Search

In pastoral areas and semi-agricultural and semi-pastoral areas of Sichuan, beef cattle breeding mode is mainly dependent on nature to raise livestock. On the one hand, owing to the shortage of forage grass in spring, cows suffer from malnutrition. On the other hand, competition for milk between human and livestock further deepens the malnutrition of newborn calves, and the mortality rate even exceeds 40%, resulting in serious waste of beef cattle source resources. The objective of this study was to investigate the effect of different cultivation methods (calves with and without dam) and age on calves hindgut microbiome. Sixteen healthy calves (Yak ♂ × Pian cattle ♀, with similar birthday 0 ± 2 d and body weight 13.1 ± 1.13 kg), were selected and randomly divided into two groups. The control group was cultivated with heifers, whereas the treatment group was cultivated without heifers and was fed milk replacer during the whole 95 days formal experimental period. Fecal samples were collected on 35, 65 and 95 days of age for high-throughput sequencing. The α-diversity was different between the two groups on day 35; however, the bacterial species richness and diversity was almost not different on day 95. Principal coordinates analysis revealed significant difference between the two groups on all the three time points, and the timepoints of day 65 and 95 were closer and separated from the timepoints of day 35 in calves with dam, whereas the timepoints of day 35 and 65 were closer and separated from day 95 in calves without dam. As time passed, the abundance of Firmicutes increased, while Proteobacteria and Actinobacteria decreased in calves with dam. But in calves without dam, the abundance of Bacteroidetes and Proteobacteria increased on day 65 and then decreased on day 95. In genus level, the relative abundance of Bacteroides decreased in calf with dam while its abundance increased first and then decreased in calf without dam but both resulted in the range of 3.5~4.5%. The relative abundance of Lactobacillus decreased, whereas Ruminococcaceae UCG-005 increased in both groups as the calf grew up. It was concluded that the richness and evenness of the microbial communities was higher in calves with dam than without dam, and a stable gut microbiome in calve with dam is established earlier than calf without dam.

Agricultural soils contaminated with heavy metals poison crops and disturb the normal functioning of rhizosphere microbial communities. Different crops and rhizosphere microbial communities exhibit different heavy metal resistance mechanisms. Here, indoor pot studies were used to assess the mechanisms of grain and soil rhizosphere microbial communities on chromium (Cr) stress. Millet grain variety 'Jingu 21' (Setaria italica) and soil samples were collected prior to control (CK), 6 hours after (Cr_6h), and 6 days following (Cr_6d) Cr stress. Transcriptomic analysis, high-throughput sequencing and quantitative polymerase chain reaction (qPCR) were used for sample determination and data analysis. Cr stress inhibited the expression of genes related to cell division, and photosynthesis in grain plants while stimulating the expression of genes related to DNA replication and repair, in addition to plant defense systems resist Cr stress. In response to chromium stress, rhizosphere soil bacterial and fungal community compositions and diversity changed significantly (p < 0.05). Both bacterial and fungal co-occurrence networks primarily comprised positively correlated edges that would serve to increase community stability. However, bacterial community networks were larger than fungal community networks and were more tightly connected and less modular than fungal networks. The abundances of C/N functional genes exhibited increasing trends with increased Cr exposure. Overall, these results suggest that Cr stress primarily prevented cereal seedlings from completing photosynthesis, cell division, and proliferation while simultaneously triggering plant defense mechanisms to resist the toxic effects of Cr. Soil bacterial and fungal populations exhibited diverse response traits, community-assembly mechanisms, and increased expression of functional genes related to carbon and nitrogen cycling, all of which are likely related to microbial survival during Cr stress. This study provides new insights into resistance mechanisms, microbial community structures, and mechanisms of C/N functional genes responses in cereal plants to heavy metal contaminated agricultural soils. Portions of this text were previously published as part of a preprint (https://www.researchsquare.com/article/rs-2891904/v1). [ABSTRACT FROM AUTHOR]

Background Yak (Bos grunniens) is an ancient bovine species on the Qinghai-Tibetan Plateau. Due to extremely harsh condition in the plateau, the growth retardation of yaks commonly exist, which can reduce the incomes of herdsman. The gastrointestinal barrier function plays a vital role in the absorption of nutrients and healthy growth. Functional deficiencies of the gastrointestinal barrier may be one of the contributors for yaks with growth retardation. Methods To this end, we compared the growth performance and gastrointestinal barrier function of growth-retarded (GRY) and normal yaks (GNY) based on average daily gain (ADG), serum parameters, tissue slice, real-time PCR, and western blotting, with eight yaks in each group. Results GRY exhibited lower (P

This work was aimed to investigate the effects of the different particle size of ground alfalfa hay on caecal microbial and archeal communities of rabbits. One hundred-twenty New Zealand rabbits (950.3 ± 8.82 g) were allocated into four treatments, with five replicates in each treatment and six rabbits in each replicate. The particle sizes of the alfalfa meal in the four treatment diets were 2,500, 1,000, 100 and 10 µm respectively, while the other ingredients were ground through a 2.5 mm sieve. High-throughput sequencing technology was applied to examine the differences in bacteria and methanogenic archaea diversity in the caecum of the four treatment groups of rabbits. A total of 745,946 bacterial sequences (a mean of 31,081 ± 13,901 sequences per sample) and 539,227 archaeal sequences (a mean of 22,468 ± 2,443 sequences per sample) were recovered from twenty-four caecal samples, and were clustered into 9,953 and 2,246 OTUs respectively. A total of 26 bacterial phyla with 465 genera and three archaeal phyla with 10 genera were identified after taxonomic summarization. Bioinformatic analyses illustrated that Firmicutes (58.69% ∼ 68.50%) and Bacteroidetes (23.96% ∼ 36.05%) were the two most predominant bacterial phyla and Euryarchaeota (over 99.9%) was the most predominant archaeal phyla in the caecum of all rabbits. At genus level, as the particle size of alfalfa decreased from 2,500 to 10 µm, the relative abundances of Ruminococcaceae UCG-014 (P