Silage maize systems improve dairy protein autonomy

This document evaluates nitrogen and protein autonomy in dairy farms using silage maize systems across Brittany and Pays de la Loire, part of the EU-funded TERUnic project under the SOS Protein plan. Seven specialized farms (avg. 118 ha, 93 ha forage) produced 705,000 L milk annually with 93 cows per farm. These systems achieved 63% protein autonomy—7% higher than conventional farms—due to optimized forage use and legume integration. Key metrics include 4,600 L autonomous milk per cow, MAT of 63%, and 19 ha land use per 100,000 L milk (6 ha external). Findings show silage maize systems reduce feed costs and external protein reliance, but remain dependent on soybeans for ration balance. Strategies like legume rotation and nitrogen correction improve sustainability. Organic and grass-based systems outperform in autonomous milk yield (5,300–6,500 L/cow). The project emphasizes balancing silage maize with legume-rich forages to enhance protein autonomy and reduce external inputs.