Les fourrages et la production de protéines

Forages and protein production

Forage crops and pastures supply approximately 85% of the protein requirements of ruminants, and this proportion can be increased still further by developing the legume forage crops (lucerne and grass/legume associations), by breeding, and by improving the harvesting techniques. On the other hand, there is a problem caused by the great solubility of the leaf proteins, which is linked to their essential metabolic function, and which varies among species. Dehydration is a means of diminishing strongly this solubility. A greater protein self-sufficiency has to be obtained while maintaining low nitrate leachings. The dairy systems that strive for protein self-sufficiency are relatively well-performing and, when coupled with cereal systems, lead to a noteworthy improvement of the nitrogen balances of the farms. At the field level, losses through leaching increase with the stocking rate, but are smaller under a grass/clover association than under a pure ryegrass crop. Attention should be given to possible losses when ploughing-up perennial forage crops. More globally, forage legumes and grass/legume associations are ideal means of combining protein self-sufficiency and a low consumption of fossil energy; moreover, pastures do immobilize carbon in a strong way.