Levels of degradable protein given to heifers for the ciliate protozoa concentration and other ruminal parameters

• Autor(a) principal: Nogueira Filho, José Carlos Machado
• Data de Publicação: 2008
• Outros Autores: Martin-Orúe, Susana Maria, Balcells, Joaquim, Fondevila, Manuel, Ablas, Denise de Souza
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Acta Scientiarum. Animal Sciences (Online)
• Texto Completo: https://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/2650
• topic: protozoários ciliados; novilhas Holstein; parâmetros ruminais; proteína degradável; 5.04.00.00-2 Zootecnia

In this experiment four Holstein heifers fitted with rumen and duodenum canulae were utilized to evaluate the rumen parameters as pH, passage rate (%/h), volume (L) and ciliated protozoa concentration, when fed diets with four levels of rumen degradable protein. This was achieved supplementing 0, 25, 50 or 75 grams of degradable protein per kg of concentrate as a urea and casein (98.2% OM and 93.2% CP). The diets had 25% of barley straw without treatment and 75% concentrate formulated to contain different proportions (25/75 and 75/25) of corn and barley and also 5% of wheat residue and 5% of mineral and vitamin supplement. A continuous infusion of Cr-EDTA was used as a liquid phase marker. A cross-over design with 8 treatments (2 diets and 4 degradable protein levels) were utilized in 8 balance periods in a factorial arrangement. The level of degradable protein significantly affected the mean pH values that decreased as the supplementation increased (P < 0.05) mainly in the corn based diet. The passage rate of the liquid phase, similar for the diets, was lower in the first experimental period (8.65 vs. 10.56%/h) and decreased as the level of degradable protein increased. Ciliated protozoa had higher concentration (P < 0.01) in the corn diet (79.1 x 103/mL) than in the barley diet (59.5 x 103/mL). The Entodinium genus represented 87.8% of the total population. The genus Epidinium showed lower values (P < 0.05) in the barley diet (3,73 vs. 1.89 x 103/mL) and in the second experimental period (4,40 vs. 1.25 x 103/mL). The estimates of total ciliated in the rumen were 26.6 vs. 22.1 x 103/mL, respectively for the corn and barley diets (P < 0.05). The ciliated species detected were typical of high concentrate diets.