Cana de açúcar tratada ou não com óxido de cálcio na alimentação de fêmeas bovinas leiteiras

• Ano de defesa: 2010
• Autor(a) principal: Mariana Magalhães Campos
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; VET - DEPARTAMENTO DE ZOOTECNIA; Programa de Pós-Graduação em Zootecnia; UFMG
• Palavras-chave em Português: Bovino; Consumo; Digestibilidade; Hidrólise; Dieta Animal
• Link de acesso: http://hdl.handle.net/1843/31774

Sugarcane-based diets containing different levels (0%, 0.5%; 1.0% e 2.0% in as-fed diet) of calcium oxide (CaO) were offered to Holstein x Gyr lactating dairy heifers and cows. The addition of CaO, in different levels of inclusion, did not alterate EE, NDF, NDFap, ADF, Lig, Cel, HCel, CP and P content of the diet. However, as the levels of CaO were enhanced, the intake of the majority of nutrients (DMI, DMI%PV, OMI, OMI%PV, NDFI, NDFI%PV, NDFIap, NDFIap%PV, ADFI, LigI, CeIl, CPI, EEI, PI) were reduced. Converselly, enhancement of calcium intake was observed as the proportion of CaO in the diet was enhanced. Adding CaO to the diet caused reduction of DM, OM and ADF digestibility, but did not alterate NDF and NDFap digestibility. . The addition of CaO on diets enhanced the ruminal pH values. No differences were observed in the ruminal fluid N-NH3 concentration. The average ruminal acetate concentration were similar among diets, but the molar proportion of ruminal molar acetate were higher in animals treated with diets containing CaO. The average concentrations and the molar proportions of ruminal propionate were lower in animals fed with diets containing CaO. The average concentration of ruminal volatile fatty acids were similar among diets. The ruminal acetate:propionate ratio were higher for the treatments with CaO. The paramenters of solid phase flux dinamics were similar among diets, except for the cecal and colon passage rate, which was linearly enhanced as the percentage of CaO in the diet was enhanced. The liquid phase passage rate and the recycling rate were linearly enhanced as percentage of CaO in the diet was enhanced. The potential and effective degradability as well as the degradation rates of DM and OM were lineraly enhanced with the increasing of the CaO levels in diet. However, no differences of potential and effective degradability and on degradation rates of NDF and ADF were detected among treatments. The adition of CaO in sugarcane-based diets offered to Holstein x Gyr dairy cows reduces the percentage of protein, EE and DE in the milk, and depending on the percentage of addition, leads to reduction in milk yield. Alteration in intake behavior was not observed among treatments, as well as the distribution of activities considered for evaluation of this parameter. In conclusion, adding CaO (0.5 to 2.0% as-fed) in sugarcane-based diets offered to Holstein x Gyr lactating dairy heifers and cows. is not recommended.