Effect of commercial slow-release urea product on in vitro rumen fermentation and ruminal microbial community using RUSITEC technique  

作　　者：Yongmei Guo Ling Xiao Long Jin Sumei Yan Dongyan Niu Wenzhu Yang 

机构地区：[1]Inner Mongolia Key Laboratory of Animal Nutrition and Feed Science,College of Animal Science,Inner Mongolia Agricultural University,Hohhot 010018,Inner Mongolia,China [2]Agriculture and Agri-Food of Canada,Lethbridge Research and Development Centre,Lethbridge,AB T1J 4B1,Canada [3]Hangzhou King Techina Feed Co.,Ltd,Hangzhou City,China [4]College of Veterinary Medicine,University of Calgary,2500 University Dr.NW,Calgary,AB T2N 1N4,Canada

出　　处：《Journal of Animal Science and Biotechnology》2022年第5期1499-1512,共14页畜牧与生物技术杂志（英文版）

基　　金：financially supported by the Alberta Agriculture and Forestry(#2015E006R);King Techina Feed Co.,Ltd.(Hangzhou, China)。

摘　　要：Background:The objectives of this study were to determine the effect of commercial slow-release urea(SRU)on in vitro fermentation characteristics,nutrient digestibility,gas production,microbial protein synthesis and bacterial community using a rumen simulation technique(RUSITEC).The experiment was a completely randomized design with four treatments and four replications of each treatment.Treatments were:control diet(no SRU addition),control diet plus 0.28%SRU(U28),or plus 0.56%SRU(U56),and control diet that was modified substituting a part of soybean meal equivalent to 0.35%SRU(MU35;dry matter[DM]basis).The experiment consisted of 8 d of adaptation and 7 d of data and sample collection.Rumen inoculum was obtained from three ruminally fistulated Angus cows fed the same diet to the substrate incubated.Results:Digestibility of DM,organic matter(OM),crude protein(CP),fibre and starch was not affected,but daily production of gas(P<0.07)and methane(P<0.05)was quadratically increased with increasing SRU supplementation.The increase of SRU addition did not affect fermentation pH and total volatile fatty acid(VFA)production,whereas linearly(P<0.01)decreased proportion of propionate,and linearly(P<0.01)increased acetate to propionate ratio and ammonia nitrogen(N)concentration.The microbial N efficiency was also linearly(P<0.03)improved with increasing supplementation of SRU.In comparison with control diet,the dietary substitution of SRU for part of soybean meal increased(P<0.05)the digestibility of DM,OM and CP and decreased(P<0.02)the total gas production.The total VFA production and acetate to propionate ratio did not differ between control and MU35,whereas the proportion of butyrate was lower(P<0.05)and that of branched-chain VFA was greater(P<0.05)with MU35 than control diet.Total and liquid-associated microbial N production as well as ammonia N concentration were greater(P<0.03)with MU35 than control diet.Observed operational taxonomic units(OTUs),Shannon diversity index,and beta diversity of the microbial community d

关 键 词：Artificial rumen system Dairy cow diet Fermentation characteristics Slow-release urea 

分 类 号：S816[农业科学—饲料科学]