TY - JOUR
T1 - Immune system stimulation increases dietary threonine requirements for protein deposition in growing pigs
AU - Mcgilvray, Whitney D.
AU - Wooten, Hailey
AU - Rakhshandeh, Amanda R.
AU - Petry, Amy
AU - Rakhshandeh, Anoosh
N1 - Funding Information:
The current study was presented in part in the proceedings of the American Society of Animal Science meeting (Midwest section 2017), Omaha, NE, USA. The authors express their deep gratitude to Professor Cornelius F.M. de Lange for his intellectual contributions to this study. The present study was funded by Texas Tech University (internal funds). This research is a publication from the Department of Animal and Food Sciences, Texas Tech University. This study was conducted at the Texas Tech University Swine Research facility.
Publisher Copyright:
© The Author(s) 2018.
PY - 2019/2/1
Y1 - 2019/2/1
N2 - Previous studies have reported an increase in the utilization of threonine (Thr) during immune system stimulation (ISS). However, increased utilization of an AA during ISS may not reflect an increased dietary requirement, as endogenous sources may supply AA to meet the need for enhanced utilization. The current study evaluated the impact of ISS on components of dietary Thr requirements, i.e., maintenance requirement and the efficiency of Thr utilization. Thirty-nine gilts (initial BW 32 ± 2.1 kg) of commercially relevant genetics were individually housed in metabolism crates and fed one of six experimental diets in which Thr was the first limiting among other AA. Three levels of dietary Thr were tested within each ISS group: 70%, 90%, and 110% of daily Thr requirements, which were estimated based on the potential of each ISS group for protein deposition (PD). Following adaptation to the experimental diets, pigs from each dietary treatment group were injected with either increasing amounts of Escherichia coli lipopolysaccharide (ISS+; 25 and 35 μg/kg BW) or saline (ISSâ '). Injections were given 48-h apart and whole-body nitrogen balance was measured for 72-h following the first injection. Body temperature (BT) was monitored and blood samples were collected 24 h after initiation of ISS and evaluated for measures of blood chemistry. Blood chemistry and BT results indicated an effective ISS in pigs (P < 0.03). Threonine intake increased PD in a linear fashion in both ISS groups (P < 0.01). The marginal efficiency of standardized ileal digestible (SID) Thr utilization for PD, represented by the slope, was not affected by ISS. However, ISS substantially increased the extrapolated maintenance SID Thr requirements, represented by the intercept at zero PD (ISSâ ' vs. ISS+, â '11.2 vs. â '56.3 SE 13.2; P < 0.05). Collectively, our results indicated that the physiological changes associated with ISS increased the dietary SID Thr requirements for PD due to an increase in maintenance requirements.
AB - Previous studies have reported an increase in the utilization of threonine (Thr) during immune system stimulation (ISS). However, increased utilization of an AA during ISS may not reflect an increased dietary requirement, as endogenous sources may supply AA to meet the need for enhanced utilization. The current study evaluated the impact of ISS on components of dietary Thr requirements, i.e., maintenance requirement and the efficiency of Thr utilization. Thirty-nine gilts (initial BW 32 ± 2.1 kg) of commercially relevant genetics were individually housed in metabolism crates and fed one of six experimental diets in which Thr was the first limiting among other AA. Three levels of dietary Thr were tested within each ISS group: 70%, 90%, and 110% of daily Thr requirements, which were estimated based on the potential of each ISS group for protein deposition (PD). Following adaptation to the experimental diets, pigs from each dietary treatment group were injected with either increasing amounts of Escherichia coli lipopolysaccharide (ISS+; 25 and 35 μg/kg BW) or saline (ISSâ '). Injections were given 48-h apart and whole-body nitrogen balance was measured for 72-h following the first injection. Body temperature (BT) was monitored and blood samples were collected 24 h after initiation of ISS and evaluated for measures of blood chemistry. Blood chemistry and BT results indicated an effective ISS in pigs (P < 0.03). Threonine intake increased PD in a linear fashion in both ISS groups (P < 0.01). The marginal efficiency of standardized ileal digestible (SID) Thr utilization for PD, represented by the slope, was not affected by ISS. However, ISS substantially increased the extrapolated maintenance SID Thr requirements, represented by the intercept at zero PD (ISSâ ' vs. ISS+, â '11.2 vs. â '56.3 SE 13.2; P < 0.05). Collectively, our results indicated that the physiological changes associated with ISS increased the dietary SID Thr requirements for PD due to an increase in maintenance requirements.
KW - growing pigs
KW - immune system stimulation
KW - threonine requirement
UR - http://www.scopus.com/inward/record.url?scp=85061045955&partnerID=8YFLogxK
U2 - 10.1093/jas/sky468
DO - 10.1093/jas/sky468
M3 - Article
C2 - 30541080
AN - SCOPUS:85061045955
SN - 0021-8812
VL - 97
SP - 735
EP - 744
JO - Journal of Animal Science
JF - Journal of Animal Science
IS - 2
ER -