“Grass Productivity: An Introduction to Rational Grazing”
by author André Voisin

Voisin developed four universal laws of “rational grazing” from his studies as a biochemist and from the many years of watching his cattle graze and putting his methodology into practice. He believed these laws “…must govern all rational grazing regardless of soil conditions, climate, altitude, latitude or longitude (page 193).” His four laws are based on requirements; the first two are focused on the grass and the last two, the cow.

[Please note, reference information for each law is presented as author’s name and page number; example (Voisin 194)]

First Law –   [Rest period Ave. 32 Days Crawford County – GRG]

Before a sward, sheared with the animal’s teeth, can achieve its maximum productivity, sufficient interval must have elapsed between two successive shearings to allow the grass:

1. to accumulate in its roots the reserves necessary for a vigorous spurt of regrowth;
2. To produce its “blaze of growth” (or high daily yield per acre) (Voisin 194)

Second Law –   [Don’t Graze the regrowth – GRG]

The total occupation period on one paddock should be sufficiently short for a grass sheared on the first day (or at the beginning) of occupation not to be cut again by the teeth of these animals before they leave the paddock (Voisin 196).

Third Law –   [Dairy (milk cows, calves, heifer), Beef (heifer, stockers, cows) – GRG]

The animals with the greatest nutritional requirements must be helped to harvest the greatest quantity of grass of the best possible quality (Voisin 198).

Fourth Law –   [Move your livestock every 12-24 hours – GRG]

If a cow is to give regular milk yields she must not stay any longer than three days on the same paddock. Yields will be at their maximum if the cow stays on one paddock for only one day (Voisin 199).

Voisin, André. Grass Productivity: An Introduction to Rational Grazing. Originally published 1959 as Productivité de l’Herbe. This edition ©2014 Midwest Journal Press. http://ruralsuburbanliving.worstell farms.com/p/books.html

GRG – Great River Graziers

These “Laws of Rational Grazing” are provided to you by: Great River Graziers of Crawford County & Crawford County UW-Extension, 608-326-0223