# The Housing System Contributes to Udder Health and Milk Composition
## 3 Results
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Specification**} & \multicolumn{3}{c}{**Housing System (HS)**} & \multicolumn{3}{c}{**SCC Class (ths mL-1)**} & \multirow{2}{*}{**SE**} & \multicolumn{3}{c}{\(p\)**-Value**} \\ \cline{2-2} \cline{4-10}  & **Tie-Stall** & & & & & & & & \(p\)**-Value** & \\ \hline Number of milk & 198 & 221 & 210 & 101 & 66 & 42 & & & \\ samples & 3.59 & 3.52 & 2.7 \({}^{\mathrm{Bb}}\) & 4.1 a & 4.5 \({}^{\mathrm{A}}\) & 4.5 \({}^{\mathrm{A}}\) & 0.101 & 0.123 & 0.000 & 0.234 \\ Lactation day & 169.1 & 173.3 & 161.2 \({}^{\mathrm{b}}\) & 181.4 \({}^{\mathrm{ab}}\) & 186.2 \({}^{\mathrm{a}}\) & 188.5 \({}^{\mathrm{a}}\) & 4.632 & 0.231 & 0.042 & 0.355 \\ SCC (ths mL-1) & 311.3 & 383.1 & 87.4 & 288.6 & 574.2 & 1203.8 & 16.345 & & & \\ Ln SCC & 12.65 \({}^{\mathrm{B}}\) & 12.85 \({}^{\mathrm{A}}\) & 11.2 \({}^{\mathrm{D}}\) & 12.6 \({}^{\mathrm{C}}\) & 13.2 \({}^{\mathrm{B}}\) & 14.0 \({}^{\mathrm{A}}\) & 0.056 & 0.000 & 0.000 & 0.863 \\ Daily ECM yield & 20.5 & 21.8 & 24.4 \({}^{\mathrm{Aa}}\) & 20.4 \({}^{\mathrm{b}}\) & 17.0 \({}^{\mathrm{B}}\) & 15.3 \({}^{\mathrm{Ba}}\) & 0.478 & 0.873 & 0.000 & 0.004 \\ Fat (\%) & 3.89 \({}^{\mathrm{B}}\) & 4.11 \({}^{\mathrm{A}}\) & 3.95 & 4.01 & 4.00 & 4.12 & 0.038 & 0.000 & 0.452 & 0.188 \\ Protein (\%) & 3.41 & 3.37 & 3.33 & 3.34 & 3.63 & 3.28 & 0.056 & 0.891 & 0.237 & 0.898 \\ Casein (\%) & 2.55 & 2.56 & 2.54 & 2.65 & 2.61 & 2.55 & 0.013 & 0.733 & 0.188 & 0.075 \\ Lactose (\%) & 4.70 & 4.65 & 4.77 \({}^{\mathrm{A}}\) & 4.68 \({}^{\mathrm{a}}\) & 4.56 \({}^{\mathrm{Bb}}\) & 4.37 \({}^{\mathrm{Bb}}\) & 0.018 & 0.067 & 0.000 & 0.254 \\ Dry matter (\%) & 12.48 \({}^{\mathrm{B}}\) & 12.75 \({}^{\mathrm{A}}\) & 12.57 & 12.77 & 12.63 & 12.45 & 0.044 & 0.004 & 0.391 & 0.194 \\ Fat/protein ratio & 1.14 & 1.22 & 1.19 & 1.20 & 1.10 & 1.25 & 0.159 & 0.377 & 0.293 & 0.256 \\ Urea (mg 1-1) & 193.5 \({}^{\mathrm{b}}\) & 214.4 \({}^{\mathrm{a}}\) & 193.2 & 214.6 & 221.7 & 213.4 & 4.155 & 0.015 & 0.124 & 0.069 \\ BCS & 3.2 & 3.1 & 3.1 & 3.2 & 3.2 & 3.1 & 0.025 & 0.322 & 0.298 & 0.219 \\ \hline \hline \end{tabular}  
* SCC—some cell count; ECM—energy-corrected milk; BCS—body condition score. Means followed by different letters differ within rows (within the factor): A, B, C, D (\(p\leq 0.01\)); a, b (\(p\leq 0.05\)).  
\end{table} 
Table 4: The effect of the housing system and udder health on milk yield and composition. An analysis of the major fatty acids in milk fat revealed that their proportions in total fatty acids were affected by the housing system and SCC class (Table 6). Tie-stall housing, compared with free-stall housing, contributed to a significant increase in the proportions of trans-vaccenic acid (TVA), linolenic acid (LNA), conjugated linoleic acid (CLA), and docosahexaenoic acid (DHA). The concentration of arachidonic acid (AA) was higher (\(p<0.05\)) in milk from cows kept in the free-stall system. The proportions of butyric acid (BA) and oleic acid (OA) decreased (\(p<0.05\)), whereas the proportions of linoleic acid (LA), AA, and docosapentaenoic acid (DPA) increased (\(p<0.05\)) with increasing SCC. Figure 1: The effect of the housing system \(\times\) somatic cell count (SCC) interaction on daily milk yield (means \(\pm\) SEM): A, B (\(p\leq 0.01\)); a, b (\(p\leq 0.05\)).