The article discusses the importance and role of fungal directfed microbials (DFM) and anaerobic rumen fungi (ARF) in ruminants and their metabolic pathways of plant fibre decomposition, as well as rumen fermentation processes. ARF classification, enzymatic activity, impact on rumen metabolism,...

The study concerns the effect of wheat germ expeller (WGE) as a feed additive given to male Ross-308 broiler chickens on their meat’s energy and nutritional value, and coverage of nutrient reference values-requirements (NRV-R) of consumers for particular minerals. The chickens in the control group (CT—Control Treatment) were fed a standard complete mix. The experimental groups (EX5, EX10, EX15) were given a feed in which wheat middling was replaced with 5, 10, and 15% WGE. The breast and thigh muscles of 32 randomly selected chickens (8 in each group) were analyzed. More water, crude protein, P, Mg, Fe, Cu, and Mn were determined in the breast muscles, and more crude fat, crude ash, Ca, and Zn in the thigh muscles. Chickens from the CT group consumed significantly (p ≤ 0.01) less feed per body weight than those from groups EX5 to EX15, but achieved the highest body weight per 100 g of consumed feed. A higher (p ≤ 0.01) feed, energy, crude protein, and crude fat intake was observed in groups EX5 to EX15 compared to CT. The higher (p ≤ 0.01) value of protein efficiency ratios was indicated in the CT group. The WGE additive did not impact the muscles’ energy values but affected the nutritional value. The daily consumption of 100 g of breast muscles to a large extent covers the consumer NRV-R for P, Mg Fe, Cu, and Mn. However, thigh muscles cover the NRV-R to a greater extent for Ca and Zn. The EX15, EX5, and EX10 muscles covered most of the NRV-R for P, Ca, and Mg, while the CT muscles did the same for Zn and Mn. Adding 5% WGE to broiler feed is optimal as it does not impair the nutritional value of the muscles.

The aim of this study was to examine the influence of the level (1, 3, and 5 mg I/kg) and source of iodine (KI, Ca(IO₃)₂, and KIO₃) on thyroid hormone and immunoglobulin concentrations in the blood serum of laying hens alongside a histological picture of the thyroid. In the first, birds were fed grain–soybean meal mixtures, and in the second, two kinds of diets based on corn–soybean or corn–soybean–rapeseed meal were applied. In the experiments, we determined the levels of the blood serum thyroid hormones fT₃ and fT₄, as well as the morphological structure of the thyroid gland. In the second experiment, the concentration of immunoglobulins in blood serum was assayed. In both experiments, no influence of iodine source on thyroid hormone concentration was observed. However, increasing the iodine level in the full mixture and adding rapeseed meal in both experiments caused an increase in fT₃ concentration. Increasing I-addition in both experiments led to a decrease in thyroid gland follicle diameter. Rapeseed meal inclusion (at a level of 10%) to the complete hen mixture led to an increase in thyroid gland follicle diameter. Applying KIO₃ as an iodine source in both experiments caused a decrease in the thyroid gland height of follicle epithelial cells. Immunoglobulin concentrations in the serum were not affected by experimental factors. The results suggest that the methodologies of studies on the bioavailability of minerals and the corresponding analytical methods require unification. The lack of such standardization makes it impossible to engage in a satisfactory discussion of the results and exchange experiences.

The following study focuses on a comparison of the effectiveness of egg content enrichment with selenium (Se) via application of sodium selenite (Na-selenite), selenium-enriched yeast (Se-Yeast), or selenomethionine (Se-Met) in laying hen diets. Two hundred sixteen laying hens were divided into four treatments, each comprising eighteen replications, and each with three hens per cage. Animals were fed a basal diet without Se supplementation (control: selenium content 0.058 mg/kg), with the addition of Na-selenite, Se-Yeast, or Se-Met in amounts equivalent to 0.3 mg/kg of added selenium. The egg quality, the selenium content in eggs after the third and the fifth months of using Se supplementation, and the selenium level in the liver were determined. Enrichment of egg content with selenium was the most effective (382 μg/kg) via application of dietary Se-Met. Application of Na-selenite and Se-Yeast led to a similar effect on Se-accretion in egg content (255.9 and 258.9 μg/kg, respectively). Additionally, the calculated average Se concentration in one fresh egg was also higher in eggs from hens that received selenium additives in their diet and was far higher, almost three times higher for Se-Met addition, than the concentrations in controls. Se-accretion in the liver wet tissue was greater following application of Se-Yeast in the diet than following other treatments. These results indicate that the use of selenomethionine in the laying hen diet is the best method of enriching eggs with this micronutrient. In turn, the eggs obtained in this way can be an excellent source of highly bioavailable selenium in the human diet.

An in vitro experiment was conducted to determine the impact of silage produced from selected varieties of sorghum on the microbial fermentation profile of cows’ ruminal fluid. To determine the main microbial fermentation products, ruminal fluid samples were obtained from Polish Holstein–Friesian cows. Serum bottles were filled with 80 mL of ruminal samples, and 1 g of one of the following substrates was added: corn silage (CS), grass silage (GS), rye silage (RS), sorghum silage (sweet) (SS1), sorghum silage (grain) (SS2) or sorghum silage (dual-purpose) (SS3). The serum bottles were flushed with CO₂ and fermented for 8 and 24 h at 39 °C. After incubation, the obtained gas and rumen fluid were then analysed to determine the methane and volatile fatty acid (VFA) contents using gas chromatography. The use of sorghum silage (SS) resulted in a decrease in the total concentration VFA concentration in the ruminal fluid compared with the use of other silages, especially GS. Moreover, the ruminal fluid contained a lower molar proportion of propionic and butyric acids when SS was used compared with CS. The butyric acid proportion was higher in SS samples than in RS samples. The differences in chemical composition between sorghum varieties did not influence the rumen VFA concentration or profile. A decrease in gas production, but without effects on methanogenesis, was observed when SS was used compared with GS and CS. The analysis demonstrates the physiological processes of fermentation in the rumen, as evidenced by the products of microbial fermentation. The main advantage is that the addition of SS, irrespective of the plant variety, reduced fermentation gas production in the ruminal fluid compared with CS. The silage of the analyzed sorghum varieties may be used in the diets of dairy cows as a substitute for corn and grass silages.