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This study was conducted to test the hypothesis that low‐tannin sorghum grain produced in China as a potential substitute for corn in diets could not impair the performance of nursery pigs. A total of 60 pigs (7.2 ± 1.2 kg) were randomly assigned to 2 diets with 5 replicate pens per treatment. Corn‐based diet (CBD) included 60% corn grain during the overall experimental period, and sorghum‐based diet (SBD) consisted of 30% (d 1 to 14) or 60.55% (d 15 to 28) sorghum grain in partial or total replacement of corn grain. Both diets were formulated to contain the same amount of digestible energy and indispensable amino acids. The results demonstrated no differences in growth performance or apparent digestibility of gross energy between treatments over the whole period. However, the substitution of corn by sorghum reduced (p < 0.05) or tended to reduce (p = 0.09) apparent digestibility of crude protein associated with an increased faecal nitrogen excretion per weight gain (p < 0.05). Pigs fed SBD had higher contents of urea nitrogen, total triglyceride and insulin in serum than those fed CBD (p < 0.05). Visceral organ weights or antioxidant enzyme activities in serum or liver were not different between treatments. Compared with CBD, SBD increased or tended to increase amylase activity in jejunal mucosa (p < 0.05) or trypsin activity in duodenal mucosa (p = 0.08). Replacement of corn by the low‐tannin sorghum in diets did not influence the microbiota community based on alpha and beta diversity in caecal and colonal digesta. Overall, the home‐grown low‐tannin sorghum could be an alternative energy source in diets for pigs without adverse effects on growth performance. [ABSTRACT FROM AUTHOR]

Summary: Recent emergence of mcr‐1‐positive Escherichia coli (MCRPEC) is causing serious concern around the world. Due to poultry‐origin E. coli holding zoonotic potential, the improved understandings of MCRPEC population structure and antimicrobial resistance are critical to public health purposes. This study provided novel insights into the molecular epidemiology of avian‐origin MCRPEC. For the mcr genes prevalence study, we analysed 1,360 E. coli recovered from avian colibacillosis in eastern China from 2015 to 2017. The mcr‐1 was present in 172 (12.6%) E. coli isolates. For all of MCRPEC isolates, MICs of colistin were ≥4 mg/L. Avian‐origin MCRPEC was widely distributed throughout phylogroups A, B1, B2, D, and F. Moreover, those isolates were assigned to 52 unique STs, such as ST48, ST117, ST131, and ST648, suggesting substantial horizontal dissemination of mcr‐1 gene through avian‐origin E. coli populations. The susceptibility of MCRPEC isolates was tested with 26 antimicrobial agents from 16 antimicrobial categories. There were high resistance rates of MCRPEC isolates against the clinically used antibiotics. All MCRPEC isolates in this study presented the multidrug‐resistant (MDR) trait were even considered as extensively drug‐resistant (XDR) strains. Resistance genotypes and plasmid replicon profiling showed that a majority of MCRPEC isolates contained plasmid‐mediated resistance genes and exhibited the co‐existence of mcr‐1 with ESBLs and pAmpCs genes. Furthermore, the overlapped distribution of ST types and resistance gene contents was detected among MCRPEC isolates from humans and poultry. Besides mcr‐1, our findings highlighted a significant prevalence of plasmid‐mediated resistance genes among avian‐origin MCRPEC isolates. [ABSTRACT FROM AUTHOR]

Simple Summary: In China, a shortage of protein resources is an important limiting factor to the economic benefit of pig production, and the use of protein-restriction diets balanced with amino acids is an effective strategy to save protein resources. However, long-term protein-restriction diets can impair the growth performance, and the reason is still unknown. This study is to investigate the response of gastrointestinal physiology and gut microbiota to the condition of long-term low-protein diet and to try to provide a theoretical foundation for better use of protein resources in swine production. Results showed that presented with moderate protein-restriction diets, pigs are able to adjust their absorption and consumption of nutrients to maintain growth performance; whereas extremely low-protein diets suppress pigs' appetite, impair intestinal morphology, decrease Lactobacillus and Streptococcus, and reduce energy expenditure. Thus, moderate reduction of dietary protein is more suitable for pig production than extremely low-protein diets supplemented with essential amino acids, and moderate protein-restriction diets can potentially increase protein utilization in pig production. Using protein-restriction diets becomes a potential strategy to save the dietary protein resources. However, the mechanism of low-protein diets influencing pigs' growth performance is still controversial. This study aimed to investigate the effect of protein-restriction diets on gastrointestinal physiology and gut microbiota in pigs. Eighteen weaned piglets were randomly allocated to three groups with different dietary protein levels. After a 16-week trial, the results showed that feeding a low-protein diet to pigs impaired the epithelial morphology of duodenum and jejunum (p < 0.05) and reduced the concentration of many plasma hormones (p < 0.05), such as ghrelin, somatostatin, glucose-dependent insulin-tropic polypeptide, leptin, and gastrin. The relative abundance of Streptococcus and Lactobacillus in colon and microbiota metabolites was also decreased by extreme protein-restriction diets (p < 0.05). These findings suggested that long-term ingestion of a protein-restricted diet could impair intestinal morphology, suppress gut hormone secretion, and change the microbial community and fermentation metabolites in pigs, while the moderately low-protein diet had a minimal effect on gut function and did not impair growth performance. [ABSTRACT FROM AUTHOR]

