Saengkerdsub Suwat, Kim Woo-Kyun, Anderson Robin C, Nisbet David J, Ricke Steven C
Department of Poultry Science, Texas A&M University, College Station, Room 101 Kleberg Center, TX 77843-2472, USA.
Anaerobe. 2006 Apr;12(2):85-92. doi: 10.1016/j.anaerobe.2005.11.006. Epub 2006 Jan 24.
Short-chain volatile fatty acids (VFA) and methane are the products from a wide variety of microorganisms living in the gastrointestinal tract. The objective of this study was to examine effects of feedstuff and select nitro compounds on VFA and methane production during in vitro incubation of laying hen cecal contents and rumen fluid from cattle and sheep. In the first experiment, one of the three nitro compound was added to incubations containing cecal contents from laying hens supplemented with either alfalfa (AF) or layer feed (LF). Both feed material influenced VFA production and acetic acid was the primary component. Incubations with nitro ethanol and 2-nitropropanol (NP) had significantly (P<0.05) higher propionate concentrations than incubations with added nitroethane (NE). The results further indicated that incubations containing LF produced significantly (P<0.05) more butyrate than incubations with added AF. Addition of NP and LF to incubations of avian cecal flora may promote Gram-positive, saccharolytic, VFA-producing bacteria, especially Clostridium spp. which is the predominant group in ceca. Similar to VFA production, both feed materials fostered methane production in the incubations although methane was lower (P<0.05) in incubations with added nitro compound, particularly NE. In experiments 3-8, NE was examined in incubations of bovine or ovine rumen fluid or cecal contents containing either AF or LF. Unlike cecal contents, LF significantly (P<0.05) supported in vitro methane production in incubations of both rumen fluids. The results show that NE impedes methane production, especially in incubations of chicken cecal contents.
短链挥发性脂肪酸（VFA）和甲烷是生活在胃肠道中的多种微生物产生的产物。本研究的目的是检测饲料和特定硝基化合物对蛋鸡盲肠内容物以及牛和羊瘤胃液体外培养期间VFA和甲烷产生的影响。在第一个实验中，将三种硝基化合物之一添加到含有补充了苜蓿（AF）或蛋鸡饲料（LF）的蛋鸡盲肠内容物的培养物中。两种饲料原料均影响VFA的产生，且乙酸是主要成分。与添加硝基乙烷（NE）的培养物相比，添加硝基乙醇和2-硝基丙烷（NP）的培养物中丙酸浓度显著更高（P<0.05）。结果还表明，含有LF的培养物产生的丁酸比添加AF的培养物显著更多（P<0.05）。向禽类盲肠菌群培养物中添加NP和LF可能会促进革兰氏阳性、产糖、产生VFA的细菌生长，尤其是盲肠中的主要菌群梭菌属。与VFA产生情况类似，两种饲料原料在培养物中均促进了甲烷的产生，不过添加硝基化合物（尤其是NE）的培养物中甲烷含量较低（P<0.05）。在实验3至8中，对添加NE的含有AF或LF的牛或羊瘤胃液或盲肠内容物的培养物进行了检测。与盲肠内容物不同，LF在两种瘤胃液的培养物中均显著（P<0.05）支持体外甲烷的产生。结果表明，NE会抑制甲烷的产生，尤其是在鸡盲肠内容物的培养物中。
