## 4 Discussion  
Milk fat contains a wide variety of fatty acids, on average 65-70% saturated fatty acids and 30-35% unsaturated fatty acids. Amongst saturated fatty acids in milk fat, there are around 10-12% short- and medium-chain and 50-55% long-chain. These acids consist of stearic acid (8-10%), myristic acid (10-12%), and palmitic acid (25-27%). Amongst unsaturated fatty acids in milk fat, there are 25-30% monounsaturated, where oleic acid is the second most abundant fatty acid in milk fat. The composition of milk fat varies slightly depending on the breed of animal, stage of lactation, season, geographical location, and feed composition. The stage of lactation and the feed are two important factors which may change the vitamin content in sheep and goat milk. The results obtained in this study indicate that organic sheep and goat milk was found to contain a higher amount of the fat-soluble vitamins in comparison to conventional. Although no significant differences were observed with respect to factors, such as stage of lactation, season, and feed composition, values of vitamins A and E varied slightly in conventional and organic farms. Some authors have reported that ewe's milk contains higher amounts of vitamins [22, 43] than the goat milk. In addition, a study showed higher contents of these vitamins in cow's and sheep's milks than in goat's milk [44], while other authors [45] have reported the opposite. In our study, the goat milk seems to be richer regarding the vitamin E while the sheep milk has more vitamin A in both organic and conventional milk compared to goat ones. The fat content present in sheep and goat milk is a rich source of MCFA. SCFA and MCFA are de novo synthesized in the mammary gland, from rumen fermentation of acetic acid and \(\beta\)-hydroxybutyric acid, both influenced by the energy balance of diet and the specificity of rumen micro flora [21]. Significant differences in SCFA were not found between organic and conventional farms. Lower concentrations of SCFA and MCFA in conventional farms compared to organic farms may be attributed to the feeding system and to reduced synthesis of fatty acid in the mammary gland. The sum content of MUFA in goat milk was slightly higher in organic farms than in conventional ones because of the increase in oleic acid and in gondoic acid. Oleic acid is considered to be favorable for health, because it lowers LDL cholesterol and triacylglycerol contents and reduces the risk for artery disease. PUFA concentrations were higher in the sheep milk of organic farms compared to these of conventional farms whereas MUFA concentrations were lower in sheep organic farms than in conventional farms. On the contrary, PUFA concentrations were lower in the milk from goat organic farms compared to those of conventional farms, whereas MUFA concentrations were higher in the goat milk of organic farms than that of the conventional farms. These differences are mainly attributed to different feeding practices used by the two production systems, as it has been also previously reported in literature [46, 47]. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Organic (n = 12)**} & \multicolumn{4}{c}{**Conventional (n = 12)**} \\ \hline  & **Mean** & **SD** & **Min** & **Max** & **Mean** & **SD** & **Min** & **Max** & _p-Value_ \\ \hline Vit E (\(\mu\)g/mL) & 2.51 & 1.22 & 1.88 & 4.09 & 2.26 & 1.12 & 0.64 & 4.68 & 0.233 \\ Vit A (\(\mu\)g/mL) & 0.90 & 0.21 & 0.56 & 1.06 & 0.93 & 0.25 & 0.55 & 1.28 & 0.275 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Fat-soluble vitamins content in organic and conventional sheep milk.