Abstract

This review quantitatively compares the nutritive value of ryegrass and clover. It confirms that the animal performance on clover is on average 40% higher than on ryegrass. It establishes that although the digestibility of clover is less affected by stage of vegetative growth than ryegrass, the digestibility and metabolisable content of the two species is little different when compared at a young vegetative stage. Although the crude protein content of clover is often higher than that of grass the ratio of metabolisable protein to metabolisable energy supply is similar from the two forages. Despite a similar metabolisable energy content, the utilisation of metabolosable energy for growth is higher for clover than ryegrass. This may be due to a greater proportion of energy digestion in the small intestine. Most of the elements of ingestive behaviour, bite size, biting rate and intake rate are greater for clover than ryegrass and consequently the total gazing time and thus cost of harvesting clover are lower. The review concludes by estimating the relative contribution of increased efficiency of utilisation, reduced costs of ingestion and increased intake to the higher animal performance from clover.

AM, Nicol, and GR Edwards

Proceedings of the New Zealand Society of Animal Production, Volume 71, Invercargill, 71-78, 2011