Rapeseed is a high-quality protein source; however, its quality primarily depends on the variety, origin, and processing method. This study aimed to examine the effectiveness of a mineral supplement (“Peelko”; 27% Ca, 3.5% Mg, 800 mg/kg Fe) in terms of whether it is suitable for reducing the remaining antinutritional substances in cold-pressed rapeseed cake, thereby improving the nutrient content and digestibility of rapeseed. The experiment was carried out with 600 Ross-308 broilers divided into three feeding groups: the control diet contained extracted soybean meal, the R treatment included 10–15% cold-pressed rapeseed cake (in grower and finisher phases), and the R+ treatment consisted of the mineral supplement in addition to the cold-pressed rapeseed cake. R+ had a beneficial effect on the FCR in the grower and finisher feeding phases; moreover, it increased the weight of thyroid glands and the T3 and T4 hormone levels in the blood serum to a lesser extent than R when compared to C (p < 0.05). Diet-specific changes could be observed through the histological examination of thyroid glands, where the acini became larger when the unsupplemented cold-pressed rapeseed cake was fed (R group). Using the mineral supplement (R+ diet) decreased the acinus diameter compared to the R diet, with a similar value to that observed in control birds. The protein content in the breast and fat content in the thigh showed milder changes in R+ than R, compared to C (p < 0.05). The relative ratio of n-6 and n-3 fatty acids narrowed in both R and R+ meat samples compared to C (p < 0.05). R+ may have a more favorable effect on oxidation processes according to the better MDA values in fresh meat (p < 0.001) and samples after 1–2 months of storage (p < 0.05) than R when compared with C. The negative modifications in the color parameters (L*, a*, and b*) and the organoleptic properties of the meat were less significant with R+ than R, compared to the control (p < 0.05). According to the results of this study, the R+ treatment was able to reduce the antinutritional effects of rapeseed, as evident from the properties of the resulting animal products.

Background: Sows are exposed to severe stress and hormonal challenges during their whole productive life. As polyunsaturated fatty acids play an important role in immune and reproductive functions, with a better understanding of their role in breeding sows’ nutrition, improved performance and more sustainable pig production can be achieved. Objectives: In this study, we investigated the effects of omega-6 and omega-3 fatty acid supplementation on the antioxidant status and hormone levels of sows. Methods: A total of 48 Danish Large white × Danish Landrace sows were supplemented either with sunflower oil (SO) as a control group or with fish oil (FO) as experimental group at the same dose of 10 g/kg feed. Blood samples were collected on day 14 of lactation, 5 days after weaning (insemination), and 30 days after insemination. To estimate antioxidant and reproductive effects, the amounts of reduced glutathione (GSH), thiobarbituric acid reactive substance, the activity of glutathione peroxidase (GPx), serum 17β oestradiol (E2), progesterone (P4), and 6-keto prostaglandin F1α (6-keto PGF1α) levels were investigated. Results: FO-based supplementation increased GPx activity on day 14 of lactation. Five days after weaning, the concentration of GSH in FO-fed sows was significantly higher than that in SO-fed sows. The E2 content of blood was significantly lower in the experimental group than in the control group for two of the three examined periods (day 14 of lactation and 30 days after insemination), whereas P4 levels were significantly higher in the experimental group 5 days after weaning. We found that 6-keto PGF1α levels were systematically lower in the experimental group throughout the trial. Conclusions: This study provides evidence of the major impact of omega-6 and -3 fatty acids on the tested hormone levels, which serve as precursors for the production of E2 and P4 but have an opposite effect on PGF2α production.

Near-infrared (NIR) spectroscopy was employed to determine the differences between forage mixtures of winter cereals and Italian ryegrass and to evaluate fermentation characteristics of mixed silages. Forages were harvested on five phases (Cuts 1–5), with 1 week interval (n = 100). The yield of the last harvest (Cut 5) was ensiled and analyzed on four different days (D0, D7, D14, and D90) (n = 80). Principal component analysis based on the NIR data revealed differences according to the days of harvest, differences between winter cereals and Italian ryegrass forages, and differences in the fermentation stages of silages. The partial least square regression models for crude protein (CP), crude fiber (CF), and ash gave excellent determination coefficient in cross-validation (R²CV > 0.9), while models for ether extract (EE) and total sugar content were weaker (R²CV = 0.87 and 0.74, respectively). The values of root mean square error of cross-validation were 0.59, 0.76, 0.22, 0.31, and 2.36 %DM, for CP, CF, EE, ash, and total sugar, respectively. NIR proved to be an efficient tool in evaluating type and growth differences of the winter cereals and Italian ryegrass forage mixtures and the quality changes that occur during ensiling.

The effects of n-6 and n-3 fatty acid supplementation on the fatty acid profile of sow milk were investigated using traditional fatty acid analysis and a novel method of the electronic nose (EN). The control group received 6.3 g of sunflower oil (SO) rich in n-6 fatty acids per kg feed, and experimental animals received the same amount of fish oil (FO) as an n-3 fatty acid source. The diets were corn- and soybean meal-based diets. Supplementation of SO enhanced the amount of linoleic acid (C18:2, n-6) (SO: 8.43 mg/mL vs. FO: 6.63 mg/mL milk), and significantly increased (p < 0.02) the amount of total polyunsaturated fatty acids (SO: 9.92 mg/mL vs. FO: 8.61 mg/mL milk) in the sow’s milk. On the contrary, FO significantly increased the amount of n-3 polyunsaturated fatty acids (FO: 1.17 mg/mL vs. SO: 0.69 mg/mL milk), especially eicosapentaenoic acid (C20:5, n-3), docosapentaenoic acid (C22:5, n-3), and docosahexaenoic acid (C22:6, n-3), in the milk (p < 0.001). FO and SO supplementation did not affect the analytical composition of milk. Milk samples collected from the differently fed individuals could be clearly separated according to the feeding groups based on the odour profile described by the EN.