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Effects of increasing crystalline amino acids in sorghum- or corn-based diets on nursery pig growth performance
A total of 300 pigs (PIC 1050; initially 10.6 kg BW) were used in a 21-d study to compare the effects of increasing crystalline AA in sorghum- and corn-based diets on nursery pig growth performance. Treatments with 5 pigs per pen and 10 pens per treatment were arranged in a 2 × 3 factorial with main effects of grain source (sorghum vs. corn) and crystalline AA supplementation (low, medium, or high). Because replacing increasing amounts of soybean meal with crystalline AA changes the NE of the diet, all diets were formulated 5.04 g SID Lys:Mcal NE. The Lys concentration in the diets was formulated at 95% of the pig’s estimated requirement to ensure that the other AA, on a ratio relative to Lys, would not be underestimated. Amino acid ratios to Lys and standardized ileal digestibility (SID) coefficients used were obtained from NRC (2012). The grain sources and soybean meal were analyzed for AA profile and diets formulated from these concentrations. Sorghum AA concentrations were 0.17% Lys, 0.13% Met, 0.23% Thr, 0.08% Trp, and 0.33% Val. Corn analyzed at 0.23% Lys, 0.17% Met, 0.28% Thr, 0.06% Trp, and 0.36% Val. Soybean Meal analyzed at 2.86% Lys, 0.65% Met, 1.82% Thr, 0.68% Trp, and 2.13% Val. The low AA fortification contained L-lysine HCl and DL-methionine. The medium AA fortification contained L-lysine HCl, DL-methionine, and L-threonine, and the high AA fortification contained L-lysine HCl, DL-methionine, L-threonine, and L-valine. Overall, there were no main or interactive effects (P > 0.05) of grain source or AA supplementation rate detected for ADG, ADFI, or G:F. This suggests that balancing to the third, fourth, or fifth limiting AA is possible in both sorghum- and corn-based diets with the use of crystalline AA without detrimental effects on growth performance. Results also suggest that corn and sorghum elicit similar nursery pig performance when serving as the only grain source in the diet.
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Grain source |
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Sorghum |
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Corn |
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Crystalline AA: |
Low |
Medium |
High |
|
Low |
Medium |
High |
d 0 to 21 |
|
|
|
|
|
|
|
ADG1, g |
486 |
473 |
469 |
|
473 |
479 |
478 |
ADFI1, g |
745 |
722 |
740 |
|
729 |
729 |
739 |
G:F1 |
0.658 |
0.660 |
0.638 |
|
0.654 |
0.664 |
0.651 |
1SEM was 19.8, 33.8, and 0.01 for ADG, ADFI, and G:F, respectively. |
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Keywords: corn, nursery pig, sorghum