维饲料底物（HFFS）的体外潜在发酵能力。所检测的饲料来源包括豆粕、大豆皮、甜菜粕、小麦麸、碎高粱、棉籽粕、100%苜蓿粉、90%苜蓿+10%商品蛋鸡日粮、80%苜蓿+20%商品蛋鸡日粮以及70%苜蓿+30%商品蛋鸡日粮。将盲肠内容物和HFFS在血清管中于39℃厌氧培养24小时。对2个试验的样品在0小时和24小时时分析短链脂肪酸（SCFA）。用24小时样品中的SCFA减去0小时样品中的SCFA，以确定SCFA的净产量。在涉及HFFS与盲肠接种物培养的两个试验中，乙酸盐产量最高，其次是丙酸盐和丁酸盐，而异丁酸盐和异戊酸盐产量微量。在试验2中，基于苜蓿的HFFS似乎始终能检测到戊酸盐产量。很明显，SCFA的产生很大程度上取决于HFFS，因为仅盲肠接种物产生的SCFA很少或无法检测到。对于没有盲肠接种物的HFFS培养，乙酸盐产量最高；丙酸盐和丁酸盐产量相似，而异丁酸盐、戊酸盐和异戊酸盐产量微量。两个试验基于聚合酶链反应的变性梯度凝胶电泳结果表明，试验1和试验2中所有饲料混合物比较的相似性分别为69%和71%。试验2中所有基于苜蓿的HFFS产生的相似系数高于试验1，条带模式相似性为90%；试验2中含有90%苜蓿+10%商品蛋鸡日粮和80%苜蓿+20%商品蛋鸡日粮的日粮形成一个亚组，微生物相似系数为94%。这些数据表明，高纤维来源可能有助于蛋鸡盲肠中发生的发酵和微生物多样性。
