Fibra fisicamente efetiva e parâmetros fecais em confinamentos de bovinos de corte

• Ano de defesa: 2019
• Autor(a) principal: Gabriel Santos Persiquini Cunha
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Bovinos de corte; pH fecal; Tamanho de partícula; Amido; Bovino de corte; Bovino de corte Nutrição
• Link de acesso: http://hdl.handle.net/1843/ICAS-BDWPCA

The objective of this study was to evaluate the particle size and the physically effective fiber content (peNDF) of total diets and their effects on the fecal parameters of beef cattle in commercial feedlots. Genetic group (GG), animal category, and total diet and fecal samples were collected from 15 commercial feedlots. The diets were separated using the sieve Penn State Particle Size Separator (PSPS), with diameters of 19, 8 and 4 mm of porosity and a bottom box, which were subsequently analyzed. The feedlots were categorized into two treatments: peNDF <20% and peNDF 20%. In feces samples, the score, pH, and starch fecal, were evaluated. The evaluated characteristics were submitted to analysis of variance, with the aid of the procedure PROC MIXED of the SAS (2004) using the animal as experimental unit for the characteristics of fecal parameters and batch sampled for the characteristics of the diets. The particles retained in the 19 mm sieve and NDF of the diet were similar to each other when compared to the two groups of peNDF (P> 0.05). The percentage of particles retained in all sieves was altered by dietary peNDF (P <0.05) and a positive correlation (P <0.05) was observed between particles larger than 4 mm and peNDF. The contents of DM, CP, EE and dietary starch were altered by the treatment (P <0.05). In addition, a negative correlation (P <0.05) between dietary starch and peNDF was observed, that is, diets with lower effectiveness present higher starch content in the diet. Results of scoring, pH and chemical analysis of feces were not influenced by the treatments (P> 0.05), except for fecal DM that was higher in the diet with peNDF <20%. Therefore, diets with more than 20% of peNDF presented higher particle size, lower starch content in the total diet and consequently lower fecal DM. The values used as reference for peNDF in beef cattle are data obtained by experimentation in dairy cows using the 1.18mm sieve. Therefore, it is necessary to carry out new works, evaluating other variables that were not addressed here, to determine more accurately the recommendations of peNDF for beef cattle.