Salive effect on the chemical composition of forages obtained with oesophageal fistula

Abstract

The effect of the saliva on the chemical composition of grass samples obtained with steers fitted with oesophageal fistula was studied. The following grasses were used for stall trials: Melinis minutiflora and Pennisetum purpureum; and for field trials, mixed pasture of Melinis minutiflora, Paspalum sp. and Paspalum notatum were used. When the crude protein (PB) level of the grass varied between 5 and 8%, the content in the fistula sample increased or stayed similar. When the level was between 12 and 16% in the grass, the protein content in the fistula samples decreased. The level of acid detergent fiber (ADF) decreased in the fistula samples. The ash and phosphorus levels significantly increased in fistula samples, while the calcium level did not change. In the field trials, the results had the same trend as those of the stall trials. The exceptions were the ADF content that increased, and calcium content that decreased in the fistula samples. Squeezing the fistula samples decreased the crude protein, ash and phosphorus contents, but did not change the calcium content, and increased the ADF.