Paternal weight of ducks may have an influence on offspring' small intestinal function and cecal microorganisms

Fermented Astragalus membranaceus could promote the liver and intestinal health of juvenile tiger grouper (Epinephelus fuscoguttatus)

In order to understand the effects of fermented Astragalus membranaceus (FAM) on the liver and intestinal health of tiger grouper (Epinephelus fuscoguttatus), this study was conducted. This study evaluates the effects of different levels of FAM on liver and intestinal tissue structure, serum biochemical parameters, intestinal digestive enzyme, and microbiota structure of tiger grouper. Fish were fed with diets (crude protein ≥ 48.0%, crude fat ≥ 10.0%) with five levels of FAM (L1:0.25%, L2: 0.5%, L3: 1%, L4: 2% and L5: 4%) in the experimental groups and a regular diet was used as the control (L0: 0%) for 8 weeks. Compared with AM, the protein content of FAM was significantly changed by 34.70%, indicating that a large amount of bacterial protein was produced after AM fermentation, and its nutritional value was improved. FAM had significant effects on the growth performance of tiger grouper (p < 0.05). The high-density lipoprotein cholesterol (HDL-C) was highest in L4 group, being significantly different from L0 group. The area and diameter of hepatocytes were lowest in L3 and L4, and the density of hepatocyte was highest in L4 group and relatively decreased in L5 group. The mucosal height and muscular thickness were highest in L3 group. The intestinal microbiota structure of tiger grouper was changed under the intervention of FAM. The lower abundance of potential pathogenic bacteria and higher abundance of probiotics colonization in the L4 group showed that the dose of FAM had the best effect on improving the health of intestinal microbiota. This study indicates that the addition of FAM in the feed contributes to liver health, improves intestinal morphology, and regulates the intestinal microbiota of tiger grouper. The addition ratio of 1%-2% is better for intestinal and liver health, and a high addition ratio will cause liver damage. Our work will provide a reference for the addition and management of FAM in the aquaculture industry.

Effects of floor- and net-rearing systems on intestinal growth and microbial diversity in the ceca of ducks

BACKGROUND

Rearing systems can affect livestock production directly, but whether they have effects on intestinal growth states and ceca microorganisms in ducks is largely unclear. The current study used Nonghua ducks to estimate the effects of rearing systems on the intestines by evaluating differences in intestinal growth indices and cecal microorganisms between ducks in the floor-rearing system (FRS) and net-rearing system (NRS).

RESULTS

The values of relative weight (RW), relative length (RL) and RW/RL of the duodenum, jejunum, ileum and ceca in the FRS were significantly higher than those in the NRS during weeks 4, 8 and 13 (p < 0.05). A total of 157 genera were identified from ducks under the two systems, and the dominant microorganisms in both treatments were Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria at the phylum level. The distribution of microorganisms in the ceca of the two treatments showed significant separation during the three time periods, and the value of the Simpson index in the FRS was significantly higher than that in the NRS at 13 weeks (p < 0.05). Five differential microorganisms and 25 differential metabolic pathways were found in the ceca at week 4, seven differential microorganisms and 25 differential metabolic pathways were found in the ceca at week 8, and four differential microorganisms and two differential metabolic pathways were found in the ceca at week 13.

CONCLUSIONS

The rearing system influences duck intestinal development and microorganisms. The FRS group had higher intestinal RL, RW and RW/RL and obviously separated ceca microorganisms compared to those of the NRS group. The differential metabolic pathways of cecal microorganisms decreased with increasing age, and the abundance of translation pathways was higher in the NRS group at week 13, while cofactor and vitamin metabolism were more abundant in the FRS group.

The differences in intestinal growth and microorganisms between male and female ducks

There are great differences in physiological and biological functions between animals of different sexes. However, whether there is a consensus between sexes in duck intestinal development and microorganisms is still unknown. The current study used Nonghua ducks to estimate the effect of sex on the intestine by evaluating differences in intestinal growth indexes and microorganisms. The intestines of male and female ducks were sampled at 2, 5, and 10 wk from the duodenum, jejunum, ileum, and cecum. Then, the intestinal length and weight were measured, the morphology was observed with HE staining, and the intestinal content was analyzed by 16S rRNA sequencing. The results showed that male ducks have shorter intestinal lengths with higher relative weights/relative lengths. The values of jejunal villus height (VH)/crypt depth (CD) of female ducks were significantly higher at 2 wk, whereas the jejunal VH/CD was significantly lower at 10 wk. There was obvious separation of microorganisms in each intestinal segment of ducks of different sexes at the 3 time periods. The dominant phyla at different stages were Firmicutea, Proteobacteria, Bacteroidetes, and Actinobacteria. The duodenal Chao index at the genus level of male ducks was significantly higher at 10 wk than that of female ducks. Significantly different genera were found only in the jejunum, and the abundances of Escherichia_Shigella, Pseudomonas, Clostridium_sensu_stricto_1, Sphingomonas, and Desulfovibrio in male ducks were higher than those in female ducks, whereas the abundance of Rothia was lower, and the abundance of viral infectious diseases, lipid metabolism, metabolism of terpenoids and polyketides, parasitic infectious diseases, xenobiotic biodegradation and metabolism, cardiovascular disease, and metabolism of other amino acids in male ducks were higher than that in female ducks, whereas gene folding, sorting and degradation pathways, and nucleotide metabolism were lower. This study provides a basic reference for the intestinal development and microbial symbiosis of ducks of different sexes.