Effects of monensin on protein supplements on performance, ruminal fermentation, degradability a Brachiaria decumbens and methane production in cattle

Author(s)

Gabriela Benetel

• Document type: Master's Dissertation
• Press: Pirassununga.
• Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
• Defense date: 2014-02-26

Examining board members

Marcus Antonio Zanetti; Raul Franzolin Neto; Luiz Carlos Roma Junior

• Advisor: Marcus Antonio Zanetti

Abstract

The aim of this research was to evaluate the inclusion of high monensin levels on protein supplements for cattle on (i) performance, (ii) fermentation and ruminal degradability and (iii) production of methane. To this end, three different experiments were performed. The experiments are presented in the chapters form. The introduction and literature review are presented in Chapter I and II. In Chapter III (performance): 64 cattle were randomly assigned to four treatments: control, containing protein supplement and control plus three monensin levels (400, 800 or 1200 mg/kg of supplement). The animals remained in four paddocks of Brachiaria decumbens where they were undergo weekly casters. Pasture samples were collected to determination of qualitative and quantitative variables. The average supplement intake, individual supplement intake and daily weight gain were estimated. The increased monensin levels decreased the supplement consumption and the animal performance. In Chapter IV (fermentation and ruminal degradability), four male cattle with rumen cannula were utilized in a Latin Square assay design 4x4, during 84 days. The animals were fed with Brachiaria decumbens, protein supplement of low consumption (500g/animal /day) and monensina. The treatments were 0, 200, 400 and 600 mg of monensin/day. The ruminal parameters evaluated were: production of short chain fatty acids (SCFA), ammonia concentration, pH, dry matter intake, in situ degradability of DM and ADF. The values found for ruminal fermentation and degradability of DM were not affected by treatments. Increased levels of monensin decreases linearly dry matter intake and the ADF degradability. In Chapter V (production of methane), four monensin levels were tested in vitro gas production. The objectives were to evaluate the fermentation kinetics, short chain fatty acids production, dry matter degradation and methane production. For this purpose, B. decumbens hay and protein supplement low consumption were used as substrate. An average supplement intake 500g/animal/day with levels of monensin (0, 200, 400 and 600 mg) was simulated. Gas samples were collected for measurement of methane production in 24hrs of incubation. The dry matter degradability and production of short chain fatty acids were determined after 24 and 96 hours of incubation. The potential gas production decreased as increased of monensin. The colonization time of the samples increased with monensin. No differences were observed in the degradability of dry matter and in the methane and SCFA production between treatments. (AU)

• FAPESP's process: 11/04674-0 - Inclusion of different monensin levels in supplements for beef cattle, and effect on weight gain, ruminal fermentation,ruminal degradability, total digestibility rate and methane in the rumen
• Grantee: Gabriela Benetel
• Support Opportunities: Scholarships in Brazil - Master