170 Nutrient digestibility of degermed, dehulled corn, citrus pulp, and soy protein concentrate by barrows U. S. Ruiz,*† 1 M. C. Tomaz,* L. A. F. Pascoal,*‡ P. H. Watanabe,*§ A. B. Amorim,*# G. M. P. Melo,* and E. Daniel* *Univ. Estadual Paulista, Jaboticabal, 14884 – 900, Brazil; †Univ. Estadual Paulista, Dracena, 17900 – 000, Brazil; ‡Univ. Federal da Paraíba, Bananeiras, 58220 – 000, Brazil; §Univ. Federal do Ceará, Fortaleza, 60020 – 181, Brazil; and #Univ. Estadual Paulista, Botucatu, 18618 – 970, Brazil 1 Corresponding author: usruiz@dracena.unesp.br ABSTRACT: This study was carried out to determine apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of DM, CP, GE, and their respective digestible content of degermed dehulled corn (Zea mays), citrus pulp, and soy (Glycine max) protein concentrate by pigs using the difference method. Thirty- two barrows (28.1 ± 1.6 kg of BW) were fed a corn– soybean meal basal diet or 1 of 3 diets formulated by replacing 30% of the basal diet with 30% of 1 of the test feedstuffs for 11 d. Chromic oxide (0.3%) was included in the diets. Feces were collected from days 7 to 11 by grab sampling and ileal digesta were collected after pigs were slaughtered on day 12. The AID of DM and AID and ATTD of GE of degermed corn (77.4, 88.7, and 77.7%) were greater (P < 0.05) than those observed in citrus pulp (50.3, 86.5, and 55.8%) and in soy protein concentrate (63.5, 85.1, and 59.4%), which did not differ (P > 0.05). The ATTD of CP, total digestible CP, and total DE of soy protein concentrate (87.5%, 500 g/ kg, and 3739 kcal/kg) were higher (P < 0.05) than the values in degermed corn (81.7%, 57.5 g/kg, and 3330 kcal/kg), which were greater (P < 0.05) than those in citrus pulp (60.5%, 39.5 g/kg, and 3223 kcal/kg). Total and ileal digestible DM, AID of CP, and ileal DE of degermed corn (782 g/kg, 673 g/kg, 70.7%, and 2913 kcal/kg) and soy protein concentrate (778 g/kg, 570 g/ kg, 78.7%, and 2878 kcal/kg) were similar (P > 0.05) and greater (P < 0.05) than those in citrus pulp (737 g/ kg, 436 g/kg, 50.6%, and 2081 kcal/kg). Ileal digestible CP of degermed corn (49.8 g/kg) and citrus pulp (33.0 g/kg) did not differ (P > 0.05) but were smaller (P < 0.05) than the value found in soy protein concentrate (434 g/kg). The DM and energy from degermed corn are more efficiently digested by the pig than those from soy protein concentrate and citrus pulp. Soy protein concentrate was the best protein source evaluated in this study. Keywords: digestion, feedstuff, pig © 2012 American Society of Animal Science. All rights reserved. J. Anim. Sci. 2012.90:170–172 doi:10.2527/jas53863 INTRODUCTION The amount of nutrients that pigs can digest and absorb from feedstuffs is important information to formulate diets accurately, avoiding excess or lack of nutrients for pigs. Many factors influence nutrient digestibility of feedstuffs, such as feed composition, especially dietary fiber content (Le Goff et al., 2002). The objectives of this study were to determine and compare in barrows the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of DM, CP, and GE of 3 feedstuffs with a range in dietary fiber content: degermed, dehulled corn, which is low in fiber, citrus pulp, which is high in soluble fiber, and soy protein concentrate, which is high in insoluble fiber. MATERIALS AND METHODS The animal procedures were reviewed and approved by the Universidade Estadual Paulista Committee of Ethics and Animal Welfare and followed guidelines established by the Brazilian Council of Animal Experimentation. This trial was conducted at the Swine Production Sector of the Animal Science Department at Universidade Estadual Paulista, Campus of Jaboticabal – SP, Brazil. Thirty-two barrows (28.1 ± 1.57 kg) of a commercial line (Topigs do Brasil, Campinas, Brazil) were used and fed 1 of 4 diets: a basal diet based on corn Published January 23, 2015