This study was conducted to investigate the phylogenetic diversity of archaea in the rumen of adult and elderly yaks. Six domesticated female yaks, 3 adult yaks （（5.3±0.6） years old）, and 3 elderly yaks （（1...This study was conducted to investigate the phylogenetic diversity of archaea in the rumen of adult and elderly yaks. Six domesticated female yaks, 3 adult yaks （（5.3±0.6） years old）, and 3 elderly yaks （（10.7±0.6） years old）, were used for the rumen contents collection. Illumina MiSeq high-throughput sequencing technology was applied to examine the archaeal composition of rumen contents. A total of 92 901 high-quality archaeal sequences were analyzed, and these were assigned to 2 033 operational taxonomic units （OTUs）. Among these, 974 OTUs were unique to adult yaks while 846 OTUs were unique to elderly yaks; 213 OTUs were shared by both groups. At the phylum level, more than 99% of the obtained OTUs belonged to the Euryarchaeota phylum. At the genus level, the archaea could be divided into 7 archaeal genera. The 7 genera （i.e., Methanobrevibacter, Methanobacterium, Methanosphaera, Thermogymnomonas, Methanomicrobiu, Meth- animicrococcus and the unclassified genus） were shared by all yaks, and their total abundance accounted for 99% of the rumen archaea. The most abundant archaea in elderly and adult yaks were Methanobrevibacterand Thermogymnomonas, respectively. The abundance of Methanobacteria （class）, Methanobacteriales （order）, Methanobacteriaceae （family）, and Methanobrevibacter （genus） in elderly yaks was significantly higher than in adult yaks. In contrast, the abundance of Ther-mogymnomonas in elderly yaks was 34% lower than in adult yaks, though the difference was not statistically significant. The difference in abundance of other archaea was not significant between the two groups. These results suggested that the structure of archaea in the rumen of yaks changed with age. This is the first study to compare the phytogenetic differences of rumen archaeal structure and composition using the yak model.展开更多
This experiment was conducted to investigate the effects of live yeast and yeast cell wall polysaccharides on growth performance,rumen function and plasma lipopolysaccharides(LPS) content and immunity parameters of be...This experiment was conducted to investigate the effects of live yeast and yeast cell wall polysaccharides on growth performance,rumen function and plasma lipopolysaccharides(LPS) content and immunity parameters of beef cattle.Forty Qinchuan cattle were randomly assigned to one of four treatments with 10 replicates in each treatment.The dietary treatments were: control diet(CTR),CTR supplemented with 1 g live yeast(2×10^10 live cell g^-1 per cattle per day(YST1),CTR supplemented with 2 g live yeast per cattle per day(YST2) and CTR supplemented with 20 g of yeast cell wall polysaccharides(30.0%≤β-glucan≤35.0%,and 28.0%≤mannanoligosaccharide≤32.0%) per cattle per day(YCW).The average daily gain was higher(P=0.023) and feed conversion ratio was lower(P=0.042) for the YST2 than the CTR.The digestibility of neutral detergent fiber(P=0.039) and acid detergent fiber(P=0.016) were higher in yeast supplemented groups.The acetic acid:propionic acid of the YST2 was lower compared with the CTR(P=0.033).Plasma LPS(P=0.032),acute phase protein haptoglobin(P=0.033),plasma amyloid A(P=0.015) and histamine(P=0.038) were lower in the YST2 compared with the CTR.The copies of fibrolytic microbial populations such as Fibrobacter succinogenes S85,Ruminococcus albus 7 and Ruminococcus flavefaciens FD-1 of the YST2 were higher(P<0.001),while the copies of typical lactate producing bacteria Streptococcus bovis JB1 was lower(P<0.001) compared with the CTR.Little differences were observed between the CTR,YST1 and YCW in growth performance,ruminal fermentation characteristics,microbial populations,immunity indices and total tract nutrient digestibility.It is concluded that the YST2 could promote fibrolytic microbial populations,decrease starch-utilizing bacteria,reduce LPS production in the rumen and LPS absorption into plasma and decrease inflammatory parameters,which can lead to an improvement in growth performance in beef cattle.展开更多
A common problem in rabbit production is the occurrence of digestive disorders just after weaning, and fiber is well known to be bcncficiai for rabbit gastrointestinal health. In order to test the hypothesis that w...A common problem in rabbit production is the occurrence of digestive disorders just after weaning, and fiber is well known to be bcncficiai for rabbit gastrointestinal health. In order to test the hypothesis that whether the good points of fiber increases with its dietary content, three isoenergetic and isonitrogenous diets and ninety mixed-sex New Zealand rabbits weaned 35-d-old were used. The results can be concluded as following： （1） Average daily feed intake （ADFI） tended to increase （i〉=0.058） while average daily gain （ADG） （p=0.001） and feed conversion ratio （FCR） （p〈0.001） deteriorated with increasing dietary ADF content. The highest morbidity was observed in the rabbits fed the highest dietary ADF concentration. （2）A decreasing coefficient of total tract apparent digestibility （CTTAD） of dry matter （DM） and crude protein （CP） was obtained with the increase of dietary fiber level （p〈0.001 and =0.003）. （3） A significant negative effect of treatments on sucrase and maltase activities in the jejunum was observed （p=0.001 and 0.003）. （4） The volatile fatty acid （VFA） concentration （p=0.011） and butyric acid （% total VFA） （P=0.001） dropped while the NH3-N concentration （P〈0.001）, pH （P=0.004） and acetic acid （% total VFA） （P〈0.001） increased with increasing dietary ADF. It was concluded that high fiber level was unfavorable to the rabbits in the first two weeks after weaning.展开更多
