Effect of harvest date on botanical, morphological, and nutritional composition of mixed crops of small-grain cereals for silage

Resumen

Objective: To evaluate the effect of harvest date on the botanical, morphological and nutritional composition of silage from small grain cereal mixtures.

Design/methodology/approach: Laboratory silages of three crops of small grain cereal mixtures (BR, barley + rye; BT, barley + triticale and RT, rye + triticale) were made on two harvest dates (HD1, 60 days and HD2, 80 days post-sowing). Statistical analysis was performed under a 3x2 factorial model, and the variables were botanical, morphological and nutritional composition.

Results: The proportion of cereal decreased from HD1 to HD2 (p<0.05). Spikes and stems in barley and triticale increased in HD2. Rye had a high proportion of stems on both dates. Crude protein (CP) decreased and neutral detergent and acid detergent fiber increased in HD2 (p<0.05). The variables pH, dry matter content, digestibility and metabolizable energy were affected by the interaction between harvest date and mixture (p<0.05). RT quality had less variation between HD1 and HD2 and BT had more CP, less fiber and presented higher digestibility and energy content (p<0.05).

Limitations on study/implications: Knowing the characteristics of a cereal mixture depending on the harvest date can help in making decisions to produce quality silage.

Findings/conclusions: Harvest date influences the proportion of components in small grain cereal mixtures for silage, on their morphological and nutritional composition; effect that depend to the cereal species in the mix.