## 3 Results and Discussion  
### Overview of Included Studies  
A search in the WoS and ScP databases returned 162 results, which were added to Mendeley(r) and, after excluding duplicates, 111 studies remained--Figure 2. Of these 111 studies, 20 were excluded for not meeting the eligibility criteria of first stage (2 were written in languages other than English (Spanish and Portuguese); 12 were published as literature review; 4 were published in conference proceedings; and 2 were published as book chapters), and another 79 for not meeting the eligibility criteria defined in the second stage (14 were carried out in animal production systems other than CBPs; 2 were carried out in facilities for other animal types (beef cattle and horses); and 63 did not carry out a physicochemical evaluation/characterization of the bedding material and/or did not specify the place and period in which the bedding samples were collected). Finally, 12 articles were used to compose this systematic review. Table 2 lists detailed information on the selected studies of bedding evaluation and/or characterization, including authors, region, country where they were carried out, facility types and ventilation systems used, information related to the bedding being composted, and the study purpose. The 12 selected studies were published between 2007 and 2023, and this fact reinforces that CBP is a relatively recent housing system, compared to the confinement systems traditionally used in intensive production of dairy cattle (FS and TS). Such results are in line with what was verified by [PERSON] et al. [36], who conducted a bibliometric study and identified that the first article on CBP systems was published in 2007. As highlighted in Table 2, the selected studies were carried out in different countries: Brazil (\(n=5\)), Germany (\(n=1\)), and Italy (\(n=1\)), Spain (\(n=1\)), the Netherlands (\(n=1\)) and the United States of America (\(n=3\)). \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Reference**} & \multirow{2}{*}{**Place**} & \multicolumn{2}{c}{**Facility**} & \multicolumn{2}{c}{**Bedding**} & \multicolumn{2}{c}{**Study**} \\ \cline{2-9}  & & **FCT** & **VST** & **BM** & **BAA** & **BTO** & **Season** & **Purpose** \\ \hline Barberg & Minnesota & 12 CBPs with partially open & NV & Sa. + & & & Summer & Describe facility characteristics, bedding materials, and \\ et al. [30] & (USA) & partially open & LVHS & WC & 3.5–14.3 & 2 & & to fall [4] \\  & & sides [1] & HVLS 2 & WC & & & & \\ \hline \multirow{2}{*}{ \begin{tabular}{c} [PERSON] \\ et al. [19] \\ \end{tabular}  } & Minnesota & 6 CRPs with partially open & LVHS & CS, RS, OH, Sa, \\ et al. [19] & (USA) & sides [1] & HVLS 2 & CS, RS, OC, or WS [5] & 5.2–8.0 3 & 2 & \begin{tabular}{c} Winter, \\ spring, \\ summer, \\ and fall \\ \end{tabular}  & \begin{tabular}{c} Describe management practices in the milk production \\ activity in CBP systems using different bedding \\ materials in Minnesota (USA) \\ \end{tabular}  \\ \hline Black & Kentucky & 47 CBPs with partially open & NS & Sa. + WC, Sa, \\ et al. [11] & (USA) & sides [1] & NS & Sa. + WC, Sa, \\ et al. [11] & (USA) & sides [1] & NS & Sa. + WC, Sa, \\ et al. [11] & (USA) & sides [1] & NS & Sa. + WC, Sa, \\ et al. [11] & (USA) & sides [1] & NS & Sa. + WC, Sa, \\ et al. [11] & (USA) & sides [1] & NS & Sa. + WC, or OM [19] & 7.8-9.4 11 & 3 & \begin{tabular}{c} Winter, \\ summer, \\ and fall \\ \end{tabular}  \\ \hline \multirow{2}{*}{ \begin{tabular}{c} [PERSON] \\ et al. [31] \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} Hessen (DE) \\ et al. [31] \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} Hessen (DE) \\ et al. [31] \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} N. \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} N. \\ \end{tabular}  } & \multirow{2}{*}{\ \begin{tabular}{c} N. \\ \end{tabular}