The work focused on the study of the immunomodulatory and gutprotecting effect of humic substances (HS) in broilers. The diet of experimental chicks was enriched with 0.8% of HS. We noted that HS had a stimulatory effect on the phagocytic activity and the engulfing capacity of phagocytes, however, the level of oxidative burst of phagocytes was not affected. We observed a significant increase of CD4+: CD8+ lymphocyte ratio, an indicator of immune stimulation. HS did not influence the IgA gene expression. In contrast, we observed a significant increase in the expression of MUC-2 (intestinal mucin 2) gene, and a decrease in the expression of IGF-2 (insulin-like growth factor 2) and also AvBD2 (avian beta defensin 2) genes. A decreased Enterobacteriaceae counts in the gut of experimental animals showed a positive effect on intestinal microbiota. We confirmed a gut-protecting and an immunostimulatory effect of HS in broiler chickens.

Humic substances are currently being considered as a new feed component in replacement of antibiotic growth stimulators to improve growth and health in animals. The aim of our work was to evaluate the effect of the addition of humic substances to the feed at concentrations of 0.8% and 1.0% on the growth parameters, carcass yield, selected blood enzymes, minerals, and the bone quality in broiler chickens. One hundred fifty COBB 500 one-day-old male broiler chicks were randomly divided into one control and two experimental groups (n = 50) with three replications (16, 16 and 17 per pen), and fattened for 35 days. The broilers of the experimental groups (H0.8 and H1.0) were fed commercial feed mixtures with added humic substances (at 8 g·kg-1 and 10 g·kg-1). The control group was fed a diet without the addition of humic substances. A slight increase in the final body weight and feed conversion ratio was noted in the experimental groups (P > 0.05). Significantly higher yields of breast and thigh meat (P < 0.05) were recorded for the experimental group H1.0. The blood cholesterol level was lower for both experimental groups. A lower concentration of alkaline-phosphatase was observed in group H1.0. A decrease in aspartate aminotransferase and calcium was recorded for group H0.8. A significantly higher content of calcium and lower content of phosphorus was found in the bones of experimental animals. The 1% addition of humic substances had a positive impact on growth parameters (P > 0.05), improved selected blood indices and increased the calcium content in the bones of broilers (P < 0.05).

Multiple factor analysis was used for the examination of meat quality of broilers, the diet of which was supplemented with 0.8 and 1.0% addition of humic substances ( HS ). One hundred fifty COBB 500 one-day-old male broilers chicks were randomly divided into 3 different groups: one control and 2 experimental (n = 50), and they were fattened for 35 D. Subsequently, the meat quality was analyzed and defined by physicochemical and sensory quality, supplemented with analysis by instrumental methods. We observed changes in dry matter, fat, water, and protein content in experimental samples of breast and thigh meat ( P < 0.001). In both experimental groups, the concentration of phosphates and pH decreased in breast meat ( P < 0.001) and in thigh meat ( P < 0.05). The smell of experimental chicken breast meat samples after cooking was evaluated by a sensory panel, which scored a higher point score than that of the control group ( P < 0.05). Sensory evaluation of taste indicated a positive response with respect to the perception of meat quality in relation to a greater supplementation of HS in the diet. Thigh meat samples showed a variable extent of water loss after cooking, but lower values of water loss were generally obtained from thigh meat samples of poultry fed with higher HS supplementation, than in chicken breast meat samples. Significant differences in evaluated variables between both experimental groups were not observed. The color of breast meat samples changed, when considering the variables of lightness and redness, with the addition of 1% HS ( P < 0.05). The main advantage of the breast meat of broilers fed a diet supplemented with HS was observed in the final meat quality, which was positively affected by increased protein and decreased fat content. Because of its nutritional composition, it can be considered to be rather a valuable type of meat in human nutrition than ordinarily.

Gamma-linolenic acid (GLA) is a fatty acid from the ω-6 family. It is able to deliver a wide range of health benefits arising from its anti-inflammatory effects. An insufficient supply of GLA from agricultural and animal sources resulted in the development of a fermentation technique using lower filamentous fungi, which have the ability to accumulate high concentrations of GLA and beta-carotene during solid-state fermentation of cereals. The goal of this study was to observe the influence of the addition of prefermented cereal product, containing high amounts of GLA and beta-carotene, into the feed of broiler chickens on their immune status, and also the number of lactic acid bacteria and enterobacteria in gut content, which has never been studied before. Immunostimulation in the GLA group was manifested by a significant increase in the oxidative burst of phagocytes, CD4+CD8- lymphocytes in blood, and the CD4: CD8 ratio. Upregulation of gene expression for IgA in the GLA group indicates that the B-lymphocytes were stimulated at a local gut level. In the caecum, increased mRNA expression for mucin-2 and insulin-like growth factor was observed in the GLA group, which could contribute mainly to the protection of the intestinal mucosa and to better growth and regeneration of skeletal muscles. Improved immune activation and protection of the intestinal mucosa were subsequently reflected in a change of the microbial composition in gut contents; a significant reduction of enterobacteria occurred after GLA administration. We can conclude that prefermented cereals containing fungal GLA and beta-carotene represent a low-cost supplement for broiler diet having a beneficial health effect.

The aim of this work was to analyse the effect of addition of 10% (w/w) fermented bioproduct into commercial broiler feed on fatty acid profile, lipid oxidative stability, and sensory properties of chicken breast meat. The fermented bioproduct was prepared by fermentation of cornmeal by filamentous fungi Umbelopsis isabellina CCF 2412 in solid-state fermentation (SSF) process and the final bioproduct was enriched with gamma-linolenic acid and beta-carotene. In the experiment, 80 pieces of 1-day-old chickens COBB 500 were used. Half of them (control group) were fed only with commercial feed. Chickens of the experimental group were fed with commercial feed, and, from the 11th day of age until the time of slaughter (39th day), 10% of commercial feed was replaced with fermented bioproduct. Application of fermented bioproduct into commercial feed mixture positively influenced profile of fatty acids in breast meat. The amount of gamma-linolenic, alpha-linolenic, and oleic acids in fat of breast muscles was increased and n-6/n-3 ratio was significantly decreased. Profile and content of PUFAs did not change after thermal treatment of meat. Oxidative stability of fat and sensory properties of the meat during the storage (4°C, 7 days) of meat were not affected by fermented bioproduct.