Succession of rumen microbiota and metabolites across different reproductive periods in different sheep breeds and their impact on the growth and development of offspring lambs

Abstract

Background: The microbiota and metabolites in the gastrointestinal tracts of female animals at different reproductive periods are very important to the growth, development, and health of themselves and their offspring. However, the changes in the gastrointestinal microbiota and metabolites throughout reproductive period of different sheep breeds and their effects on the growth and development of offspring lambs are still unclear. Hence, this study presents an assessment of the reproductive hormone levels, immune levels, rumen microbiota, and metabolites in Hu sheep and Suffolk ewes at different reproductive periods and their effects on the growth and development of offspring lambs.

Results: Hu sheep and Suffolk during non-pregnancy, pregnancy, and lactation were used as the research objects to determine reproductive and immune indexes of ewes at different periods, analyze rumen microbiome and metabolome, and track the growth performance and development of offspring lambs. The results showed that the reproductive hormone and immune levels of Hu sheep and Suffolk underwent adaptive changes across different reproductive periods. Compared with non-pregnancy, the microbial energy metabolism and lipid metabolism function decreased during Hu sheep pregnancy, and energy metabolism function decreased during lactation. In Suffolk, energy metabolism, glycan biosynthesis, and metabolism function were enhanced during pregnancy, and the metabolism of cofactors and vitamins was enhanced during lactation. Prevotella increased in Suffolk during pregnancy and lactation (P < 0.05) and was positively correlated with the birth weight and body size of the lambs (P < 0.05). Moreover, the abundances of Butyrivibrio and Rikenellaceae_RC9_gut_group during pregnancy were positively correlated with the intestinal immunity of the offspring lambs (P < 0.05), thereby regulating the intestinal immunity level of the lambs. Metabolomic analysis revealed that the protein digestion, absorption, and amino acid metabolism of Hu sheep were enhanced during pregnancy, which provided amino acids for the growth and development of pregnant ewes and fetuses and was significantly correlated with the birth weight, body size, and intestinal immunity of lambs (P < 0.05). Simultaneously, there was an increase in acetate and propionate during the pregnancy and lactation period of both Hu sheep and Suffolk, providing energy for ewes during reproductive period. Moreover, the microbiota during the lactation period was significantly correlated with the milk quality and lambs daily gain (P < 0.05).

Conclusions: This study revealed the characteristic succession changes in the rumen microbiota and its metabolites at different reproductive periods in sheep breeds and their regulation of reproductive hormone and immune levels and identified their potential effects on the growth and development of offspring lambs. The findings provide valuable insights into the health and feeding management of different sheep breeds during the reproductive stage. Video Abstract.

Keywords: Immune function; Lambs; Metabolites; Reproductive period; Rumen microbiota.

Fig. 1

Analysis of blood reproductive hormones and immune indexes in different reproductive periods of sheep breeds. A Reproductive hormone indicators. B Immunoglobulins and immune factors. C Blood physiological indicators. Different lowercase letters on the line chart represent significant differences (P < 0.05)

Fig. 2

Rumen microbial diversity and composition analysis of different breeds of sheep at reproductive stage. A, B, C, D Microbial diversity indicators, Shannon, Simpson indices of Hu sheep, and Suffolk. E, F Microbial composition at the level of phylum and genus. G LEfSe analysis. Note: HN, HP, and HL represent the non-pregnancy, pregnancy, and lactation period of Hu sheep respectively. SN, SP, and SL respectively represent the non-pregnancy, pregnancy, and lactation period in Suffolk

Fig. 3

Rumen microbial function through PICRUSt2 analysis of different breeds of sheep at different reproductive periods. Note: HN, HP, and HL represent the non-pregnancy, pregnancy, and lactation period of Hu sheep respectively. SN, SP, and SL respectively represent the non-pregnancy, pregnancy, and lactation period in Suffolk

Fig. 4

Analysis of rumen microbial metabolic profile at reproductive period of different breeds of sheep. A Differential metabolite quantity statistic. B Ruminal SCFA concentration of Hu sheep. C Ruminal SCFA concentration of Suffolk. D Concentration of ruminal ammonia nitrogen content. E1, E2, E3 KEGG functional enrichment map of differential metabolites of HN_vs_HP, HP_vs_HL, and HN_vs_HL, respectively. F1, F2, F3 KEGG functional enrichment map of differential metabolites of SN_vs_SP, SP_vs_SL, and SN_vs_SL, respectively

Fig. 5

Correlation analysis of rumen microbiota and metabolites with reproductive hormones in reproduction period. A RDA analysis of microbiota and reproductive hormones and immune indicators. B Heat map analysis of microbial correlations with reproductive hormones and immune indicators. C Heat maps of correlations between metabolites and reproductive hormones and immune indicators. D Heat maps of SCFA correlation with reproductive hormones and immune markers. Note: *P < 0.05, **P < 0.01, ***P < 0.001

Fig. 6

Correlation analysis of ewe’s ruminal microbiota and metabolites during pregnancy with developmental and immune indexes of newborn lambs. A Birth weight of newborn lambs. B Body size of newborn lambs. C1, C2, C3, C4, C5, C6 Immunoglobulin and immune factor concentrations in lamb intestinal feces. D RDA analysis of ewe microbiome during pregnancy and body size and immune indices of newborn lambs. E Heat maps of the correlation between pregnant ewe microbiome and body size and immune indices of newborn lambs. F WGCNA analysis of metabolites in ewes during pregnancy and body size and immune indices of newborn lambs. G Heat map of correlation between SCFA in ewes during pregnancy and body size and immune indices in newborn lambs. *P < 0.05, **P < 0.01, ***P < 0.001

Fig. 7

Correlation analysis of ewe’s ruminal microbiota and metabolites with milk quality and daily gain of lambs during lactation. A Milk quality analysis of Hu sheep and Suffolk. B Average daily gain of lambs during the ewes’ lactation period. C RDA analysis of ruminal microbiome and milk quality and average daily gain of lamb. D The correlation between SCFA and milk quality and average daily weight gain of lambs during the lactation period. E WGCNA analysis of ruminal metabolites and milk quality of ewes in lactation and average daily gain of lambs. *P < 0.05, **P < 0.01, ***P < 0.001

Fig. 8

Graphical summary of the effects of ruminal microbiota and its metabolites on the growth and development of offspring lambs at different reproductive periods of Hu sheep and Suffolk breeds. The two breeds of sheep in pregnancy period and lactation period were compared respectively. The red font represented upregulation of bacterial flora, metabolites, and KEGG function, while the green font represented downregulation. Firm, Firmicutes; Riken_RC9, Rikenellaceae_RC9_gut_group; Succin, Succiniclasticum; Prevo, Prevotella; F/B, Firmicutes/Bacteroidota; (6Z,9Z,12Z)-Octa, (6Z,9Z,12Z)-octadecatrienoic acid; 3-Meth, 3-methylcytosine; 4-(4-Meth)-4-oxoacid, 4-(4-methylcyclohexyl)-4-oxobutanoic acid; 2-Hy-2-ethy, 2-hydroxy-2-ethylsuccinic acid; BW, birth weight; Bdl, body diagonal length; CC, chest circumference; ADG, average daily gain