Comfrey (Symphytum spp.) as an alternative field crop contributing to closed agricultural cycles in chicken feeding

Pectin from comfrey roots alleviate DSS-induced ulcerative colitis in mice through modulating the intestinal barrier

The objective of this study was to investigate whether pectin extracted from comfrey roots (CRPs) could alleviate ulcerative colitis (UC) induced by sodium dextran sulfate (DSS) in mice by improving the intestinal barrier. CRP was able to relieve symptoms associated with weight loss, diarrhea, and colon length in UC mice. CRP inhibited the excessive secretion of TNF-α and IL-6 and increased the level of IL-10 in the serum. After CRP treatment, the mRNA expression levels of ZO-1 and Muc2 increased. The colonic epithelial cells recovered well, and the mucous layer was relatively intact in the CRP group. CRP and 5-aminosalicylic acid (ASA) alleviated UC symptoms in mice by reducing the abundance of Oscillibacter, Alistipes, and Anaeroplasma and increasing the abundance of Lachnospiraceae_UCG-001 to regulate the intestinal microflora. The abundance of Rikenellaceae was positively correlated with the mRNA expression level of ZO-1, and the abundance of Monoglobus was positively correlated with the mRNA expression level of Muc2. These results suggested that CRP could repair the intestinal barrier and mitigate DSS-induced colon damage in mice, indicating that CRP may be a potential functional component in combating UC.

Comfrey polysaccharides modulate the gut microbiota and its metabolites SCFAs and affect the production performance of laying hens

Effects of dietary supplementation of comfrey polysaccharides (CPs) on production performance, egg quality, and microbial composition of cecum in laying hens were evaluated. A total of 240 laying hens were allocated into 4 groups with 6 replicates per group. The laying hens were fed diets containing CPs at levels of 0, 0.5, 1.0, and 1.5 %, respectively. The results showed that the egg production rate increased by 5.97 %, the egg mass improved by 6.71 %, and the feed conversion rate reduced by 5.43 % in the 1.0 % supplementation group of CPs compared with those in the control group. The digestibility of ash, crude fat, and phosphorus was notably improved by the addition of CPs at 1.0 % (P < 0.05). The relative abundances of Bacteroidetes at the phylum level, Bacteroidaceae, Rikenellaceae, and Prevotellaceae at the family level were increased by CPs (P < 0.05). The relative abundances of Bacteroides, Megamonas, Rikenellaceae_RC9_gut_group, [Ruminococcus]_torques_group, Methanobrevibacter, Desulfovibrio, Romboutsia, Alistipes, and Intestinimonas at the genus level were increased by CPs (P < 0.05). Dietary supplementation of CPs could enhance the production performance of laying hens, which might be related to the improvement of nutrient digestibility and microbial community modulations in the cecum. Therefore, CPs have potential application value as prebiotics in laying hens.

Comfrey (Symphytum spp.) as a feed supplement in pig nutrition contributes to regional resource cycles

In smallholder agriculture, the fast-growing and perennial accumulator plant comfrey (Symphytum spp.) was used to supply pigs with protein and minerals. Comfrey leaves show similar values in dry matter as soybean or blue lupine in crude protein content, but much higher levels of calcium and phosphorus. However, in terms of increased efficiency in animal husbandry, comfrey has been displaced by mainly soybean and cereals. Due to its profile of macro- and micronutrients the use of comfrey could have the potential to re-establish local resource cycles and help remediate over-fertilized soils. The aim of the study was to evaluate whether a modern pig breed accepts a continuous feed supplement of dried comfrey leaves. After an initial adaptation period post-weaning, German Landrace piglets were subjected to either a standard control diet or a diet supplemented with 15% dried comfrey leaves for 4 weeks. Body weight was reduced in comfrey-supplemented piglets compared to controls, which might be attributed to reduced palatability in the experimental setting. Nevertheless, comfrey-supplemented piglets exhibited adequate bone mineralization and intestinal integrity. The microbiome profile in feces and digesta revealed higher diversity in comfrey-supplemented piglets compared to controls, with pronounced effects on the abundances of Treponema and Prevotella. This may be due to described bio-positive components of the comfrey plant, as data suggest that the use of comfrey leaves may promote intestinal health. Digestive tract phosphorus levels were reduced in piglets receiving comfrey supplementation, which may ultimately affect phosphorus levels in manure. Results indicate that comfrey leaves could serve as a feed component in integrated agricultural systems to establish regional nutrient cycles. The trial provides a basis for further work on comfrey as a regionally grown protein source and effective replacement for rock mineral supplements.