CAJ | 학술논문

本试验旨在研究饲粮添加烟酸对水牛瘤胃发酵指标及微生物区系的影响。试验选用36头健康状况良好,体重接近的杂交泌乳水牛,随机分为4个组,分别在基础饲粮中添加0(对照)、4、8、12 g/d烟酸,烟酸与精料混合饲喂,进行预试期14 d,正试期42 d的饲养试验。试验结束后,胃管采集瘤胃液测定瘤胃发酵指标,并采用Illumina Miseq PE250高通量测序平台分别测序瘤胃细菌和甲烷菌16S rRNA基因以确定二者区系组成。结果表明：1)与对照组相比,添加12 g/d烟酸提高了水牛日均采食量(P<0.05)和瘤胃液氨态氮浓度(P>0.05),烟酸各组均显著降低了瘤胃液总挥发性脂肪(TVFA)浓度(P<0.05),但未显著影响瘤胃液pH(P>0.05)。2)水牛瘤胃内细菌在门水平上主要以拟杆菌门和厚壁菌门为主,科水平上为普雷沃氏菌科和黄杆菌科；甲烷菌以甲烷短杆菌属为主,占90%以上,其次为甲烷球菌属和热原体属,水牛瘤胃微生物区系总体上与奶牛等其他利用植物纤维的反刍动物相似。3)与对照组相比,饲粮添加烟酸显著降低了瘤胃内厚壁菌门的比例( P<0.05),显著提高了黄杆菌科细菌的比例( P<0.05),但对瘤胃甲烷菌区系无显著影响( P>0.05)。饲粮添加烟酸改变了水牛瘤胃发酵指标和微生物区系组成,瘤胃发酵指标的变化除了与烟酸对水牛热应激的缓解和消化吸收的影响有关,还与烟酸添加对瘤胃细菌区系的影响有关。
본시험지재연구사량첨가연산대수우류위발효지표급미생물구계적영향。시험선용36두건강상황량호,체중접근적잡교비유수우,수궤분위4개조,분별재기출사량중첨가0(대조)、4、8、12 g/d연산,연산여정료혼합사위,진행예시기14 d,정시기42 d적사양시험。시험결속후,위관채집류위액측정류위발효지표,병채용Illumina Miseq PE250고통량측서평태분별측서류위세균화갑완균16S rRNA기인이학정이자구계조성。결과표명：1)여대조조상비,첨가12 g/d연산제고료수우일균채식량(P<0.05)화류위액안태담농도(P>0.05),연산각조균현저강저료류위액총휘발성지방(TVFA)농도(P<0.05),단미현저영향류위액pH(P>0.05)。2)수우류위내세균재문수평상주요이의간균문화후벽균문위주,과수평상위보뢰옥씨균과화황간균과；갑완균이갑완단간균속위주,점90%이상,기차위갑완구균속화열원체속,수우류위미생물구계총체상여내우등기타이용식물섬유적반추동물상사。3)여대조조상비,사량첨가연산현저강저료류위내후벽균문적비례( P<0.05),현저제고료황간균과세균적비례( P<0.05),단대류위갑완균구계무현저영향( P>0.05)。사량첨가연산개변료수우류위발효지표화미생물구계조성,류위발효지표적변화제료여연산대수우열응격적완해화소화흡수적영향유관,환여연산첨가대류위세균구계적영향유관。
This study was conducted to study the effects of dietary addition of niacin on ruminal fermentation indexes and microflora of water buffaloes. Thirty-six healthy hybrid water buffaloes with similar body weight were selected and divided into four groups randomly. The four groups were fed the same basal diet but added with 0 ( control) , 4, 8 and 12 g/d, respectively. Niacin was mixed in concentrate to feed. The advanced ex-periment feeding period was 14 days and the formal experimental period was 42 days. At the end of experi-ment, rumen fluid samples were taken from rumen by stomach tube to test the ruminal fermentation indexes, 16S rRNA genes of ruminal bacteria and methanogen were tested to determine microbial community by Illumi-na Miseq PE250 high-throughput sequencing. The results showed as follows:1) compared with control group, the addition of 12 g/d of niacin increased average daily feed intake ( P<0.05) and rumen fluid ammonia con-centration ( P>0.05) , niacin groups significantly decreased rumen fluid total volatile fatty acid ( TVFA) con-centration (P<0.05), but the rumen fluid pH was not significantly influenced (P>0.05). 2) Water buffalo ruminal bacterial community was dominated by Bacteroidetes and Firmicutes at phyla level, Prevotellaceae and Fibrobacteraceae at family level, while ruminal methanogen community was dominated by Methanobrevibacter ( over 90%) at genus level, followed by Methanosphaera and Thermoplasma. Water buffalo ruminal bacteria and methanogen community composition was generally similar with other ruminants which could utilize plant fi-ber. 3) Compared with control group, the addition of niacin significantly decreased ruminal Firmicutes the pro-portion ( P<0.05) , and significantly increased ruminal Fibrobacteraceae proportion ( P<0.05) , but there was no influence on methanogen community ( P>0.05) . In conclusion, the addition of niacin changes ruminal fer-mentation indexes and microflora of water buffaloes, the changes of ruminal fermentation indexes on one hand are related with release on heat stress and improvement on digestion of niacin, on another hand are related with the change of ruminal microflora.