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.

No abstract

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.

No abstract

The study compared the effect of dietary supplementation with an inorganic or organic source of zinc (Zn) on mucin 2 (MUC-2) and IgA gene expression, the cytokines IL-17 and TGF-β4 and the secretory IgA content (sIgA) in broiler jejunum. One-day-old chickens were fed an unsupplemented basal diet (BD) or the same BD supplemented with 30 or 70 mg/kg of added Zn from ZnSO 4 ·H 2 O or Zn chelate of glycine hydrate for 40 days. The highly expressed MUC-2 and IgA genes were observed in both groups supplemented with the low-dose Zn sources (30 mg/kg). A higher sIgA concentration was observed in both the ZnSO 4 groups and the glycine-zinc/30 mg group. Our data indicate that the organic Zn chelate has better availability than the inorganic Zn source, and the low-dose Zn diets proved to be more beneficial to the maintenance of intestinal immune homeostasis. ARTICLE HISTORY