Effects of a novel onboard sorghum kernel processor and height of cut on berry processing score and ruminal in situ starch disappearance of forage sorghum ensiled for 0 and 90 days

Abstract

The objectives of this experiment were to evaluate the effects of forage sorghum silage harvest settings, combining cut height, onboard sorghum kernel processor (KP) technology, and ensiling duration, on berry processing score (BPS_2.36) and ruminal in situ starch disappearance at 7 h (isSD7). Three harvest settings were tested: a 20-cm cut height, with and without KP (Low+KP, Low-noKP), and a 120-cm cut height with KP (High+KP). A commercial sorghum field was divided into 9 squares, with 3 squares randomly selected as blocks. Duplicate samples were collected and ensiled in vacuum-sealed bags for 0 or 90 d. Samples were analyzed for nutrient composition, BPS_2.36, and isSD7. Raising the cut height from 20 to 120 cm increased DM, CP, and starch content, and reduced ADF and NDF. The BPS_2.36 was lowest for Low-noKP, intermediate for Low+KP, and highest for High+KP (8.16%, 56.2%, and 70.8% ± 1.04% of starch, respectively). The isSD7 was increased for kernel-processed sorghum ensiled for 90 d compared with unprocessed or nonensiled samples. The sorghum KP set at 0.5-mm roll clearance enhanced BPS_2.36 of sorghum, which considerably improved isSD7 following 90 d of ensiling storage duration.