• Majority of avian-source MCRPEC isolates were classified as ExPECs. • The potential transmission of avian-source mcr-1 -positive ExPEC to humans. • The zoonotic risk of MCRPEC appeared to be close association with ColV/ColBM type virulence plasmids. • Avian-origin MCRPEC, especially high-risk clones, could be recognized as a foodborne pathogen. Colisepticemia caused by bloodstream infection of the extraintestinal pathogenic Escherichia coli (ExPEC) has become a serious public health problem. The recent emergence of the colistin-resistant Enterobacteriaceae , especially mcr-1 -positive E. coli (MCRPEC) exerts great concern around the world. The molecular epidemiology and zoonosis risk of avian-origin MCRPEC are reported to be substantially lower. Here, we presented a system-wide analysis of emerging trends and zoonotic risk of MCRPEC recovered from avian colibacillosis in China. Our results showed the majority of avian-source MCRPEC isolates were classified as ExPECs. We also found that not only MCRPEC in phylogroups B2 and D, but also several E. coli populations in groups B1 and F possessed high virulence in the two models of avian colibacillosis and three rodent models for ExPEC-associated human infections. The high-virulent MCRPEC clones belong to ST131, as well as ST-types (such as ST48, ST117, ST162, ST501, ST648, and ST2085). Our data suggested the zoonotic risk of MCRPEC appeared to be a close association with ColV/ColBM type virulence plasmids. A comprehensive genomic analysis showed the overlapped of ColV/ColBM plasmids contents between MCRPEC isolates from humans and poultry. Identification of ColV/ColBM plasmids among human MCRPEC isolates revealed the potential transmission of avian-source mcr-1 -positive ExPECs to humans. Moreover, the presence of ColV/ColBM plasmid-encoded virulence determinants, could be used as a predictive label for pathogenic MCRPEC. These findings highlighted avian-origin MCRPEC isolates could be recognized as a foodborne pathogen. [ABSTRACT FROM AUTHOR]

Background: Four cannulated primiparous Holstein dairy cows (84 ± 25 DIM) were used in a 2 × 2 crossover experimental design. The two diets contained 40% (low-concentrate diet, or control diet, LC) and 70% (high-concentrate diet, or SARA induction diet, HC) concentrate feeds respectively. Milk samples were collected on days 17, 18 and 19 of each experimental period. DNA was extracted from each milk sample, and pyrosequencing was applied to analyse the milk microbial community., Results: Regardless of diet, the bacterial community of milk was dominated by Actinobacteria, Firmicutes, Proteobacteria and Bacteroidetes. HC feeding showed a higher proportion of some mastitis-causing pathogen bacteria, such as Stenotrophomonas maltophilia, Streptococcus parauberis and Brevundimonas diminuta, as well as of psychrotrophic bacteria, such as Pseudomonas, Brevundimonas, Sphingobacterium, Alcaligenes, Enterobacter and Lactobacillus. However, the diversity of the milk bacterial microbiota (ACE, Chao, and Shannon index) was not affected by HC feeding., Conclusion: To the best of our knowledge, this is the first report on the use of pyrosequencing for evaluating the impacts of nutrition on changes in the composition of milk microbiota. These findings indicate that HC feeding may increase the risk of dairy cows suffering from mastitis, decrease the organoleptic quality of raw milk and dairy products, and limit the shelf life of processed fluid milk., (© 2014 Society of Chemical Industry.)

Molecular diversities of rumen archaea of Jinnan (South Shanxi Province, China) cattle was analyzed and compared by 16S rRNA gene sequencing from three clone libraries generated using three different archaea-specific primer sets, respectively. DNA from rumen of 4 Jinnan cattle was extracted, and methanogen 16S rRNA gene was amplified using archaea-specific primer sets. Three clone libraries were generated by using vector pGEM-T and cloning into E.coli JM109. One hundred clones were randomly picked up for each library and RFLP was analyzed for each clone to obtain OTUs. Sequences from each OTU were analyzed and compared with available sequences in GenBank. The first library, generated with primers Arch f364/1386, produced four groups of sequences, affiliated with 4 Methanobrevibacter strains, 1Y (61% of clones), SM9 (23% of clones), NT7 (14% of clones), and AK-87(2% of clones). The second library, generated with primers 1 Af/1100Ar, two groups of sequences, one affiliated with Methanobacterium aarhusense (72% of clones) and the other with Methanosphaera stadtmanae DSM 3091 (28% of clones). The third library, generated with primers Met86F/Met1340R, produced a high degree of diversity. It included the sequence groups found in the first and the second libraries, as well as sequences affiliated with the Methanomicrobium mobile (2% of clones) and uncultured euryarchaeote sequences (7% of clones). The phylogenetic analysis indicated that archaea found in the three libraries were clustered in Methanobrevibacter, Methanobacterium, Methanosphaera, Methanomicrobium, and unidentified euryarchaeote of the Euryarcharota. There were 25 unidentified sequences belonged to Euryarchaeota. This suggests the existence of novel methanogens in the rumen of Jinnan cattle.