Laying alfalfa in wide vs. narrow swaths improved its drying rate but had little effect on silage quality in a University of Delaware study.
Three cuttings from the same field were cut with a mower-conditioner to leave narrow (4-5') or wide (8-9') swaths. Samples were collected, then dry matter was monitored until a target of 43-45% dry matter was reached. The forage was chopped and ensiled in bags for about 65 days.
Wide swathing had a big impact on field drying time. The hours of wilting time for narrow and wide swaths at the first, second and third cuttings were 50 vs. 29, 54 vs. 28 and 25 vs. 6, respectively. On average, wide-swathed alfalfa was chopped 22 hours earlier than narrow-swathed alfalfa.
At the time of ensiling, wide-swathed alfalfa had more water-soluble carbohydrates. That silage ended up with a lower pH, but lactic and acetic acid contents were identical in the two silages. Ash, NDF and NDF digestibility also were the same, although wide-swath silage had a slightly lower N content.
The researchers concluded that the quality of wide- and narrow-swath silage was generally the same.