Development and Evaluation of a Commercial Direct-Fed Microbial (Zymospore®) on the Fecal Microbiome and Growth Performance of Broiler Chickens under Experimental Challenge Conditions.

Direct-fed microbials (DFM) are added to broiler chicken diets in order to promote the proliferation of beneficial intestinal bacterial populations, which may lead to gains in performance efficiency and, potentially, reduce the level of enteric pathogens in the broiler chickens. The selection and laboratory evaluation of Bacillus subtilis strains as well as the experimental trial results of a novel Bacillus-based commercial DFM product are described. Fifteen wild-type Bacillus subtilis strains were characterized and assayed for their enzyme production capability, spore resistance to pH, salinity, and temperature, and ability to inhibit the growth of E. coli and Salmonella spp. The final DFM formulation was evaluated and compared to an antibiotic growth promoter (AGPs) in two experimental trials. In Experiment 1, broilers were given a defined challenge of Eimeria spp. and Clostridium perfringens to induce intestinal dysbiosis. The optimal dose of the DFM was determined to be 0.3 kg/ton of feed. At this dose, the broilers fed the DFM performed as well as the Flavomycin®-fed broilers. Further, intestinal microbiome analysis indicates that the use of the DFM enhances bacterial diversity of the gut flora by day 5 of age, increasing levels of lactic acid bacteria (LAB) and Clostridiales by 25 days of age, which may enhance the digestion of feed and promote growth of the birds. In Experiment 2, the broilers were raised on recycled litter and given an undefined challenge orally to mimic commercial growth conditions. In this trial, the DFM performed as well as the bacitracin methylene disalicylate (BMD)-11%-fed birds. The results of the present studies suggest that this novel DFM, Zymospore®, improves the performance of broiler chickens under experimental challenge conditions as effective as an AGP, providing a safe and effective substitute to the poultry industry.

Laying hens fed mycotoxin-contaminated feed produced by Fusarium fungi (T-2 toxin and fumonisin B1) and Saccharomyces cerevisiae lysate: Impacts on poultry health, productive efficiency, and egg quality.

Mycotoxins represent substantial challenges to the farming industry. These include toxins produced by Fusarium fungi, particularly trichothecenes (toxin T-2) and fumonisin (FB1). In the present study, we determined the effects of addition on Saccharomyces cerevisiae lysate (SCL) added to feed contaminated with T-2 and FB1 in terms of health, productive efficiency, and egg laying quality. We used 60 Hy-line Brown laying hens, and divided them into five groups with four repetitions per group and three birds per repetition. There was one group with no contamination with toxin (NoC). The four other groups included combinations of mycotoxin (4 ppm T-2, and 20 ppm FB1): A contamination group was used as control (the C+ group), and another two contained 500 g/ton of SCL (Detoxa Plus®) (the C + D500 group) or 1000 g/ton of SCL (the C + D1000 group). Finally, one group received feed containing 500 g/ton of Detoxa Plus® and 1000 g/ton of Uniwall® MOS 25 (the C + D500 + U1000 group). The experimental period was 84 days, divided into three productive cycles of 28 days each. The NoC hens had greater egg production than the other groups. Hens that consumed feed with SCL had greater egg production than did the C+ group. The NoC hens produced eggs with greater weights than did the C hens; however, C + D1000 and C + D500 + U1000 birds produced greater egg weights than did the C+ group. The C+ group produced lower egg masses than did the NoC and C + D500 + U1000 groups. The feed intake (FI) was lower in hens that ingested mycotoxin. The use of SCL in feed minimized the negative effects of mycotoxin on feed conversion ratio (FI/dozen). Effects of treatment were detected for feed conversion ratio (kg/kg). The hens that consumed mycotoxin had lower shell resistance and thickness compared to those in the NoC group. The red color of egg yolk was greater in the control groups. There were fluctuations in levels of liver enzymes when birds consumed mycotoxin (sometimes reduced and sometimes increased); nevertheless, the cumulative effect increased the activity of alanine aminotransferase. The serum concentration of reactive oxygen species was greater in hens that ingested mycotoxin only on d 84 compared to the NoC group. Serum glutathione S-transferase activity was greater on d 56 in C + D500 and C + D1000 hens than in the others. We conclude that, in general, the consumption of mycotoxin impaired the performance and quality of the eggs of the hens; the addition of the S. cerevisiae lysate and the addition organic acids, yeast cell wall and mineral carrier minimized some of the negative effects caused by T-2 and FB1.

