Browsing by Subject "probiotic"
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Item Effect of Phytate-Degrading Probiotics on Broiler Performance(2013-10-30) Askelson, Tyler EProbiotics have been demonstrated to promote growth, stimulate immune responses, and improve the microbial food safety of poultry. While widely used, their effectiveness is mixed and the mechanisms through which they contribute to poultry production are not well understood. Phytases isolated from microorganisms are increasingly supplemented in feed to improve digestibility and reduce anti-nutritive effects of phytate. The microbial origin of these enzymes suggests a potentially important mechanism of probiotic functionality. Our objective was to investigate phytate degradation as a novel probiotic mechanism using recombinant Lactobacillus cultures expressing Bacillus subtilis phytase. B. subtilis phyA was codon optimized for expression in Lactobacillus and cloned into the expression vector, pTRK882. The resulting plasmid, pTD003, was transformed into Lactobacillus acidophilus, Lactobacillus gallinarum, and Lactobacillus gasseri. SDS-PAGE revealed an approximately 44 kDa protein in the culture supernatants of Lactobacillus pTD003 transformants corresponding to the predicted molecular weight of B. subtilis phytase. The phytate degrading ability of these cultures was evaluated by determining the amount of inorganic phosphate released from sodium phytate. Expression of B. subtilis phytase increased phytate degradation of L. acidophilus, L. gasseri, and L. gallinarum approximately 4-, 10-, and 18-fold over the background activity of empty vector transformants. The effect of administration of recombinant phytase-expressing L. gallinarum and L. gasseri was evaluated in broiler chicks fed a phosphorous deficient diet (0.25% aP). Phytase-expressing L. gasseri improved weight gain (P < 0.05) of broiler chickens to a level comparable to chickens fed a phosphorous adequate control diet (0.40% aP) demonstrating proof of-principle that administration of phytate-degrading probiotic cultures can improve performance of livestock animals. Additionally, this will inform future studies investigating whether probiotic cultures are able to combine the performance benefits of feed enzymes with the animal health and food safety benefits traditionally associated with probiotics.Item Preventive Measures to Control Clostridial Outbreaks of Gangrenous Dermatitis in Commercial Broiler Operations(2011-08-08) Waneck, Casey R.Gangrenous dermatitis (GD) has become a major health problem among broiler flocks in the United States, resulting in high mortality, carcass condemnations, and trimmed parts. There are large economic losses due to GD. Clostridium septicum, Clostridium perfringens type A, and Staphylococcus aureus are the etiologic agents associated with GD. Gangrenous dermatitis has been associated with birds that have a compromised immune system. It is known that the gastrointestinal (GI) tract plays a crucial role in animal health and performance. The development of a healthy normal microflora in the GI tract benefits the host by improved resistance to pathogens. Our hypothesis is the application of commercial disinfectants, probiotics, vitamins, acidifiers, and windrowing technologies will reduce Clostridium levels in poultry operations. The objective of the first study was to administer probiotics to commercial broilers on three farms periodically throughout the grow-out cycle to conclude if bird health and performance was improved. The objective of the second study was to use commercial disinfectants, vitamins, acidifiers, and windrowing technologies on three farms in multiple houses and determine their effects on broiler production parameters. During grow-out, standard production practices were followed in all experiments and standard production parameters were measured. On all three farms in this study, the probiotic-treated houses had no mortality due to GD and an increase (PItem The Effects of Probiotic and Eimeria on Gut Morphology and Humoral Immunity in Broilers(2012-02-14) Horrocks, Sadie LynCoccidiosis has a negative economic impact on the commercial poultry industry, and probiotics are beneficial bacteria that aid in maintaining healthy gut microflora. We hypothesized that probiotic administration would positively affect gut morphology and increase IgG secretion during an Eimeria challenge, which was evaluated by measuring total chicken IgG and gut morphology (villus height, villus width, villus surface area, crypt depth, villus height to crypt depth ratio and lamina propria thickness). On day-of-hatch, broilers were placed into floor pens with 50 percent pine shavings and 50 percent used litter. The broilers were exposed to Eimeria oocysts via the feed on day 14 and challenged on day 36. On days 6, 22, 36, and 43, tissue samples from the intestine were collected for morphological evaluation, and blood samples were taken to quantify chicken IgG from serum. Data were measured using a factorial ANOVA and main effect means were deemed significant at P ? 0.05. In cases where significant interactions were observed, data was subjected to a one-way ANOVA. All means were separated using a Duncan?s Multiple Range Test. On day 6 in the duodenum, a significant interaction was observed regarding vaccination and probiotic administration (Coccivac?-B, Intervet/Schlering-Plough Animal Health/Merck and Co., Inc., Whitehouse Station, NJ). Villus height to crypt depth ratio decreased in ionophore treated birds compared to control birds in the duodenum and lower ileum on day 6, 36, and 43. Villus crypt depth in vaccinated birds decreased in the duodenum after the challenge. On day 43, the ionophore treated birds had less villus height and surface area compared to control and vaccinated birds, while lamina propria thickness increased in the duodenum, and non probiotic birds had longer villi than probiotic birds. On day 22, vaccinated birds had significantly increased chicken IgG levels compared to the control and ionophore birds, and the non probiotic birds had significantly increased IgG secretion compared to probiotic fed birds. On day 36, the ionophore birds had significantly increased levels of IgG compared to the control birds, which could also support that the ionophore delayed exposure to the parasite. These results suggest that gut morphology and humoral immunity are affected by probiotic administration, coccidiosis vaccination, ionophore application and Eimeria challenge. Both the day 43 morphology results and day 36 chicken IgG results for the ionophore treated birds demonstrates that ionophore administration delays exposure of the avian gut to invasive coccidia. More research is necessary to evaluate how probiotics influence coccidiosis vaccination and humoral immunity, so that probiotics may be used to improve the effectiveness of coccidiosis vaccination and to evaluate if probiotics aid in ameliorating the effects of an Eimeria infection.