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| Author(s): |
Bruna Gomes Alves
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2016-03-30 |
| Examining board members: |
Marcos Veiga dos Santos;
Ives Cláudio da Silva Bueno;
Luiz Alberto Beraldo de Moraes
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| Advisor: | Marcos Veiga dos Santos |
| Abstract | |
Actinobacteria are microorganisms that can produce bioactive compounds present in crude extracts with antibiotic and ionophore activity. Our hypothesis was that actinobacteria crude extracts showed similar efficacy to monensin on ruminal fermentation; increasing the digestibility of dry matter and organic matter, increasing propionate concentration and reducing the total gas production, protein deamination and methane. Therefore, the objective was to evaluate two crude extracts (AMC and Caat) on in vitro ruminal fermentation (total gas, short chain fatty acids (SCFA) and methane (CH4) production; in vitro digestibility of dry matter (IVDDM), of organic matter (IVOMD) and ammonia nitrogen production (NH3-N). The study was divided into two phases: the first aimed to establish the dose-response curve of the extracts and the second aimed to evaluate a positive monensin control. For both, it was used three lactating Holstein cows with ruminal fistula as rumen fluid donors (inoculum). The diets were based on corn silage, soybean meal, urea, ground corn and mineral supplement under forage:concentrate ratio of 60:40. Ruminal fluid samples were collected by a vacuum pump, stored in bottles and coolers and transported to the laboratory for incubation in glass bottles. For the first phase, they were evaluated 4 doses (0.3; 0.6; 0.9 and 1.20 mg) of 2 extracts (AMC and Caat) on a 72 hours in vitro assay, which were measured gas production during incubation and in the end, SCFA, IVDMD and IVOMD concentrations were determined. In the second phase, it was a 24 hours assay, and include final analyzes for CH4 and NH3-N, plus SCFA, IVDMD, IVOMD and gas production. The experimental design was completely randomized (DIC) for both phases. In the first phase, the Caat inclusion linearly decreased IVOMD after 72 hours and reduced isovaleric acid and butyric acid concentration and acetate:propionate ratio and cumulative gas production by 24, 48 and 72 h. In the second stage, the inclusion of the extracts caused a reduction of the cumulative gas production in 24 hours, being lower in monensin and Caat treatments. There was an effect of Caat and monensin inclusion on SCFA concentration, increasing the propionate concentration and reducing the butyrate and acetate concentration and the acetate: propionate ratio. The NH3-N concentration was lower by Caat inclusion and monensin while the CH4 concentration was higher for the extracts inclusion as compared with monensin, however were not bigger than control. The Caat inclusion was able to modify the in vitro fermentation similarly to monensin, but did not affect the fiber digestibility. Moreover, AMC did not affect the rumen fermentation, either in fiber digestibility, total gas, methane, ammonia nitrogen and SCFA production (AU) | |
| FAPESP's process: | 14/08905-5 - Effect on metabolites produced by actinomycetes on in vitro digestibility and ruminal fermentation |
| Grantee: | Bruna Gomes Alves |
| Support Opportunities: | Scholarships in Brazil - Master |