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| Author(s): |
Johnny Maciel de Souza
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Pirassununga. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2019-08-09 |
| Examining board members: |
Augusto Hauber Gameiro;
Ives Cláudio da Silva Bueno;
Danilo Domingues Millen;
Paulo Henrique Mazza Rodrigues;
Tiago Antônio Del Valle
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| Advisor: | Júlio César de Carvalho Balieiro; Francisco Palma Rennó |
| Abstract | |
This study aimed to evaluate the effects of supplementation with live cultures of Aspergillus oryzae and fibrolytic enzyme on fiber digestibility, kinetics and rumen ecosystem of lactating cows. Experiment 1: the chemical composition and fermentative profile of silages inoculated with doses of fibrolytic enzymes (0, 1,3 e 2,6g/kg MS, Fibrozime®, Alltech) at ensiling of sugarcane varieties and corn, in different ensilage periods (30, 60 e 120d), was evaluated. The design was completely randomized (CRD), with 27 treatments and 3 repetitions by treatment. The inclusion of fibrolytic enzyme, as well as increased silage time, promoted the increase of NDF and ADF contents, and the reduction of NDF digestibility of sugarcane silages, accompanied by increased losses of DM by effluents and reduction of dry matter recovery, with no effect on corn silage. Experiment 2: the objective was to evaluate the in vitro digestibility of DM and NDF by fermentative kinetics and in vitro gas production of roughage (corn and sugarcane silage) in response to the addition of live cultures doses of A. oryzae (0, 1, 3 and 5g/100ml) or doses of fibrolytic enzyme (0, 8, 16 and 24g/100ml), or the combination of both. The design was completely randomized (CRD), with 36 treatments and 3 repetitions by treatment. The inclusion of A. oryzae increased IVDNDF and IVDDM, regardless of the roughage. The higher dose of the fungus increased the potential gas production in sugarcane silage. The fibrolytic enzyme elevated IVDNDF and IVDDM only in corn silage, increased the final volume of gases and reduced colonization time, regardless of the dose. Experiment 3: in order to quantify the effect of the inclusion of A. oryzae (5g/animal/d), fibrolytic enzyme (24g/animal/d) and combination of both on DM intake, digestion rate and ruminal passage of NDF, ruminal fermentation, and population composition of ruminal bacteria, eight ruminalcannulated Holstein cows were used. The experimental diets was composed of 61% roughage in DM, containing corn silage. The design was two contemporary 4x4 Latin squares, with 4 treatments and 8 repetitions per treatment. The additives increased the consumption of DM and NDF potentially degradable fraction in comparison to the control. There was no effect on milk production, but treatment with the fungus raised the milk fat content. A. oryzae and its combination with fibrolytic enzyme increased the ruminal acetate concentration, and increased ruminal digestibility of NDF and pdNDF. An increase in the ruminal digestion rate of NDF was observed in treatments with fungus and the combination with fibrolytic enzyme. The additives had the potential to modulate the ruminal fermentation, where the combination of the fungus with the enzyme presented positive results on the ruminal digestibility parameters of the fiber. (AU) | |
| FAPESP's process: | 17/11537-6 - Supplementation with live cultures of Aspergillus oryzae and fibrolytic enzyme for dairy cattle: Effects on metabolism, kinetics and rumen ecosystem |
| Grantee: | Johnny Maciel de Souza |
| Support Opportunities: | Scholarships in Brazil - Doctorate |