The objective of this experiment was to evaluate the fermentative quality of sorghum silage of small, medium and high size with different stem+leafs/head proportions (100:00, 80:20, 60:40, 40:60, 20:80, 00:100), by means of lab analysis. The whole plant was used as control. The hybrids were cultivated and ensiled at 104 days of age in PVC lab silos measuring 10-cm of diameter by 40-cm of length (three replications per treatment). Silos were opened 56 days after the ensilage. The crude protein (CP) contents and the in vitro dry matter disappearance (IVDMD), total phenols, constituents of cell wall by sequential method. The differences were compared using SNK test for total phenols, being realized regression analysis for the other results. Original material soluble carbohydrates values were low for the majority of the treatments, but this did not prejudice the fermentation, because additional carbohydrates like hemicellulose and cellulose were used during ensilage, being the fall of these high in the heads and stem+leaves, respectively. Total phenol values increased with the ensilage, besides decrease in IVDMD did not occur, concomitantly. The heads addition to the plant reduced cell wall constituents and increased IVDMD values, indicating that, to produce good quality silage, a sorghum plant shall has, at least, 40% of heads and low lignin, tannins and cell wall constituents values.
quality; stem+leafs/head proportion; silage; sorghum