Comportamento de células do sistema imune frente ao desafio com Salmonella Enteritidis em aves tratadas e não tratadas com ácidos orgânicos / Behavior of cells of immune system to the challenge with Salmonella Enteritidis in birds treated and untreated with organic acids

A Salmonelose é uma importante zoonose, considerada a principal causa de infecções bacterianas, sendo associada ao consumo de produtos avícolas. Como alternativa de controle, ácidos orgânicos têm sido amplamente usados. No entanto, pouco se conhece sobre o estado imunológico de aves de produção, e uma avaliação deste status é necessária para proteger frente a enfermidades e para garantir à aplicação segura de agentes terapêuticos ou imunização profilática. Este trabalho teve como objetivo verificar o comportamento do sistema imunológico das aves previamente infectadas com Salmonella Enteritidis (SE) tratadas com um composto de ácidos orgânicos em diferentes concentrações administrado via água e ração comparando com as aves infectadas e não tratadas. Foram inoculados 120 frangos de corte com 1mL de SE, via oral, na concentração de 1,0 x 108 UFC/mL, no 1º e 2º dia de idade, divididos em seis tratamentos com duas repetições, utilizando 200, 400, 500 e 1000ppm do ácido orgânico. Aos 35 dias de vida das aves, foram coletados, de todos os grupos, alíquotas de sangue de 3mL em tubo contendo EDTA para a avaliação das células imunes através de citometria de fluxo. Foram analisadas as porcentagens circulantes de células CD4+, CD8β+, MHC I+, MHC II+, TCRVβ1+, TCRVβ2+ e CD28+. Para análise microbiológica foram coletadas tonsilas cecais destas aves. Observou-se com esse estudo que os ácidos orgânicos nas dosagens 1000ppm na água e 500ppm na ração durante, dois e sete dias respectivamente antes do abate, foram eficazes na redução da infecção por SE em frangos de corte, comprovadas pelo método microbiológico e demonstradas através do comportamento das células do sistema imune. No presente estudo as aves infectadas apresentaram uma proporção menor de células T auxiliares circulantes quando comparadas às aves infectadas, mas tratadas com o AO ou com o grupo não infectado. A mesma tendência pode ser observada para as células CD28+, TCRVβ1+ e MHC IIbright+, e, com menor resolução, para CD8β+.

Salmonellosis is an important zoonosis, considered the leading cause of bacterial infections, and is associated with the consumption of poultry products. As alternative control, organic acids have been widely used. However, little is known about the immune status of poultry production, and an evaluation of this status is necessary to protect against disease and to ensure the safe application of therapeutic agents or prophylactic vaccination. This study aimed to verify the behavior of the immune system of birds previously infected with Salmonella Enteritidis (SE) treated with a compound of organic acids in different concentrations administered via water and food, compared with the infected birds and untreated. One hundred and twenty broilers were orally inoculated with 1ml of SE at a concentration of 1.0x108 CFU/mL, at 1 and 2-days-old and divided into six treatments with two repetitions of 200, 400, 500 and 1000ppm organic acid. From 35-days-old birds of all groups were collected aliquots of 3mL of blood into a tube containing EDTA for the evaluation of immune cells by flow cytometry. We then analyzed the percentages of circulating CD4+, CD8β+, MHC I+ MHC II+, TCRVβ1+, CD28+ + and TCRVβ2. For microbiological analysis were collected caecal tonsils of these birds. We found that organic acids in dosages 1000ppm 500ppm in water and in feed for 2 to 7 days before slaughter, respectively, were effective in reducing SE infection in broilers, proven by microbiological method and demonstrated through the behavior of immune cells. The infected birds showed a lower proportion of circulating T helper cells compared with infected poultry, but treated with AO or with the uninfected group. The same trend can be observed for CD28+ cells, and MHC IIbright+ TCRVβ 1+, and with lower resolution, for CD8β+.