The Effect of Flaxseed on the Porcine Uterus

Flaxseed is an important supplement in animal feed. It contains high levels of polyunsaturated fatty acids and lignans acting as phytoestrogens, which can alter cell functions in various organs. The aim of this work was to analyse the effect of supplemental flaxseed in pigs on the morphophysiological properties of the uterus. The experiment included 12 Landras fattening pigs. The control group was fed with a standard feeding mixture for fattening pigs and the experimental group was fed a standard mixture with an addition of 10 % milled flaxseed. After six weeks of fattening, six animals of each group were slaughtered and samples of the uterine horns were taken for the routine histological (height of the endometrium and its compartments, number of endometrial glands, and myometrium height) and for immunohistochemical (expression of oestrogen and progesterone receptor markers) analyses. In the experimental group fed a flaxseed supplement, significant thickening of the superficial epithelium, endometrium, and lamina propria layer was found. The number of endometrial glands was higher than in the control uteri by about 1/3. Moreover, a flaxseed-enriched diet significantly increased the expression of oestrogen receptors α and β, as well as progesterone B receptors in all uterine compartments. The addition of flaxseed in the feed for six weeks had a stimulating effect on the monitored parameters of the uterus of fattening pigs.