Effects of Early Weaning on the Rumen Bacterial Diversity in Dairy Lambs

BackgroundThe early weaning (EW) technology is an efficient method to improve the economic value of dairy ewes and satisfy the nutritional requirement of lambs which due to multiple fetuses or insufficient milk production of ewes. However, the affection of EW for rumen microflora is needed to evaluation because of the rumen microflora at early life would affect the health of host at whole life. In this study, the rumen microflora of dairy sheep with different EW time (D7, D15 and D25) were analyzed through 16s rDNA sequencing at D90. ResultsThe results showed that the application of EW did not affect the development of rumen. The species richness of the EW25 group was higher than EW7 and EW15 groups, while there was no significant difference in the abundance of microbial species between the CON and EW groups. At the phylum level, Firmicutes, Bacteroidetes, Fibrobacteres, Spirochaetes, Proteobacteria and Actinobacteria were the most dominant phyla in all the samples. At tenricutes level, the relative abundance of EW7 group was significantly higher than other three groups (p<0.05). The spearman correlation coefficient analysis showed that pH was positively correlated with Rikenellaceae_RC9, Succiniclasticum, F082_unclassified, etc. (p<0.05), and negatively correlated with Ruminococcaceae_UCG-014, Succiniclasticum, Selenomonas, etc. (p<0.05). The content of MCP was positively correlated with CAG-352 and Ruminococcus_2 (p<0.05). The width of rumen papilla was negatively correlated with non-classifiable bacteria (p<0.05). The thickness of rumen muscle layer was positively correlated with Sharpea (p<0.05). ConclusionsIn summary, the EW of dairy lambs does not affect the development of rumen at early life. The rumen bacterial diversity showed some differences between different EW days of age but no obvious effect, which could be a reference for dairy lamb’s EW time selection.

Effects of Oat Hay Content in Diets on Nutrient Metabolism and the Rumen Microflora in Sheep

Oats have the characteristics of drought tolerance, cold resistance, strong adaptability, high forage yield, and high nutritional value. However, there are few reports on the most appropriate amount of oat hay in ruminant diets, the digestion and metabolism of ruminants, and the rumen microflora. To study the effects of oat hay content in diets on nutrient digestion and metabolism and the rumen microflora in sheep, 9 German Merino and Mongolian crossbred rams of similar body condition and weight with permanent fistulas were selected. The 3 × 3 Latin square design was used to randomly divide the rams into 3 groups, with 3 animals in each group. The three groups were fed different kinds of roughage: whole-plant corn silage only (corn silage group, CSG), oat hay mixed with whole-plant corn silage (1:1) (mixed group, MG), and oat hay only (oat hay group, OHG). The nutrient digestion and metabolism of each group were measured, and the pH and rumen microflora were examined after feeding for different durations. Dynamic changes in microbial communities were detected. The nutrient digestion and metabolism results showed that, with an increase in the content of oat hay in the diet, the intake and apparent digestibility of dry matter (DM) and organic matter (OM) showed an increasing trend, and the intake, digestion, and stability of acid detergent fiber (ADF) and neutral detergent fiber (NDF) increased in the OHG. The apparent digestibility, dietary nitrogen, deposited nitrogen, and nitrogen retention rate in this group were significantly higher than those in the CSG (p < 0.05). The rumen pH and sequencing results showed that the rumen fluid pH of the CSG was significantly lower than that of the OHG at 1 and 5 h (p < 0.05). The main microbial in the rumen of the three groups of sheep were Bacteroides, Sclerotium, and Proteus. The dominant taxon in the CSG was Prevotella, followed by Vibrio syringae, and the dominant taxon in the MG and OHG was Prevotella, followed by Rikenellaceae. Redundancy analysis showed that ADF and NDF in the feed had an effect on the abundance of Fibrobacteres, Ruminococcaceae, and Prevotella. Our findings indicate that the use of oat hay roughage in the diet significantly improves the apparent digestibility of NDF and ADF and helps maintain the stable state of the sheep’s rumen internal environment and the growth of rumen microorganisms.

Effect of Sterilized Rumen Fluid Supplementation Ways in Lactation Period on Rumen Microflora of Calves after Weaning

Background: The presence of the rumen makes the ruminant special, and the rumen flora has an important influence on the ruminant. The rumen is not fully developed in young ruminants. The purpose of this study was to investigate the effects of supplemental feeding of rumen fluid from high-yielding dairy cows with suckling calves on rumen microflora after weaning. For the experiment, 12 newborn Holstein male calves with the same feeding environment and similar ages were selected. They were randomly divided into 3 groups, with 4 in each group. The three treatments were: addition of sterilized rumen fluid to milk (Group M), addition of sterilized rumen fluid to starter feed (Group S), and a normal fed control group (Group C). The growth performance indices and blood indices were measured, and rumen fluid samples were collected after weaning. Furthermore, 16S rDNA sequencing and LC-MS metabolome detection were performed.Results: Compared with the control group, the growth performance of group S was significantly increased, and the difference between group M and group C was not significant. For the immune indicators in the blood, group M showed a greater difference from group C; the blood-related and energy-related indicators were less different between the two test groups and the control group. For the rumen fluid microbiome and metabolome detection, both groups M and S showed significant differences from group C.Conclusions: The microflora and metabolites were different due to different supplementary feeding methods. Metabolites with differential levels were mainly involved in metabolic pathways such as amino acid metabolism, nucleotide metabolism, and carbohydrate metabolism.