Nutritive value of whole crop wheat silage harvested at three stages of maturity

Abstract

The effect of stage of maturity on the ensiling properties of two wheat cultivars was studied under laboratory conditions. Turkish wheat cultivars, Pehlivan (P) and Gotten (G) were used in this experiment. Whole crop wheat was harvested at three maturation stages: flowering, milk, and dough. The chopped forages were ensiled in 1.5-1 anaerobic jars. Three jars per treatment were sampled on days 2, 4, 8, 15 and 90. After ensiling for 90 days, the silages were tested for aerobic stability in a test in which CO2 production was measured along with chemical and microbiological parameters. In addition, fibre analysis was performed the three stages of maturity of the wheat and rumen degradability of the silages was measured by the in situ procedure. All silages were well preserved. The pH and water-soluble carbohydrate (WSC) decreased in the silages with maturity. The silages from the milk and dough ripening stages contained more lactic acid but less ethanol, yeasts, moulds, and clostridia than at flowering in both varieties. All silages were stable under aerobic conditions. In both varieties, fibre contents decreased (P < 0.05) in the dough ripening stage as compared with the flowering and milk stages. The neutral detergent fibre (NDF) content of silages decreased from 540 to 412 g kg(-1) dry matter (DM) in P and from 534 to 442 g kg(-1) DM in G (P < 0.05). The hemicellulose content did not change consistently throughout the growth period of the wheat, but the crude protein (CP) content decreased in the dough ripening stage as compared with the flowering and milk stages. The crude protein content decreased from 78 to 61 g kg(-1) DM in P and from 75 to 58 g kg(-1) DM in G (P < 0.05). In the two wheat cultivars, the highest in situ dry matter degradability and degradable yields were obtained at dough ripening stage. The highest fibre degradability was obtained at flowering, but yields of degradable neutral detergent fibre occurred at dough ripening stage. Therefore, wheat cultivars P and G, should be harvested at dough ripening stage is the most recommended.