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.

Correlation between intestinal health and coccidiosis prevalence in broilers in Brazilian agroindustries.

Coccidiosis is caused by protozoa of the genus Eimeria. These are intracellular parasites of enterocytes that rupture the host cell, causing lesions in the intestinal mucosa. The lesions caused by Eimeria reduce nutrient absorption capacity, negatively affecting productive gains in broilers, and representing a gateway for other enteropathogens. The objective of this study was to analyze the correlation between lesions caused by Eimeria and the prevalence of coccidiosis and other alterations found in the gastrointestinal tracts of broilers produced in Brazil from 2017 to 2018. Intestinal health evaluations were performed in 32 integrations (farm) of broilers in Brazil, totaling 726 birds analyzed between the ages of 22 and 40 days. Necropsied chickens were collected at three different points, with at least three birds per shed. We analyzed the following changes in the gastrointestinal tract: presence of cellular desquamation, fluid and mucus excess, ingestion of bedding, small and large intestine lesion, food passage, altered tone, "Turkish towel" lesions, worm infection, enteritis and gizzard erosion. The definition of macroscopic lesion scores caused by Eimeria acervulina, Eimeria maxima, Eimeria tenella followed a specific methodology. Mucosal oocyst counts for E. maxima (E. maxima micro) was performed using an optical microscope with a magnification of 100×. We found that the species E. acervulina had the highest prevalence (5.5%). With respect to E. acervulina, a positive correlation was observed with cellular desquamation, bedding ingestion and passage of food. The second highest prevalence was E. maxima (average of 4%), showing positive correlations with cellular desquamation, fluid excess, bed ingestion, feed passage and E. acervulina. E. tenella represented the lowest prevalence (0.8%) among the species of Eimeria analyzed, showing a positive correlation with altered intestinal tone. On microscopic evaluation, E. maxima was present in 45% of mucosa scrapings, representing subclinical coccidiosis of 1125% (11.25-fold) greater than the rate of clinical coccidiosis. Regarding other alterations that were visualized in the gastrointestinal tract, we have recorded the incidence of altered intestinal tone (0.1%), worm infection (0.4%), small intestine (0.8%), enteritis (1%), duodenitis (1.5%), "Turkish towel" lesions (3.3%), excess fluid (4.5%), bed ingestion (6.9%), excess mucus (8.4%), food passage (10.3%), cellular desquamation (11%) and gizzard erosion (13.4%). We conclude that monitoring is of paramount importance to understand the intestinal health status of poultry lots. Microscopic E. maxima is present in 45%. We identified factors that correlate with reduction in intestinal health, impairing zoo-economic performance.