Effect of feed technologies on the digestibility of energy and nutrients in diets fed to growing pigs

Abstract

A total of 6 experiments were conducted and structured in 4 chapters to evaluate the effects of feed technologies on the digestibility of energy and nutrients in diets fed to growing pigs. For Chapter 1, four dietary treatments were used in 2 experiments, consisting of a mash diet and 3 pelleted diets that were conditioned at 30, 60, and 180 seconds to determine the effects of conditioning time on AID of CP and AA and concentration of DE and ME. The results indicated that increasing conditioning time up to 180 seconds improved the SID of CP and most AA, and pelleting increased the ATTD of GE, but there was no evidence of difference in DE and ME concentrations. For Chapter 2, a total of 12 cannulated pigs were used, and 4 dietary treatments were manufactured, consisting of a mash diet and 3 pelleted diets using 3 different pellet dies of length-to-diameter ratio (L:D) of 6, 8, and 10. Results from this experiment indicated that pelleting diets leads to improvements in SID of CP and AA; however, this improvement is dependent on pellet die thickness, with thicker dies, such as L:D 8 or 10, improving SID of AA. For Chapter 3, a group of 10 pigs was used to test the effect of myristic acid, protected benzoic acid, and aspergillus niger cultures on the ATTD of GE and nitrogen retention in high fiber diets fed to growing pigs. Results indicate a tendency (P < 0.15) of myristic acid and protected benzoic acid diets to have increased concentration of ME compared with the negative control diet, with the aspergillus culture diet being intermediate. However, no effect was observed due to the inclusion of feed additives on ATTD of GE or nitrogen retention. For Chapter 4, 2 groups of growing pigs were used, and 2 experiments were designed to determine the effect of protease inclusion on the ATTD of GE and nutrients and SID of CP and AA. These results indicate that the inclusion of protease at 4,000 U/kg increases the digestibility of nutrients when included in diets fed to growing pigs. These data can be used during feed formulation to ensure that adequate concentrations of digestible nutrients are being provided to the animals to support their growth.