Effect of fungal gamma-linolenic acid and beta-carotene containing prefermented feed on immunity and gut of broiler chicken.

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.

Detection of maduramycin residues in the tissues of chickens and pheasants by the screening test for antibiotic residues (STAR).

Maduramycin is a coccidiostat authorized as a feed additive in poultry. Council Directive 96/23/EC stipulates that monitoring of foods of animal origin for residues of coccidiostats is mandatory. The aim of the present study was to evaluate the STAR for the screening of maduramycin residues in the tissues of broiler chickens and pheasants. Both animal species were supplied feed medicated with Cygro l% premix according to recommendations for use (5 mg kg(-1) of complete feed). The residues were investigated for a period of 7 days: day 0 (the last day of the administration of maduramycin), days 1-5 (the days of the withdrawal period) and day 6 (the first day after elapse of the withdrawal period). According to STAR the positivity of the sample (the presence of residues of antibacterial substances) is indicated by a zone of inhibition exceeding 2 or 4 mm in width, depending on the test organism. Maduramycin residues were detected only on the plates seeded with the test organism Bacillus stearothermophilus var. calidolactis ATCC 10149. The results showed that there was higher potential for the presence of maduramycin residues in broiler chickens than in pheasants. All chicken tissues (muscle/thigh and breast/gizzard, liver, heart, kidneys, spleen, lungs) were positive for maduramycin (inhibition zones ≥4 mm) not only throughout the withdrawal period, but also even 5 days after elapse of the withdrawal period. In the case of pheasants the positive results were detected in the gizzard, liver, heart, kidneys, spleen and lungs. On day 5 of the withdrawal period no positive results were detected; however, on day 6 the heart and spleen were positive again.