Full fat rapeseed is not usually used in livestock feeds because the extracted oil is too valuable. However in some circumstances it may be worthwhile using full fat rapeseed as a protein and energy supplement. Intact seeds are only poorly digested so it is necessary to physically disrupt the seed to allow efficient digestion. Milling the seeds may allow myrosinase catalysed hydrolysis of glucosinolates yielding products which adversely affect palatability and nutritive value. Dry extrusion offers a means of simultaneously crushing the seed and denaturing the myrosinase by high temperature (130°C). Previous short term studies with rats and pigs have indicated that extrusion may improve the nutritive value of diets containing 12.5% high glucosinolate rapeseed (HG-RS).

The present work involved a production trial to study the longer term effects of diets containing 12.5% rapeseed and a metabolism study to investigate the digestion and short term effects of pig diets containing 25% rapeseed.