# Comparative Analysis of Fecal Microbiota and Metabolomic Profiles in Male and Female Leizhou Goats Offered a 10% Crude Protein Diet Among Four Energy Levels

## TL;DR

This study compares gut microbiota and metabolism in male and female goats on a low-protein diet with varying energy levels, revealing gender-specific differences that could help in designing better feeding strategies.

## Contribution

The study identifies gender-specific differences in gut microbiota and metabolism in goats under a low-protein diet with varying energy levels.

## Key findings

- Female and male goats showed distinct gut microbiota compositions, with different dominant genera.
- There were significant differences in the relative abundance of several bacterial genera between genders.
- Differential metabolites varied between genders at each energy level, indicating distinct metabolic responses.

## Abstract

Energy and protein are vital nutrients for livestock, and the demand for both varies between different genders. The gut microbiota plays an important role in the host’s nutrient utilization and immunity. This study focuses on the effects of hindgut microbiota and metabolism on female and male Leizhou goats when consuming a 10% crude protein diet at four energy levels. It concluded that female and male goats exhibit distinct metabolic abilities when consuming a 10% crude protein diet at four different energy levels, providing a gender-based reference basis for formulating low-protein dietary strategies in goats.

The gut microbiota plays a crucial role in maintaining the host’s metabolism and can influence the host’s productivity. Both dietary composition and gender have distinct effects on the composition of the gut microbiota. Therefore, to investigate the differences in the structure and function of the gut microbiota between female and male goats, we analyzed their fecal microbiota and metabolites when fed a 10% crude protein diet at four different energy levels—7.01, 8.33, 9.66, and 10.98 MJ/kg DM. Four non-pregnant female and four male Leizhou goats (all 8 months of age) were used in the experiment, with an average body weight of 10.3 ± 0.8 kg for females and 13.6 ± 1.1 kg for males (mean ± SD). The animals were assigned to two separate 4 × 4 Latin square designs according to their gender, each consisting of four treatments and four 28-day periods, including 25 days of a dietary adaptation period and 3 days of fecal sample collection per period. The data were analyzed using the SAS statistical package and Pearson’s correlation analysis. The dominant phyla for all samples were Firmicutes and Bacteroidota, regardless of dietary energy levels or gender. Among fecal bacteria, unclassified_f_Lachnospiraceae was the dominant genus in the female goats, and Oscillospiraceae_UCG-005 was the dominant genus in the male goats. The relative abundance of unclassified_f_Lachnospiraceae (p < 0.001), Bacteroides (p = 0.007), norank_f_Ruminococcaceae (p = 0.024), Mediterraneibacter (p = 0.001), and norank_f_Muribaculaceae (p = 0.008) was greater in the female goats than in the male goats. In contrast, the relative abundance of Oscillospiraceae_UCG-005 (p < 0.001), Ruminococcus (p = 0.035), Monoglobus (p = 0.006), Oscillospiraceae-NK4A214_group (p = 0.008), norank_f_F082 (p < 0.001), and Prevotellaceae_UCG-003 (p < 0.001) was lower in the female goats than in the male goats. The volcano plot showed that there were 153, 171, 171, and 183 differential metabolites between the female and male goats at dietary energy levels of 7.01, 8.33, 9.66, and 10.98 MJ/kg DM, respectively. Numerous correlations were observed between differential metabolites and microflora genera. We concluded that the non-pregnant female and male goats exhibited distinct metabolic abilities when consuming a 10% crude protein diet at four different energy levels. Interestingly, in the female and male goats, the fecal microbiota also showed some differing responses to the energy levels. These results provide a gender-based reference for formulating low-protein dietary strategies for 8-month-old Leizhou goats.