The use of faecal near infra-red spectroscopy to predict dietary digestibility and crude protein content of cattle fed supplements

Abstract

Faecal near infra-red spectroscopy (FNIRS) is a recent technology that has been demonstrated to predict dietary crude protein (CP) content and dry matter digestibility (DMD) of ruminant feeds from faecal samples (Stuth et al. 1999). Microbial protein production (MCP) is an important parameter in evaluating ruminant nutrition, but conventional methods of obtaining predictions are difficult, costly, and subject to potentially large laboratory errors. It was hypothesised that, as MCP is dependent on the physical structure and chemical composition of the feed (which includes, but is not limited to, DMD and CP content), and FNIRS has been demonstrated to deliver specific information on the structure and content of the diet, then a FNIRS model could be constructed to predict MCP from faecal samples. Such a model would be valuable in contemporary production decision support systems. This work sought to develop a preliminary pilot model to assess this.