基金the International Cooperation Project of the Ministry of Sciences and Technology of China(2014DFA32860)the National Natural Science Foundation of China(31402104)for their financial support
文摘This study was conducted to investigate the phylogenetic diversity of archaea in the rumen of adult and elderly yaks. Six domesticated female yaks, 3 adult yaks （（5.3±0.6） years old）, and 3 elderly yaks （（10.7±0.6） years old）, were used for the rumen contents collection. Illumina MiSeq high-throughput sequencing technology was applied to examine the archaeal composition of rumen contents. A total of 92 901 high-quality archaeal sequences were analyzed, and these were assigned to 2 033 operational taxonomic units （OTUs）. Among these, 974 OTUs were unique to adult yaks while 846 OTUs were unique to elderly yaks; 213 OTUs were shared by both groups. At the phylum level, more than 99% of the obtained OTUs belonged to the Euryarchaeota phylum. At the genus level, the archaea could be divided into 7 archaeal genera. The 7 genera （i.e., Methanobrevibacter, Methanobacterium, Methanosphaera, Thermogymnomonas, Methanomicrobiu, Meth- animicrococcus and the unclassified genus） were shared by all yaks, and their total abundance accounted for 99% of the rumen archaea. The most abundant archaea in elderly and adult yaks were Methanobrevibacterand Thermogymnomonas, respectively. The abundance of Methanobacteria （class）, Methanobacteriales （order）, Methanobacteriaceae （family）, and Methanobrevibacter （genus） in elderly yaks was significantly higher than in adult yaks. In contrast, the abundance of Ther-mogymnomonas in elderly yaks was 34% lower than in adult yaks, though the difference was not statistically significant. The difference in abundance of other archaea was not significant between the two groups. These results suggested that the structure of archaea in the rumen of yaks changed with age. This is the first study to compare the phytogenetic differences of rumen archaeal structure and composition using the yak model.
基金the financial support from the National Key R&D Program of China (2017YFD0502005)the support of the Faculty of Veterinary and Agricultural Sciences Start-up Fund, The University of Melbourne, Australia
文摘This experiment was conducted to investigate the effects of live yeast and yeast cell wall polysaccharides on growth performance,rumen function and plasma lipopolysaccharides(LPS) content and immunity parameters of beef cattle.Forty Qinchuan cattle were randomly assigned to one of four treatments with 10 replicates in each treatment.The dietary treatments were: control diet(CTR),CTR supplemented with 1 g live yeast(2×10^10 live cell g^-1 per cattle per day(YST1),CTR supplemented with 2 g live yeast per cattle per day(YST2) and CTR supplemented with 20 g of yeast cell wall polysaccharides(30.0%≤β-glucan≤35.0%,and 28.0%≤mannanoligosaccharide≤32.0%) per cattle per day(YCW).The average daily gain was higher(P=0.023) and feed conversion ratio was lower(P=0.042) for the YST2 than the CTR.The digestibility of neutral detergent fiber(P=0.039) and acid detergent fiber(P=0.016) were higher in yeast supplemented groups.The acetic acid:propionic acid of the YST2 was lower compared with the CTR(P=0.033).Plasma LPS(P=0.032),acute phase protein haptoglobin(P=0.033),plasma amyloid A(P=0.015) and histamine(P=0.038) were lower in the YST2 compared with the CTR.The copies of fibrolytic microbial populations such as Fibrobacter succinogenes S85,Ruminococcus albus 7 and Ruminococcus flavefaciens FD-1 of the YST2 were higher(P<0.001),while the copies of typical lactate producing bacteria Streptococcus bovis JB1 was lower(P<0.001) compared with the CTR.Little differences were observed between the CTR,YST1 and YCW in growth performance,ruminal fermentation characteristics,microbial populations,immunity indices and total tract nutrient digestibility.It is concluded that the YST2 could promote fibrolytic microbial populations,decrease starch-utilizing bacteria,reduce LPS production in the rumen and LPS absorption into plasma and decrease inflammatory parameters,which can lead to an improvement in growth performance in beef cattle.
文摘A common problem in rabbit production is the occurrence of digestive disorders just after weaning, and fiber is well known to be bcncficiai for rabbit gastrointestinal health. In order to test the hypothesis that whether the good points of fiber increases with its dietary content, three isoenergetic and isonitrogenous diets and ninety mixed-sex New Zealand rabbits weaned 35-d-old were used. The results can be concluded as following： （1） Average daily feed intake （ADFI） tended to increase （i〉=0.058） while average daily gain （ADG） （p=0.001） and feed conversion ratio （FCR） （p〈0.001） deteriorated with increasing dietary ADF content. The highest morbidity was observed in the rabbits fed the highest dietary ADF concentration. （2）A decreasing coefficient of total tract apparent digestibility （CTTAD） of dry matter （DM） and crude protein （CP） was obtained with the increase of dietary fiber level （p〈0.001 and =0.003）. （3） A significant negative effect of treatments on sucrase and maltase activities in the jejunum was observed （p=0.001 and 0.003）. （4） The volatile fatty acid （VFA） concentration （p=0.011） and butyric acid （% total VFA） （P=0.001） dropped while the NH3-N concentration （P〈0.001）, pH （P=0.004） and acetic acid （% total VFA） （P〈0.001） increased with increasing dietary ADF. It was concluded that high fiber level was unfavorable to the rabbits in the first two weeks after weaning.
