Premium
Potential for protein deposition and threonine requirement of modern genotype barrows fed graded levels of protein with threonine as the limiting amino acid
Author(s) -
Thong H. T.,
Liebert F.
Publication year - 2004
Publication title -
journal of animal physiology and animal nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.651
H-Index - 56
eISSN - 1439-0396
pISSN - 0931-2439
DOI - 10.1111/j.1439-0396.2004.00457.x
Subject(s) - threonine , limiting , amino acid , genotype , zoology , dietary protein , deposition (geology) , essential amino acid , protein requirement , glycine , body weight , biology , chemistry , biochemistry , food science , endocrinology , serine , gene , enzyme , mechanical engineering , paleontology , sediment , engineering
Summary The study was conducted to estimate the actual genetic potential for daily protein deposition of growing barrows [genotype: Piétrain × (Duroc × Landrace)]. Twenty‐four pigs with an average initial body weight (BW) of 43.7 ± 0.7 kg were used in a N‐balance study. Semi‐purified diets with graded levels of crude protein (45.8, 94.2, 148.0, 198.9, 255.5 and 300.2 g/kg DM) were used, based on a constant mixture of wheat, soya bean protein concentrate and potato protein concentrate as protein sources. The amino acid pattern of the diets was according to the ideal amino acid ratio for growing pigs ( Wang and Fuller , 1989), with the exception of threonine (adjusted as limiting amino acid). N‐balance data were used to estimate daily N‐maintenance requirement (NMR = 446 mg N/BW/day) by regression method and the theoretical maximum of daily N‐retention (PD max T = 3115 mg N/BW/day) based on N‐utilization model of Gebhardt (1966) using program Mathematica 3.0. The results indicate that PD max T of pigs under study is much higher than results from earlier studies with older genotypes. In summary, pigs of modern genotype have a very high genetic potential for daily protein deposition and these actual data are important basic informations for estimation of amino acid requirement within the model used. Threonine requirement data depending on threonine efficieny and protein deposition (8.96, 10.45 and 12.22 g/day for 130, 145 and 160 g daily protein deposition; 50 kg body weight) are discussed.