Effect of experimental periods on the parcial and total digestion in cattle fed two levels of forage

[摘要] - The objective of this research was to evaluate the effects of two experimental periods and two forage levels in the diet on the total and parcial apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), gross energy (GE) and starch. Four Holstein steers, averaging two years old and 340 kg of body weight, ruminally and duodenally cannulated, were used. The experimental design was a 4 x 4 latin square and the animals received four treatments as following: two forage levels (30 and 70%) and two experimental periods (14 and 21 days). There was effect of forage level on intestinal and total digestibility of DM, OM, CP and starch and on total digestibility of GE. There was effect of forage level on ruminal digestibility of ADF and NDF. There was no effect of experimental periods on the digestibility coefficients of the nutrients. It was concluded that 14 days experimental period is practible when hay is used.

[学科分类] 兽医学

[关键词] digestibility;experimental period;forage level   IntroduçãoA digestão em ruminantes é o resultado de uma seqüência de processos que ocorrem em diferentes segmentos do trato digestivo e incluem a fermentação dos componentes dietéticos pelos microrganismos do rúmen-retículo;a hidrólise ácida e a degradação enzimática no abomaso e intestino delgado do animal hospedeiro e a fermentação secundária no intestino grosso (SIGNORETTI et al