Chemical composition and gas production kinetic parameters of sweet potato vine waste silage after preserved for short and prolonged periods

Abstract

The sweet potato (Ipomoea batata L.) culture produces by-products with animal feeding potential, such as vines. Given that sweet potato vines are seasonal and highly perishable, the adoption of conservation strategies such as silage becomes necessary to ensure their availability during food shortage periods. The knowledge of the optimal conservation period of this type of silage is limited, with very few studies available on this topic. The objective of this work was to evaluate the chemical composition, fermentative characteristics, and in vitro gas production kinetics of sweet potato vine silage after 45 and 120 days of conservation and to compare them with those of fresh sweet potato vine. The sweet potato vines were collected, cut into 2-3 cm pieces, and ensiled for 45 and 120 days. After this period, the nutritional value was determined using the standard methods of AOAC. The gas production and kinetics were fitted to the exponential equation proposed by Ørskov and McDonald. It was found that the sweet potato vine can be successfully preserved as silage, regardless of the conservation period, and that it shows a high potential for being used as an alternative food source for ruminants. In vitro dry matter and organic matter digestibility were not much different for the fresh sweet potato vine, and the silage was conserved for 120 days. However, the silage for 120 days had lower accumulated in vitro gas production compared to the fresh sweet potato vine. It was concluded that the silage conservation period did not produce significant changes in chemical composition or in vitro digestibility, with the sweet potato vine showing good nutritional values both fresh and after a conservation period. Therefore, sweet potato vine silage can be used as an alternative food source in ruminant diets.