ASSESSMENT OF DIETARY ENZYME SUPPLEMENTATION ON ILEAL AND TOTAL TRACT DIGESTIBILITIES IN GESTATING AND LACTATING SWINE

The objective of this dissertation was to evaluate the effects of exogenous enzyme supplementation to gestation-lactation diets on the digestibility of nutrients in mature swine females and the associated implications on energy metabolism during gestation and lactation physiologic states. Three experiments were performed to evaluate the effects of commercially available enzyme products or pure enzymes on the digestibility of nutrients. Crossover designs in two periods during gestation (early and late gestation) and lactation were studied to obtain an increased number of observations from the surgically cannulated sows. Experiment 1 evaluated the effects of two enzyme products supplemented to a practical corn soybean meal diet fed to second parity crossbred sows. One of the enzyme products contained both protease and cellulase activities, and the other xylanase activity, both products were produced by microbial fermentation. No effects (P> 0.10) were observed during either periods during gestation. During lactation, effects of both enzyme products were observed for digestibility of nutrients. Protease/cellulase supplementation increased ileal digestibility of gross energy (P < 0.09). Xylanase supplementation produced higher ileal digestibilities of dry matter, nitrogen and gross energy (P < 0.02), improvements that were maintained for the total trac