## 3 Results
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & & **Days of Age** & & \\ \hline Item & 52 & 99 & 119 & 140 & 154 \\ \hline Number of samples 1  & 32 & 64 & 60 & 61 & 65 \\ Diversity indexes & & & & & \\ Nb of OTU & \(2\,709\pm 323\)2  & \(3\,666\pm 363\)2  & \(3\,660\pm 334\)2  & \(3\,719\pm 288\)2  & \(3\,726\pm 298\)2  \\ Shannon index & \(6.67\pm 0.17\)2  & \(7.14\pm 0.16\)2  & \(7.15\pm 0.13\)2  & \(7.19\pm 0.11\)2  & \(7.17\pm 0.11\)2  \\ Chao1 & \(3\,707\pm 506\)2  & \(5\,229\pm 876\)2  & \(4\,966\pm 731\)2  & \(5\,119\pm 583\)2  & \(5\,276\pm 670\)2  \\ ACE & \(3\,866\pm 563\)2  & \(5\,559\pm 980\)2  & \(5\,227\pm 814\)2  & \(5\,403\pm 649\)2  & \(5\,602\pm 772\)2  \\ Simpson & \(0.994\pm 0.003\)2  & \(0.997\pm 0.001\)2  & \(0.996\pm 0.001\)2  & \(0.997\pm 0.001\)2  \\ InvSimpson & \(209\pm 64\)2  & \(310\pm 68\)2  & \(284\pm 78\)2  & \(309\pm 75\)2  & \(324\pm 86\)2  \\ Fisher & \(949\pm 165\)2  & \(1\,512\pm 242\)2  & \(1\,467\pm 217\)2  & \(1\,543\pm 191\)2  & \(1\,548\pm 200\)2  \\ Phyla relative abundance (\%) & & & & & \\ Firmicutes & \(72.09\pm 7.61\)2  & \(80.31\pm 5.52\)22  & \(78.15\pm 5.05\)22  & \(78.44\pm 5.89\)2  & \(78.30\pm 6.77\)2  \\ Bacteroides & \(22.56\pm 7.82\)2  & \(15.02\pm 5.26\)22  & \(16.18\pm 5.14\)2  & \(15.17\pm 5.66\)2  & \(13.26\pm 3.90\)2  \\ Spirochaetes & \(0.34\pm 0.88\)2  & \(0.18\pm 0.28\)2  & \(0.47\pm 0.45\)2  & \(0.70\pm 0.49\)2  & \(1.33\pm 1.28\)2  \\ Actinobacteria & \(0.66\pm 1.12\)  & \(0.71\pm 1.16\)2  & \(0.26\pm 0.20\)2  & \(0.20\pm 0.09\)2  & \(0.21\pm 0.15\)2  \\ Proteobacteria & \(0.58\pm 0.51\) & \(0. Microbiota composition of finishing pigs clustered into two enterotypes at 99, 140, and 154 days of age, referred as finishing enterotype 1 (FE1) and finishing enterotype 2 (FE2) (Figure 2b and Figure 54). The microbial diversity in FE1 was greater compared to FE2 according to the number of OTU (\(3786\pm 320\) vs. \(3611\pm 303\), \(p<0.001\)) but the Shannon index did not differ (\(7.16\pm 0.13\) vs. \(7.13\pm 0.14\), \(p=0.73\)). In the FE1 enterotype, _Lactobacillus_ and _Erysipelotrichaceae incertae seds_ were more abundant, whereas the FE2 enterotype was dominated by _Turicibacter_, _Clostritium sensu strictio_, _Sarcina_, _Clostritium XI_, _Treponema_, _Fibrobacter_, _Corynebacterium_, _Staphylococcus_, and _Clostritium IV_ (\(p<0.05\)). The ADG, ADFI, and FCR did not differ between the enterotypes FE1 and FE2 (Table 2). At 119 days of age, a third enterotype named FE3 was observed with intermediate genera relative abundance between FE1 and FE2 (Figure 2b and Figure S4). Pigs in FE3 had greater ADG between 113 and 119 days of age compared to pigs in FE2. However, no significant difference was observed later in the experiment or between FE3 and FE1 (Table 2). The four experimental groups (CC, DC, CD, and DD) were equally represented in FE1, in FE2, and in FE3 (\(p=0.50\) in a Chi-squared test). Figure 1: Evolution of the relative abundance of 10 main genera across ages in female pigs. Figure 2: Relative abundance (%) of the three main genera contributing (**a**) to the two enterotypes in post-weaning enterotype 1 (PWE1) (in orange) and enterotype 2 (PWE2) (in green) and (**b**) to the three enterotypes in finishing enterotype 1 (FE1) (in red), finishing enterotype 1 (FE2) (in turquoise), and finishing enterotype 1 (FE3) (in grey). A total of 13 pigs moved from PWE1 enterotype to FE1, 23 from PWE1 to FE2, 13 from PWE2 to FE1, and 16 from PWE2 to FE2 (Figure 3a). In post-weaning, castrated males and females were equally represented in the enterotypes (\(p=1.00\) in a Chi-squared test). At 99 days of age, sex impacted the enterotype, with the females more represented in the FE2 compared to the FE1 (\(p<0.001\)). However, at 154 days of age, the enterotype was independent of the sex (\(p=0.69\)).