Immunomodulatory Effects of Natural Feed Additives for Meat Chickens.

Broiler chickens are increasingly kept in large numbers in intensive housing conditions that are stressful, potentially depleting the immune system. With the prohibition of the use of antibiotics in poultry feed spreading worldwide, it is necessary to consider the role of natural feed additives and antibiotic alternatives to stimulate the chickens' immune systems. We review the literature to describe phytogenic feed additives that have immunomodulatory benefits in broilers. We initially review the major active ingredients from plants, particularly flavonoids, resveratrol and humic acid, and then describe the major herbs, spices, and other plants and their byproducts that have immunomodulatory effects. The research reviewed demonstrates the effectiveness of many natural feed additives in improving the avian immune system and therefore broiler health. However, some, and perhaps all, additives have the potential to reduce immunocompetence if given in excessive amounts. Sometimes additives are more effective when given in combination. There is an urgent need to determine tolerance levels and optimum doses for additives deemed most suitable to replace antibiotics in the diet of broiler chickens. Effective replacement is most likely with readily available additives, such as olive oil byproducts, olive leaves and alfalfa. It is concluded that effective replacement of antibiotic function with plant-derived additives will be possible, but that further research is necessary to determine optimum doses.

Biomedical evaluation of antioxidant properties of lamb meat enriched with iodine and selenium.

The article presents a study of the antioxidant properties of meat from lambs that received organic forms of iodine and selenium during growth. This meat was included in diets of laboratory animals using a model of acute toxic hepatitis. The experiments resulted in developing and testing a technique that was effective in enriching lamb with bioorganic elements of iodine and selenium and contributed to the activation metabolism in the bodies of animals consuming the meat. The purpose of the presented investigation was to compare the roles of bioorganic iodine and selenium and their combination as antioxidants in rat rations using a model of acute toxic hepatitis induced by carbon tetrachloride. The experimental studies have established a hepatoprotective effect of lamb meat enriched with selenium and iodine on rats suffering from toxic xenobiotic effects. This was confirmed by normalized hematological and biochemical measures in the blood of the experimental rats.

Probiotic Intake Increases the Expression of Vitellogenin Genes in Laying Hens.

A promising approach for slowing down the rate of reproductive aging is the use of probiotic bacteria as a feed additive. In the current study was investigated the influence of the intake of a potential probiotic on the follicle content and expression of vitellogenin genes (vtg1, vtg2, vtg3) in aged hens. RNA was isolated from liver samples collected from 570-day-old laying hens and gene expression levels were measured using RT-PCR. Bacillus subtilis KATMIRA1933 supplementation had a positive effect on the number of formed follicles in hens and also triggered a significant increase in the relative expression levels of vtg1, vtg2, and vtg3. A Bacillus amyloliquefaciens B-1895 enriched diet or a combination of the two strains had a modest effect on both the number of follicles and the expression of vitellogenin genes. Additionally, the study demonstrates that vitellogenin mRNA expression levels can be considered as a biomarker in a convenient approach for analyzing the hen's egg-laying ability.

The Impact of Bacillus subtilis KATMIRA1933 Supplementation on Telomere Length and Mitochondrial DNA Damage of Laying Hens.

In the current study, we performed in vivo investigation of probiotic intake influence on nuclear and mitochondrial DNA damage of hens, using quantitative PCR techniques. The probiotic supplementation to the diet of Hisex Brown hens had no significant effect on the rate of telomere shortening. After prolonged probiotic intake (225 and 445 days), the 18-21% decrease in the mtDNA lesions was detected. Since avian mitochondrial DNA damage investigations are rare, the current study of the probiotic-enriched diet's impact on the damage of the hen mitochondrial DNA is novel and highly important. The decrease of mtDNA damage is a beneficial property, which could positively affect the reproductive aging of hens. The positive impact of probiotic supplementation on hens' performance traits such as hen-day egg production, egg weight and mass, and feed conversion ratio was observed.

Bacillus Probiotic Supplementations Improve Laying Performance, Egg Quality, Hatching of Laying Hens, and Sperm Quality of Roosters.

The study aims at elucidating the effect of bacilli probiotic preparations on the physiology of laying hens and roosters. Probiotic formulations were prepared as soybean products fermented by Bacillus subtilis KATMIRA1933 and Bacillus amyloliquefaciens B-1895. In this study, groups of male and female chickens were used. These groups received a probiotic preparation based on either B. subtilis KATMIRA1933 or B. amyloliquefaciens B-1895, or of a mixture of strains, from the first day to the age of 39 weeks. These preparations positively affected egg production, quality of sperm production, and quality and hatchery of eggs. Considering the simplicity and cost effectiveness of the soy-based probiotic preparation, these formulations should be considered as advantageous in modern livestock production.