Rusitec has become the method of choice when studying the in vitro ruminal effects of the gram-positive ionophore monensin. The objective of the current study was to determine the in vitro effects of monensin treatment on volatile fatty acid (VFA) molar production and methane production from two complete diets which varied in maize silage:grass silage ratio and NaOH treated wheat grain:molassed sugar beet feed (MSBF) ratio.

Synchronisation between the rates of energy and nitrogen supply to the rumen microbes is considered important in terms of maximising the amount and efficiency of rumen microbial protein synthesis (Chamberlain and Choung, 1995). As part of a research programme examining the effects of diets which have been formulated to be asynchronous or synchronous with respect to the potential hourly supply of energy and nitrogen to the microbial fraction on gastro-intestinal tract metabolism, this study reports on the effects of these diets on rumen function, assessed in vitro, using Rumen Simulated Continuous Culture (RSCC).

Public attitudes and expense encourage the replacement of in vivo forage evaluation techniques with non-invasive, laboratory-based techniques. This study assessed the accuracy of predicting the metabolisable energy (ME) content of whole crop wheat (WCW) from less animal-dependent techniques.

NIRS has proved to be a rapid, accurate method of evaluating grass silage quality parameters using dried, milled samples. Recent research by Park et al., (1996) has shown that undried silage can be used to accurately estimate a wide range of chemical and biological parameters. The digestibility and degradability fractions of silage are important indicators of silage nutritive value. This study was undertaken to further explore the potential of NIRS as a means of predicting a range of digestibility and degradability components of undried grass silage.

Traditional methods for the determination of the different nitrogen fractions present in milk are very time consuming, involving two separate Kjeldahl analyses. The NIR technique requires little sample preparation and allows simultaneous determination of parameters once a suitable population has been compiled to make a reliable and robust calibration. This study investigated the use of NIR to determine crude protein, whey protein and casein protein fractions in fresh milk.

The size of biological samples is often, by necessity, small and precludes a full and detailed chemical analysis of the material. Near infrared spectra are comprehensive records of the chemical structure and content of a substrate and are thus a rich source of information. To investigate diurnal changes in the chemical composition of duodenal digesta, NIR spectra and difference spectra were used to examine samples collected over a 24h period.

Most protein systems include an estimation of the proportion of protein (nitrogen x 6.25) which is immediately soluble in the rumen. However, since the procedures employed generally involve mechanically washing samples in cold water the validity of these values have been questioned. The aim of the present experiment was to compare different solvents with rumen liquor for determining the proportion of soluble dry matter (DM) in grass and grass silage.