BACKGROUND: An understanding of the dynamics that affect the nutrient content of forages with advancing growth stages is critical for designing equally dynamic feeding programmes. This study compared the agronomic characteristic and feeding values of forages from barley, rye, wheat, oats and triticale weekly from tillering (Z 24-25) to dough stages of maturity (Z 83-87). RESULT: Digestible dry matter yield of cereal species increased rapidly (P < 0.05) from 1.9 t ha(-1) at tillering to 7.8 t ha(-1) at ear emergence (Z 50-55) and remained stable (P > 0.05) until the dough stage when it increased to 10.4 t ha(-1) . The nutritive quality of cereal species decreased with advancing growth stages, and this was more pronounced in barley and rye with rapid reductions in their energy and digestibility values. Changes in the nutritive value of cereal forages indicated a strong relationship (P < 0.05) with the leaf-stem ratio of the plants. The animal response reflected the changes in feeding value of cereal species with advancing growth stages. The average live weight gain of lambs decreased (P < 0.05) from an average of 203 g d(-1) on 2 May to 142 g d(-1) on the 13 June. CONCLUSION: Wheat and oats, and to a lesser extent triticale, provided higher quality forages than barley and rye. All cereal species had poor feeding qualities between ear emergence and milk stages (Z 71-75). © 2016 Society of Chemical Industry.