Diabetes mellitus represents one of the most widespread diseases in civilization nowadays. Since the costs for treating and diagnosing of diabetes represent several billions of dollars per year, a cheap, fast, and simple sensor for diabetes diagnosis is needed. Electrochemical insulin sensors can be considered as a novel approach for diabetes diagnosis. In this study, carbon electrode with electrodeposited NiO nanoparticles was selected as a suitable electrode material for insulin determination. The morphology and surface composition were studied by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS). For a better understanding of insulin determination on NiO-modified electrodes, the mechanism of electrochemical reaction and the kinetic parameters were studied. They were calculated from both voltammetric and amperometric measurements. The modified carbon electrode displayed a wide linear range from 600 nM to 10 µM, a low limit of detection of 19.6 nM, and a high sensitivity of 7.06 µA/µM. The electrodes were stable for 30 cycles and were able to detect insulin even in bovine blood serum. Additionally, the temperature stability of this electrode and its storage conditions were studied with appropriate outcomes. The above results show the high promise of this electrode for detecting insulin in clinical samples.

This study’s objective was to determine the impact of dietary humic substances on immune response and blood profiles in piglets. A total of 24 crossbred piglets (Slovakian White × Landrace; 35 days old; average body weight of 11.67 kg) were allotted to two dietary groups with (experimental; 5 g·kg⁻¹) or without (control; 0 g·kg⁻¹) natural humic substances supplementation. In this study, we observed a significant increase of the proportion of CD4+CD8- lymphocytes (p < 0.001) in the experimental group. The results also showed a tendency for an increase of the phagocytic activity and the engulfing capacity of phagocytes and the numbers of the other monitored lymphocyte subpopulations (CD3+, CD21+, CD4-D8+, CD4+CD8+, CD4+CD25+) in piglets in the experimental group compared to the control group. Supplementation of humic substances increased serum alkaline phosphatase compared to the control group (p < 0.05). Other monitored blood parameters were not significantly affected by dietary treatment. It concluded that inclusion of humic substances in the diet of piglets could have a stimulating effect on cellular immunity, without a negative effect on haematological and biochemical parameters.

The aim of this study was to evaluate the effects of nutrition on the milk urea nitrogen (MUN) concentration; on the transformation of N in the farm’s conditions; and there-by allow the milk urea nitrogen concentration to serve as a tool to maximize the protein nutrition and the metabolism of the cows. The relations evaluated by linear or multiple regression confirmed that the highest nutritional effects of the crude protein (CP) on the MUN concentration, which represented a 69.3 % variation in the MUN content. According to the CP content in the total mix ration (TMR) and MUN content (3150 milk samples) under farm conditions, a regression relationship was determined for the estimated of MUN (mg.dl ^–1 ) = –13.2 + 0.16 × CP (g.kg ^–1 dry matter). For multiple regression, the rate of variation expressed by this relationship increased to 72 for nutrient content and 78.3 % for nutrient intake in the TMR. The efficiency of nitrogen utilization (ENU) determined by calculations based on the MUN content according to the regression equations represented a negative correlation (P < 0.0001; R2 = 0.854) with respect to the CP content in the TMR and that the increased CP content by 1 % in the range of 14 to 18 % in the TMR decreased the ENU by 1.48 %. Validation of the models for prediction of nitrogen transformation (ENU) for practical application on the farms determined the best equation, which used the available data from the routine analysis of Breeding services of Slovakia. After taking into consideration of our breeding conditions, it was confirmed that the equation of ENU had taken into account the MUN, in addition to the amount of the milk produced.

The work evaluates the content of nutrients, rumen digestibility of NDF, degradability of CP, and intestinal digestibility of rumen un-degradable proteins in protein forages and concentrated feeds. The analysis of nutrient content confirmed along with the increase of plant maturity expressed by the increase of NDF, a significant decrease of NFC and CP in the regression dependence R2 = 0.7649 and R2 = 0.7116, respectively. The in situ method after 30 hours of incubation confirmed the higher NDF digestibility (P <0.001) of young roughages. The degradability of CP in alfalfa and grass silages was on average 78.7 ±6.1% or 63.7 ±9.7%. Higher protein degradability was confirmed in early-stage forages compared to mature forages for alfalfa (P <0.05) and grass (P <0.01) silages. Intestinal digestibility of un-degradable proteins determined by the modified three-step method was on average 64.1 ±2.5% in alfalfa silages and 51.0 ±5.6% in grass silages, with a statistically significant decrease (P <0.05) in mature forages. The obtained values of rumen degradability of crude protein confirmed a significant difference (P <0.001) between concentrates ranging from 20.3 to 76.0% (mean 58.1 ±3.0%) according to heat treatment. Intestinal digestibility of un-degraded protein varied from 54.5 ±1.4% in raw soybean to 95.2 ±1.0% in corn gluten feed. This study showed that the digestibility factor of crude protein and intestinal digestibility methods for protein feeds can be used in models to optimize the protein nutrition of dairy cows.

The effect of humic substances on growth performance, excretion, and the digestive organs was studied in pheasant chickens. Three hundred 1-day-old pheasant chicks were assigned to two equal groups. Chicks in the experimental group were fed diets supplemented with humic substances (5 g/kg). Chickens in the experimental group reached significantly higher average daily weight gains (p ˂ 0.05) in the second phase of rearing (29–49 d) at a significantly better feed conversion ratio (p ˂ 0.05). The supplementation of humic substances led to a significant increase in the average body weight of pheasants at the end of the experiment (p ˂ 0.05), and to a significant increase in average daily weight gains for the entire monitored period (p ˂ 0.05). In the experimental group, significantly higher relative weights of the gizzard (p ˂ 0.05), small intestine (p ˂ 0.05), and jejunum (p ˂ 0.05), along with a significantly larger relative length of the duodenum (p ˂ 0.05), were recorded. A significantly higher concentration of dry matter in the droppings of pheasants was found in the experimental group than in the control group (p ˂ 0.05). According to our results, feeding humic substances had the most beneficial effect on pheasant growth performance during the growing phase. Humic substances can also have a positive effect on the microclimate within the breeding facility. Reductions in the water content of droppings contribute to a reduction in the humidity of the litter, thus limiting the activity of nitrogenic bacteria.