Digestibility of Energy and Caloric Value in Nursery Pigs Fed Commercially Available Lipids

ABSTRACT Objective The objective was to determine the DE of various lipids and compare these values with predicted values based on published equations. Materials and Methods Pigs (480) weaned at 24 d of age were fed a common diet for 7 d after which they were fed a basal or lipid-based diet for 28 d. Lipids (7.13%) were added in place of the basal diet, and all diets were pelleted and offered ad libitum. Fecal samples were collected on d 25 from 2 pigs per pen and pooled for subsequent analysis. Apparent total-tract digestibility of GE of the diet was determined by the indirect method and the DE content of each lipid source using the difference procedure. Results and Discussion The DE for butter fat, canola oil, coconut oil, fish oil, flaxseed oil, lard, olive oil, palm oil, soybean oil, and tallow was 8,911, 9,474, 9,380, 9,464, 8,584, 8,648, 9,606, 8,304, 9,979, and 8,071 kcal/kg, respectively. Using these values and the chemical composition of each lipid, the best fit prediction equation was DE, kcal/kg = 10,267 − (110.3 × FFA, %) − (41.8 × C16:0, %) − (39.7 × C18:0, %) − (98.0 × unsaturated:saturated ratio) + (6.4 × iodine value), SE = 164, R2 = 0.97, P = 0.01. Implications and Applications The determined DE herein were approximately 12% greater than predicted based on published equations, indicating the refining of published prediction equations is needed. These results indicate that DE of lipids can vary depending on their fatty acid composition, which consequently affects pig performance.