Effects of Packing Density and Inoculation with Lactic Acid-Producing Bacteria to Evaluate the Potential for North American Elderberry (Sambucus canadensis L.) Fodder as Silage

Abstract

Commercial elderberry production requires complete pruning in late fall to maintain productive canes. For integrated farms (livestock and crops), this biomass has potential as ensiled fodder for ruminant livestock. The objectives of this study were to determine the forage nutritive value of late-season (November) pruned elderberry (Sambucus canadensis L. “Rogersville”) fodder when ensiled. A 2 × 2 factorial laboratory silo experiment was conducted testing two packing densities with or without inoculation with lactic acid-producing bacteria silage inoculant to determine effects on silage nutritive values and fermentation parameters. Pre-ensiled elderberry fodder, composited from plants over 2000 m2, averaged 5.6% crude protein, 62.5% acid detergent fiber (ADF), 72.5% neutral detergent fiber, 11.4% non-fiber carbohydrates, 53% total digestive nutrients, and 52% relative feed value (RFV). The two packing densities were 160.2 kg dry matter/m3 and 240.3 kg dry matter/m3. Packing density did not affect any nutrient characteristics of the ensiled fodder. Acid detergent fiber was greater (p = 0.01) in un-inoculated silage, resulting in lower (p < 0.01) RFV for un-inoculated silage. Only lactic acid concentration was affected by packing density with greater concentrations (p = 0.04) in high-density silos. Inoculant affected several fermentation parameters with greater concentrations of (p < 0.01) propanediol, (p = 0.01) propanol, and (p < 0.01) acetic acid, while un-inoculated silages had greater concentrations of (p = 0.03) ammonia-nitrogen, (p < 0.01) lactic acid, (p = 0.02) succinic acid, and (p < 0.01) ethanol. Overall, late-season elderberry fodder was successfully ensiled, but nutritive value was low. Packing density did not affect nutritive value but did increase lactic acid concentration. Inoculation improved the RFV by reducing ADF, and though acetic acid production was greater in inoculated silage, total acid concentration was not affected.