259 - Impact of Reducing Dietary Protein with Supplementation of 8 Essential Amino Acids and Functional Roles of Supplemental His or Glu on Growth Performance and Carcass Traits of Finishing Pigs

Tuesday, June 28, 2022

4:15 PM – 4:30 PM CT

Location: Oklahoma City Convention Center, Ballroom A

Presenting Author(s)

Marcos Elias E. Duarte, PhD

Associate Research Scholar
North Carolina State University
Raleigh, NC

Author(s)

Zixiao Deng

PhD Student
North Carolina State University
Raleigh, NC
JB

Jonathan Baker

North Carolina State University
Raleigh, NC
Sung Woo Kim, n/a

Professor
North Carolina State University
Raleigh, NC

Abstract: This study evaluated the effects of reducing dietary protein with supplementation of 8 essential amino acids and functional roles of supplemental Glu or His on growth performance and carcass traits of finishing pigs. Pigs (n = 216; 98 ± 3.5 kg BW) were allotted (3 pigs/pen) to 4 treatments in a randomized complete block design (RCBD) with sex and initial BW as blocks. Pigs were fed for 14 d until 120 kg BW. Dietary treatments were CON (11.4% CP with L-Lys, L-Thr, and L-Trp); LCP (8.9% CP with L-Lys, Thr, Trp, Met, Val, Ile, Phe, and His); LCPG (9.1% CP; LCP+Glu to match % Glu in CON); and LCPH (9.2% CP; LCP+2x His requirement). Diets met or exceeded requirements with 2.7 Mcal/kg NE. Growth performance and backfat thickness (BFT) were measured at d 0 and d 14. Blood was collected to analyze BUN. At d 14, pigs with the median BW in each pen were slaughtered. Pigs fed CON had greatest (P < 0.05) BW, ADG, and G:F. Pigs fed LCP had greater (P < 0.05) BW, ADG, and ADFI than LCPG. BFT of pigs fed LCPG and LCPH was less (P < 0.05) than CON. Cold carcass weight in CON was greater (P < 0.05) than LCPG and LCPH, whereas it was greater (P < 0.05) in LCP than in LCPG. Chilling loss in LCP was less (P < 0.05) than LCPG. Drip loss at 48 h in LCPH was less (P < 0.05) than CON and LCPG. BUN in LCPG and LCPH was less (P < 0.05) than CON. In conclusion, reducing dietary protein by 2.5% using 8 supplemental amino acids reduced growth performance without affecting carcass yield. Supplemental His at 2x requirement to low protein diets meeting His requirement enhanced loin quality by reducing drip loss.