Bacterial Protein Correction on In situ Digested Samples with Purine or NDF Methods
Keywords:
In situ ruminal digestion, bacterial protein, purine, neutral detergent fiber.Abstract
In situ ruminal digestion procedure is known procedure for estimating ruminal digestion. In situ procedure requires
correction for microbial contaminations, and the purine method has been used to correct microbial attachments. The
neutral detergent fiber (NDF) method has been proposed as an alternative to the purine method. Objectives of this
experiment were to compare purine and NDF method for microbial correction. Alfalfa hay, bermudagrass hay, tall fescue hay, corn and soybean meal samples were selected. Chemical analyses of dry matter (DM), crude protein (CP), NDF, Acid detergent fiber (ADF), NDF-protein (NDIP), ADF-protein (ADIP), lignin, crude oil and ash were determined on
selected samples. In the experiment, samples were inserted into the rumen of a cannulated cow for 6, 12, 24, 72, and 96 h
to determine in situ digestion. The average microbial purine to nitrogen ratio was determined to be 11.43. In situ
digested tall fescue microbial protein corrected CP values with purine and NDF methods were similar within all hours,
except 96 h. Other In situ digested sample purine procedure had some interference during sample reading and standard
errors were not acceptable level. There were not enough data to compare both methods for other samples.
