Ileal endogenous loss and standardized ileal digestibility of amino acids in rye genotypes for pigs

The present study aimed to determine basal ileal endogenous loss (IAA(end)) of CP and AA and standardized ileal digestibility (SID) of CP and AA in rye for pigs. Eight rye genotypes (9.5 to 11.2% CP, as-fed basis) were fed as the sole dietary CP source to 8 ileal cannulated barrows (24 +/- 2 kg initial BW) according to an 8 x 8 Latin square design. The IAA(end) and SID were determined by linear regression analysis between dietary contents of apparent ileal digestible (AID) and total AA. Linear relationships (P <= 0.05) between dietary contents of AID and total AA could be established. The IAA(end) and SID of CP and AA (%) in rye were as follows: 26.9 g/kg DMI and 84% of CP, 1.5 g/kg DMI and 93% of Arg, 0.6 g/kg DMI and 91% of His, 1.0 g/kg DMI and 90% of Ile, 0.9 g/kg DMI and 79% of Leu, 0.8 g/kg DMI and 70% of Lys, 0.3 g/kg DMI and 83% of Met, 1.3 g/kg DMI and 90% of Phe, 0.8 g/kg DMI and 70% of Thr, 0.2 g/kg DMI and 66% of Trp, and 0.6 g/kg DMI and 76% of Val, respectively. Use of the regression analysis method in the present study with different rye genotypes showed greater IAA(end) in pigs fed cereal-based diets compared with reports using alternative methods including N-free feeding. As a result, SID of AA in rye was higher in comparison with tabulated values.