P. Bikker et al., AMINO-ACID-COMPOSITION OF GROWING PIGS IS AFFECTED BY PROTEIN AND ENERGY-INTAKE, The Journal of nutrition, 124(10), 1994, pp. 1961-1969
Ninety-five female pigs from 20 to 45 kg body weight were used to eluc
idate the effects of energy and protein intake on the amino acid compo
sition of the protein in the carcass, organs and empty body of growing
pigs. In a 2 x 15 factorial arrangement, protein intake ranged from 1
27 to 350 g/d in 15 graduated steps; and the digestible energy allowan
ces were 15.8 and 18.8 MJ/d. Whole-body amino acid contents (g/16 g ni
trogen) were (means +/- SEM) lysine 6.64 +/- 0.028, methionine 2.11 +/
- 0.012; threonine 3.62 +/- 0.016 and total essential amino acids 42.8
+/- 0.16. The organ fraction contained 14.8 and 15.8% (SEM 0.13) of w
hole-body protein at the low and high energy levels, respectively. The
concentrations of essential amino acids were 41.8 +/- 0.19 and 48.4 /- 0.13 g/16 g nitrogen in the carcass and organs, respectively. Conce
ntrations of a number of amino acids (in carcass, organ and whole-body
protein and in protein deposited between 20 and 45 kg, were affected
by protein and/or energy intake. The amino acid pattern of the newly d
eposited protein was slightly different from that of the empty body pr
otein. The changes in amino acid contents were presumably the result o
f effects of protein and energy intake on the proportions of muscle an
d non-muscle carcass tissues and on relative weights of blood and visc
era. Consequences of these changes for the amino acid requirements are
discussed.