Tannins and antinutritional factors
Sweet potato peelings contain phenolic compounds ranging from 1-6 gallic acid equivalent /g DM (Akoetey et al., 2017). The presence of protease inhibitors has been mentioned as a cause for the lower than expected nutritional values of sweet potato wastes (Zhang et al., 2019).
Toxicity
Tubers that are mouldy, rotten, or injured can be contaminated with fungi that produce toxic metabolites (ipomeamarone, 4-ipomeanol) that may cause serious health problems, particularly respiratory ones, in livestock. It is thus recommended to not distribute mouldy sweet potato by-products to farm animals (Wilson, 1973; Poore et al., 2000).
Acidosis and laminitis
Sweet potato by-products rich in fermentescible carbohydrates must be introduced into the diet progressively and well supplemented in forage and protein in order to avoid acidosis and laminitis (MSU, 2010).
Teeth damage
Sweet potato cannery wastes have a low pH and a high lactic acid content that can severely damage cattle teeth, by eroding enamel, releasing calcium, and blackening incisors. This can be solved by increasing the pH above pH 4 before feeding the animals (Poore et al., 2000; MSU, 2010)