Study of variability in French cereals

Abstract

Annual surveys have been carried out to determine the physical characteristics, the chemical composition and the poultry metabolizable energy of French cereals. Means and the variability (on dry matter (DM) basis), correlations between criteria and relationships between energy and criteria have been established. For wheat, on average, starch, crude protein contents and metabolizable energy are 68.9 ± 0.8%, 13.2 ± 0.9% and 14.5 ± 0.2 MJ kg −, respectively. Starch and crude protein contents show bctween-year and between-region variability. Barley composition differs between two-rowed and sixrowed varieties: crude protein content is 12.2 ± 0.9% and 11.4 ± 0.9%, crude fibre is 4.7 ± 0.4% and 5.2 ± 0.5% and metabolizable energy is 13.5 ± 0.2 MJ kg −1 and 13.1 ± 0.3 MJ kg −1, respectively. Maize composition is fairly constant: on average, starch, crude protein contents and metabolizable energy are 73.6 ± 0.7%, 9.9 ± 0.4% and 15.7 ± 0.1 MJ kg −1, respectively. Black oats have less starch, less ether extract, less metabolizable energy, more crude protein and more crude fibre than white oats (39.8 ± 0.4% vs. 43.6 ± 0.8%, 5.6 ± 0.4% vs. 6.8 ± 0.4%, 11.1 ± 0.3 MJ kg −1 vs. 11.2 ± 0.2 MJ kg −1, 1.4 ± 0.9% vs. 11.0 ± 0.3% and 13.3 ± 0.3% vs. 12.2 ± 0.4%, respectively). Rye starch and crude fibre contents are 63.2 ± 1.1% and 2.2 ± 0.1%, respectively. Crude protein content (10.0 ± 1.4% on average) is higher in the plains than in the mountains, and varies from one year to another. Metabolizable energy (13.1 ± 0.5 MJ kg −1 on average) varies from one year to another. Triticale starch, crude protein, crude fibre contents and metabolizable energy are nearer the wheat values than these for rye (66.3 ± 1.4%, 12.2 ± 1.2%, 2.8 ± 0.3% and 14.3 ± 0.2 MJ kg −1, respectively). Sorghum crops are tannin-free varieties. Their starch, crude protein contents and metabolizable energy are 73.0 ± 1.1%, 12.5 ± 0.7% and 16.1 ± 0.1 MJ kg −1, respectively.