TY - JOUR
T1 - Dietary crude protein intake influences rates of whole-body protein synthesis in weanling horses
AU - Tanner, S. L.
AU - Wagner, A. L.
AU - Digianantonio, R. N.
AU - Harris, P. A.
AU - Sylvester, J. T.
AU - Urschel, K. L.
N1 - Publisher Copyright:
© 2014 Elsevier Ltd.
PY - 2014/11/1
Y1 - 2014/11/1
N2 - The objective of this study was to measure whole-body protein kinetics in weanling horses receiving forage and one of two different concentrates: (1) commercial crude protein (CCP) concentrate, which with the forage provided 4.1 g CP/kg bodyweight (BW)/day (189 mg lysine (Lys)/kg BW/day), and (2) recommended crude protein (RCP) concentrate which, with the same forage, provided 3.1 g CP/kg BW/day (194 mg Lys/kg BW/day). Blood samples were taken to determine the response of plasma amino acid concentrations to half the daily concentrate allocation. The next day, a 2 h-primed, constant infusion of [13C]sodium bicarbonate and a 4 h-primed, constant infusion of [1-13C]phenylalanine were used with breath and blood sampling to measure breath 13CO2 and blood [13C]phenylalanine enrichment. Horses on the CCP diet showed an increase from baseline in plasma isoleucine, leucine, lysine, threonine, valine, alanine, arginine, asparagine, glutamine, ornithine, proline, serine, and tyrosine at 120 min post-feeding. Baseline plasma amino acid concentrations were greater with the CCP diet for histidine, isoleucine, leucine, threonine, valine, asparagine, proline, and serine. Phenylalanine, lysine, and methionine were greater in the plasma of horses receiving the RCP treatment at 0 and 120 min. Phenylalanine intake was standardized between groups; however, horses receiving the RCP diet had greater rates of phenylalanine oxidation (P = 0.02) and lower rates of non-oxidative phenylalanine disposal (P = 0.04). Lower whole-body protein synthesis indicates a limiting amino acid in the RCP diet.
AB - The objective of this study was to measure whole-body protein kinetics in weanling horses receiving forage and one of two different concentrates: (1) commercial crude protein (CCP) concentrate, which with the forage provided 4.1 g CP/kg bodyweight (BW)/day (189 mg lysine (Lys)/kg BW/day), and (2) recommended crude protein (RCP) concentrate which, with the same forage, provided 3.1 g CP/kg BW/day (194 mg Lys/kg BW/day). Blood samples were taken to determine the response of plasma amino acid concentrations to half the daily concentrate allocation. The next day, a 2 h-primed, constant infusion of [13C]sodium bicarbonate and a 4 h-primed, constant infusion of [1-13C]phenylalanine were used with breath and blood sampling to measure breath 13CO2 and blood [13C]phenylalanine enrichment. Horses on the CCP diet showed an increase from baseline in plasma isoleucine, leucine, lysine, threonine, valine, alanine, arginine, asparagine, glutamine, ornithine, proline, serine, and tyrosine at 120 min post-feeding. Baseline plasma amino acid concentrations were greater with the CCP diet for histidine, isoleucine, leucine, threonine, valine, asparagine, proline, and serine. Phenylalanine, lysine, and methionine were greater in the plasma of horses receiving the RCP treatment at 0 and 120 min. Phenylalanine intake was standardized between groups; however, horses receiving the RCP diet had greater rates of phenylalanine oxidation (P = 0.02) and lower rates of non-oxidative phenylalanine disposal (P = 0.04). Lower whole-body protein synthesis indicates a limiting amino acid in the RCP diet.
KW - Amino acids
KW - Horse
KW - Phenylalanine kinetics
KW - Protein intake
KW - Protein synthesis
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U2 - 10.1016/j.tvjl.2014.06.002
DO - 10.1016/j.tvjl.2014.06.002
M3 - Article
C2 - 24973006
AN - SCOPUS:84919462678
SN - 1090-0233
VL - 202
SP - 236
EP - 243
JO - Veterinary Journal
JF - Veterinary Journal
IS - 2
ER -