# Differences in rectal fecal microbes among Hu sheep, Tibetan sheep, and their hybrid breeds and their relationship with growth traits

## TL;DR

This study compares gut microbes in different sheep breeds and hybrids, finding that genetics influence microbial differences linked to growth traits.

## Contribution

The study identifies breed-specific microbial biomarkers and suggests their role in growth traits via lipid metabolism.

## Key findings

- Significant microbial differences were found among Hu sheep, Tibetan sheep, and their hybrids.
- Six microbial biomarkers were identified in each parent breed, potentially affecting growth through lipid metabolism.
- Hybrid sheep inherited gut microbes from their parents to varying degrees.

## Abstract

Variety and diversity serve as the foundation for animal husbandry development. Nowadays, heterosis is often used to improve animal performance and increase economic benefits. The intestine is an important organ for nutrient absorption and is also the largest immune organ in the body. Intestinal microorganisms can be influenced by various factors such as animal growth and development stages, gender, health status, feed nutrition level, and host genetic background, among others. In this study, three strains of male sheep, with no significant differences in initial weight at 6 months old, were raised under the same conditions until they reached 9 months of age. We collected the rectal feces of these 9-month-old sheep and compared the differences in rectal fecal microorganisms among the three strains using 16S rDNA sequencing technology. The permutational multivariate analysis of variance test revealed significant differences in microorganisms among different strains. Additionally, we identified six biomarkers in Tibetan sheep and Hu sheep, respectively. Functional enrichment analysis showed that microorganisms may affect the growth traits of sheep through lipid metabolism, and the functional differences among different strains were obvious. Therefore, we believe that crossbreeding can result in the offspring obtaining intestinal microorganisms from their parents to varying degrees, and host heredity is the primary cause of the intestinal microorganism differences.

In this study, we identified parental biomarkers by exploring the relationship between parental and hybrid offspring and concluded that these biomarkers may affect related growth traits through fat deposition or lipid metabolism pathways. We also found that hybrid sheep inherited rectal fecal microbes from their parents to varying degrees.