Ensiling of Potato Vines

Potato vines are a potential feed for cattle if the vines can be preserved. The objectives of this study were primarily to study alternative methods to preserve potato vines by ensiling and determine the effects of soil contamination on ensiling. In experiment 1, vines from four potato varieties were harvested individually with a flail chopper set at three heights to vary soil contamination. The chopped vines were ensiled in minisilos alone or amended (3:1, vines to amendment, wet basis) with either chopped alfalfa hay or barley grain. Silos were opened after 90 d for analysis. In experiment 2, vines of one variety were hand-harvested and ensiled fresh or after wilting one day in a greenhouse, alone or in combination with chopped whole plant corn at one of four levels. Silos were opened for analysis after 1, 2, 6, 14 and 90 d ensiling. The vines in both experiments were of high nutritive value with high crude protein contents [194-261 g kg–1 dry matter (DM)] and low neutral detergent fiber contents (286-359 g kg–1 DM). However, ash contents were relatively high even with low soil contamination (220-307 g kg–1 DM) and hand-harvested vines (169 g kg–1 DM). In both experiments, unamended vines were poorly preserved, underwent a secondary fermentation, and were unstable aerobically. Little or no lactic acid was present in these silages, acetic acid was the predominant fermentation product, and butyric acid was detected in some silages. In contrast, all three amendments produced well-preserved silages. Barleyamended silages yielded the lowest pHs (4.06 average); alfalfa-amended silages yielded the highest (4.97 average). In a 5-d aerobic stability test, some barley-amended replicates heated while none of the alfalfaor corn-amended silages heated. Level of soil contamination had no consistent negative effect on fermentation, but the added soil substantially diluted vine dry matter in the high contamination treatments.