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Abstract: An experiment was conducted to measure the digestibility of crude protein (CP) and amino acids (AA) by weanling pigs in full-fat soybeans (FFSB) produced from conventional (FFSB-CV), high-protein (FFSB-HP), or low-oligosaccharide (FFSB-LO) varieties of soybeans. A source of soybean meal (SBM) that was produced from a conventional variety of soybeans was also used in the experiment. Cornstarch-based diets containing FFSB-CV, FFSB-HP, FFSB-LO, or SBM as the sole source of AA were formulated. A nitrogen-free diet was used to determine basal ileal endogenous losses of AA. The coefficient of ileal standardized digestibility (CISD) of AA in the four ingredients was measured using 10 barrows (initial body weight: 10.1±1.82kg) that were equipped with a T-cannula in the distal ileum. The CISD of leucine, lysine, and phenylalanine in FFSB-CV was greater (P<0.05) than in SBM, but the CISD of AA in FFSB-HP and FFSB-LO were not different (P>0.05) from the CISD of AA in SBM. With the exception of methionine, tryptophan, and cysteine, no differences in CISD of AA among the three sources of FFSB were observed (P>0.05). It is concluded that the CISD of most AA in FFSB-HP and FFSB-LO are not different from the CISD of AA in FFSB-CV or in SBM, but FFSB-CV has a greater CISD of leucine, lysine, and phenylalanine than SBM if fed to weanling pigs. [ABSTRACT FROM AUTHOR]

One of the goals of swine diet formulation is minimizing nitrogen (N) excretion as well as maximizing N retention. This study was conducted to test the hypothesis that different requirement expressions of dietary amino acids (AA) may affect N balance in pigs. Twelve pigs with average body weight of 40.9 kg (standard deviation =3.3) were used in a quadruplicated 3×3 Latin square design. Three diets were formulated to meet AA requirement estimates based on total AA (Diet total ), apparent ileal digestible AA (Diet AID ), or standardized ileal digestible AA (Diet SID ) with constant amounts of corn, soybean meal, and corn germ meal but different crystalline AA contents. Total feces and urine were collected. Nitrogen balance was calculated based on the analyzed data of the diets, feces, and urine samples. Preplanned orthogonal contrasts were used to compare the least squares means among treatments: 1) Diet total vs. Diet AID and Diet SID and 2) Diet AID vs. Diet SID . Pigs fed Diet total had less retained N ( P =0.048) and retention coefficients ( P <0.01) resulting in greater urinary ( P =0.014) and total ( P =0.017) N excretion than Diet AID and Diet SID . Urinary N excretion tended to be greater ( P =0.074) for pigs fed Diet AID than Diet SID . In conclusion, formulating swine diets based on digestible AA rather than on total AA can reduce N excretion. [ABSTRACT FROM AUTHOR]

This experiment was conducted to investigate the effects of deoxynivalenol (DON) and zearalenone (ZON) on the apparent ileal digestibility (AID) of AA in growing pigs. Twelve pigs (initial mean body weight = 20.6 ± 2.1 kg) cannulated at the distal ileum were assigned to 3 dietary treatments in a quadruplicated 3 × 2 incomplete Latin square design with 3 diets and 2 periods. Three experimental diets consisted of a corn-soybean meal-based control diet, a DON-supplemented diet at 10 mg/kg and a ZON-supplemented diet at 10 mg/kg. All diets contained 5 g/kg chromic oxide as an indigestible index. Each experimental period was comprised of a 5-d adaptation period and a 3-d ileal digesta collection period. The concentration of DON or ZON in the mycotoxin-supplemented diet was analyzed to be 11.2 mg/kg or 11.6 mg/kg, respectively. Pigs fed the DON-supplemented diet had less AID of Lys (0.799 vs. 0.839, P = 0.08), Thr (0.695 vs. 0.751, P = 0.08), Trp (0.766 vs. 0.840, P = 0.02), and Val (0.687 vs. 0.749, P = 0.08) than those fed the control diet, but the AID of other AA were not affected by DON supplementation. With the exception of Trp (0.771 vs. 0.840, P = 0.04), the supplementation of ZON to the control diet did not affect the AID of AA. In conclusion, dietary DON, but not ZON, may reduce the AID of some indispensable AA. [ABSTRACT FROM AUTHOR]

This experiment was conducted to determine the coefficients of ileal apparent (CIAD) and standardized digestibility (CISD) of crude protein (CP) and amino acids (AA) in corn sources from different origins for pigs. The corn sources included yellow corn from the United States ( n = 5; USY), yellow corn from South Africa ( n = 2; SAY), and white corn from South Africa ( n = 2; SAW). Nine diets were prepared to contain each corn source at 947 g/kg as the sole source of CP and AA. A nitrogen-free diet was also prepared and used to measure basal endogenous losses of CP and AA. Ten boars with an initial body weight of 52.2 ± 9.0 kg were surgically fitted with a T-cannula in the distal ileum and were allotted to a 10×10 Latin square design with 10 diets and 10 periods. Each period consisted of 3-day adaptation and 2-day sample collection periods. Results indicated that the concentrations of CP and AA varied among corn sources from different origins, and those of lysine and tryptophan had coefficient of variation of 16.3 and 24.0%, respectively. Significant differences were observed (P<0.05) for the CIAD of CP and AA (arginine, histidine, lysine, tryptophan, aspartic acid, cysteine, glycine, and proline) among the nine corn sources. The CIAD values of most AA except for six AA (isoleucine, leucine, phenylalanine, tryptophan, proline, and tyrosine) were greater (P<0.05) for SAY than those for USY. The CISD values of CP and most AA were similar among corn sources. However, the CISD of lysine was different (P=0.017) among the nine corn sources in the range of 0.611–0.765. The CISD of lysine for SAY (0.747) was greater (P<0.001) than that for USY (0.655). In conclusion, the CIAD values of CP and most AA in corn varied among corn sources from different origins, but the CISD values of AA except lysine were relatively similar among corn sources with varying concentrations of CP and AA. Further research is required to identify the reasons for the variability in the CISD of lysine among corn sources from different origins and to search for a method to reduce variability. [ABSTRACT FROM AUTHOR]