# Effects of Stevia Straw Supplementation on Meat Quality, Nutrient Composition, and Rumen Microbiota in Sheep

## TL;DR

Adding stevia straw to sheep feed improves meat quality and nutrient content without harming their gut microbes.

## Contribution

This study shows that 15–25% stevia straw in sheep diets enhances meat quality and rumen microbiota.

## Key findings

- Adding 15% and 25% stevia straw increased pre-slaughter body weight in sheep.
- Stevia straw improved fatty acid profiles, increasing unsaturated fatty acids in meat.
- Stevia straw had no negative effect on rumen microflora and may enhance its activity at 15%.

## Abstract

Stevia (Stevia rebaudiana), commonly referred to as sweet grass or honey leaf, is an annual herbaceous plant of the Stevia genus in the Compositae family. Stevia straw, composed of stems and roots remaining after leaf harvesting, is highly nutritious and rich in various bioactive compounds. It has been shown to regulate livestock production performance, improve the quality of animal products, and enhance economic benefits in animal farming. This study demonstrates that dietary supplementation of 15–25% stevia straw to the ration can significantly improve the slaughtering performance, meat quality and muscle nutrient composition of fattening sheep. In addition, the addition of stevia straw had no negative effect on the rumen microflora, and the 15% level could increase the abundance and activity of the rumen microflora, so it is recommended to use 15% stevia straw in the ration for sheep during the fattening period.

This study investigated the effects of dietary stevia straw supplementation on meat quality, amino acid and fatty acid content, and rumen microbial diversity in sheep. A total of 50 ram lambs (3–4 months, 27.01 ± 3.8 kg) were randomly assigned to five groups. Each group received a total mixed ration supplemented with 0% (control), 5%, 15%, 25% and 35% dry stevia straw for 72 days. Adding 15% and 25% stevia straw significantly increased the pre-slaughter body weight. EE content was also significantly higher across all experimental groups (p < 0.01), showing a linear increase with supplementation. Glutamic acid content in the 15% group was significantly higher than that in the 25% group (p < 0.05). The addition of stevia straw improved the fatty acid profile: C18:1n9c content in the 5%, 15%, and 25% groups was significantly higher than that in the CK (Control) group (p < 0.05); C18:2n6c content in the 25% group was significantly higher than that in the CK, 5%, and 15% groups (p < 0.05); the content of (C20:1) was extremely significantly higher in all experimental groups compared to the CK group. Additionally, the unsaturated fatty acid content in the 25% group was significantly higher than that in the CK group (p < 0.05). The relative abundances of Bacteroidota and Firmicutes were increased in the 25% and 35% groups, but the differences were not significant (p > 0.05). In conclusion, dietary supplementation of 15–25% stevia straw to the ration can significantly improve the slaughtering performance, meat quality and muscle nutrient composition of fattening sheep. In addition, the addition of stevia straw had no negative effect on the rumen microflora, and the 15% level could increase the abundance and activity of the rumen microflora, so it is recommended to use 15% stevia straw in the ration for sheep during the fattening period.