Simplification du pâturage pour les troupeaux allaitants et les bovins d'élevage

Simplification of the grazing system for suckling herds and growing cattle

To the special constraints of the rearing of suckling stock (low profits and Iimited mvestments, limited labour, management of several herds. necessary autonomy of the forage system ... ) may sometimes be added sorne climatic constramts (altitude, continental clirnate with Summer irregularities), the consequences of which may he important.The overall results of five trials (two in the mountains, two in continent allowlands, one in « oceanic» lowlands), where the simplification of grazing was studied for suckling cows, heifers, and growing cattle from dairy breeds, show that intensive set stocking gives 5 to 15 % smaller animal returns than paddock grazing, and that the balance between the forage resour¬ces over the seasons is modified by set stocking.In Spring, the animacs' performances are similar, but sometimes to the detriment of the available Summer grass : with the set stocking system, the plots are grazed earlier after a cut so that silage making is preferable.In Summer, the average performances drop under set stocking: by 2 to 11 % for growing calves, by 6 to 29 % for the weight gain of cows, by 9 to 27 % for growing cattle. In extreme cases, feed complementation on the pasture or an early return indoors become necessary, reducing thus the available Winter resources.The applied stocking rates (1,4 to 2 couples mother-cow + calf per ha in Summer and Autumn and 1 500 to 2 500 kg live weight per ha) are much too high and where certainly detrimental to the set stocking system. Stocking rates of 1,1 to 1.5 couple per ha would have been more suitable. Lastly, the consequences of set stocking are more or less important according to the kind of grazing animals.