The nutritive value of Calluna Vulgaris: III. Digestibility at four and ten years after burning

Abstract

1. The necessity for further information on the digestibility of heather, with particular reference to the effect of age, has been discussed.2. The digestibility of well-defined samples of heather of 4 and 10 years of age has been determined.3. Four-year-old Blackface wethers in crates were fed diets containing 50% of heather and 50% of medium-quality meadow hay.4. The younger sample of heather was found to have appreciably higher digestibility coefficients for all nutritive constituents other than crude fibre.5. Agreement between duplicate sheep in respect of their capacity to digest crude protein was found to be good, and faecal metabolic nitrogen outputs were similar.6. Faecal metabolic nitrogen output was inversely related to the percentage of heather contained in the diet. No relationship between faecal metabolic nitrogen and bulk, as measured on a basis of volume per unit weight, could be established.7. It has been concluded that heather, though inferior as a source of protein, provides rather more energy than a poor-quality meadow hay, and is thus of value as a winter feed.