Histological Changes of Saanen Goat Mammary Gland in the First Pregnancy Following the Consumption of Saturated and Unsaturated Fats

The aim of this study was to investigate the effect of saturated and unsaturated fat sources in the diet of late pregnancy and early lactation on histological changes in the mammary gland of nulliparous Saanen goats. Thirty does from the second half of pregnancy were divided into three groups based on body weight. For each group, the diet contained either: 1) saturated fat (positive control, C+), 2) roasted soybeans (omega-6, SB), or 3) extruded flaxseeds (omega-3, FS). Milk production was determined weekly and mammary tissue sampling was performed three times after kidding and the histological information of the mammary tissue was obtained using Image J software. The results showed that consumption of flaxseed and soybean increased milk production in the whole period compared to the C+ group (P<0.05).  The percentages of epithelial cells and stroma were the highest and the lowest, respectively in the FS group compared to the other groups(P<0.05). The areas of alveoli, lumen, epithelium and the number of epithelial cells per alveolus were higher in the SB group; however, the number of alveoli per unit area  was lower in SB group than  in the other groups (P<0.05). Based on the results, it is concluded that the consumption of diets rich in unsaturated fatty acids, especially omega-3 fatty acids, in critical periods of mammary gland growth, affects growth and development of mammary tissue, improves lactation performance and increases milk production.