Sunflower expellers have greater ileal digestibility of amino acids than sunflower meal, but there are only minor variations among different sources of sunflower meal when fed to growing pigs.

The objective was to test the hypothesis that there is no effect of origin or processing procedure on the standardized ileal digestibility (SID) of amino acids (AA) and crude protein (CP) in sunflower coproducts. Six sources of sunflower meal (SFM) and one source of sunflower expellers (SFE) were obtained from Ukraine, Italy, Hungary, and the United States. Each source of SFM or SFE was the only source of CP and AA in one diet, and an N-free diet was also used for a total of eight diets. Eight barrows (body weight: 28.5 ± 2.4 kg) had a T-cannula installed in the distal ileum and were allotted to one of the eight diets using an 8 × 8 Latin square design with eight periods. The Lys:CP ratio in the six sources of SFM ranged from 3.10% to 3.96% with CP concentrations ranging from 27.34% to 36.75%. CP in SFE was 26.87% and the Lys:CP ratio was 3.51%. Concentrations of acid-hydrolyzed ether extract in the six sources of SFM ranged from 0.60% to 3.11%, but SFE contained 8.77%. Results indicated that the SID of CP was lower (P < 0.05) in SFM from Hungary compared with all other sources of SFM except for one of the sources from Ukraine. There were no differences in the SID of Lys, Met, and Trp among sources of SFM, but for most of the remaining indispensable AA, the SFM from Hungary had less (P < 0.05) SID than the other sources. However, only a few differences in the SID of indispensable AA were observed among the other sources of SFM, but the SID of CP and all AA except Trp was greater (P < 0.05) in SFE compared with SFM. In conclusion, there were only a few differences in the SID of the first-limiting AA among SFM obtained from Ukraine, Hungary, Italy, and the United States, but the SID of CP and AA was greater in SFE than in SFM indicating that processing of sunflower seeds influence the nutritional value.