Press Releases

Dutch breeders of forage crops claim that a considerable increase of farmers income is possible by focussing on digestibility. Five percent higher digestibility of Perennial ryegrass leads in Dutch circumstances to 100 guilders more income per cow per year. In other farming systems and other forage crops the effect should be comparable.

Five percent higher digestible Perennial ryegrass provides 100 Dutch guilders more income per cow per year. That's proven by a simulation-model of the Dutch Dairy Research Station (PR). The improved income is due to a decreased need of concentrates. In other farming systems higher digestibility has similar effects on the income. Higher digestibility leads to higher energy-intake, through which farmers can increase the output without spending money. The relatively low cast of grassland renovation are the only investment the farmers have to do.

Grazing-trial with dairy cows

Dutch research workers are going to check the exactness of the computer calculations by performing a grazing trial with dairy cows. The grass grazing-trial is an acknowledgement for the research the Dutch grass seed company Barenbrug has done on digestibility breeding for several years. Grazing trials with dairy cows are expensive and do not often occur.

Next spring, Perennial ryegrass populations of maximum variation in digestibility will be sown at a research farm in the Netherlands. The first milk production results of dairy cows grazing on this trial field can be expected in 1999.

Genetic variation

The present Dutch ryegrass varieties differ about two percent in digestibility. 'If breeders will focus more on improving this characteristic, differences of five percent are possible', expects Robert van Loo, research worker at the Center for Plant breeding and Reproduction Research (CPRO). Some other species, like cocksfoot, show even more genetic variation. Barenbrug found similar genetic variations between varieties, tells Director of Research Laurens Beerepoot. He underlines the conclusions of Van Loo.

Nitrogen-utilisation

By breeding on digestibility Dutch researchers tend to pay at least as much attention to cellwall digestibility as to the ratio cell-content/cellwall. Since the variation in cellwall digestibility appears to be more genetically defined than cell-wall content. Dairy feed researcher Albert van Vuuren (Dutch cattle Research Center ID-DLO) adds some more arguments: 'A lack of structure (cellwalls) causes high production of volatile fatty acids in the rumen. Digestion problems will be the result'.

Higher cellwall-digestibility also increases the nitrogen-utilisation, supposes Van Vuuren. 'The digestion products of the cellwall improve the balance between protein and energy in the rumen of a grazing cow. More feed-protein will be converted into milk protein. That reduces the nitrogen-loss in manure and urine'.

Barenbrug Holland BV
Info: jreinhoudt@barenbrug.nl
Fax: +31 (481) 488190

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