Lysine:Energy Ratio Conversion

When determining the proper ratio of digestible lysine (Dig Lys) to digestible energy (DE) one must consider factors such as genetics, environment, and market premiums. Research studies have indicated that a Dig Lys:DE ratio falling between .50 and .70 is most effective. The higher the Dig Lys:DE ratio, the greater feed efficiency will become (i.e. more efficient), and typically the leaner the pig will be. However, as both the total energy and Dig Lys:DE ratio increase, diet cost and total cost of production rapidly increase. Producers should look at energy costs and adjust the ratio accordingly.

Matrix represents the lysine content of diet based on lysine:energy ratios
Lysine:Digestible Energy Ratio ME, kcal/lb 1625 1600 1575 1550 1525 1500
DE, kcal/lb 1,693 1,667 1,641 1,615 1,589 1,563
MJ/kg 15.62 15.38 15.14 14.90 14.66 14.42
g/mJ g/Mcal
0.900 2.548 1.406 1.384 1.362 1.341 1.319 1.298
0.875 2.621 1.367 1.346 1.325 1.304 1.283 1.262
0.850 2.698 1.328 1.307 1.287 1.266 1.246 1.226
0.825 2.780 1.289 1.269 1.249 1.229 1.209 1.189
0.800 2.867 1.250 1.230 1.211 1.192 1.173 1.153
0.775 2.960 1.210 1.192 1.173 1.155 1.136 1.117
0.750 3.058 1.171 1.153 1.135 1.117 1.099 1.081
0.725 3.164 1.132 1.115 1.098 1.080 1.063 1.045
0.700 3.277 1.093 1.077 1.060 1.043 1.026 1.009
0.675 3.398 1.054 1.038 1.022 1.006 0.989 0.973
0.650 3.529 1.015 1.000 0.984 0.968 0.953 0.937
0.625 3.670 0.976 0.961 0.946 0.931 0.916 0.901
0.600 3.823 0.937 0.923 0.908 0.894 0.879 0.865
0.575 3.989 0.898 0.884 0.870 0.857 0.843 0.829
0.550 4.170 0.859 0.846 0.833 0.819 0.806 0.793
0.525 4.369 0.820 0.807 0.795 0.782 0.770 0.757
0.500 4.587 0.781 0.769 0.757 0.745 0.733 0.721
0.475 4.829 0.742 0.730 0.719 0.708 0.696 0.685
0.450 5.097 0.703 0.692 0.681 0.670 0.660 0.649
0.425 5.397 0.664 0.654 0.643 0.633 0.623 0.613
0.400 5.734 0.625 0.615 0.606 0.596 0.586 0.577
0.375 6.116 0.586 0.577 0.568 0.559 0.550 0.541
0.350 6.553 0.547 0.538 0.530 0.521 0.513 0.505
0.325 7.057 0.508 0.500 0.492 0.484 0.476 0.469
0.300 7.645 0.469 0.461 0.454 0.447 0.440 0.433
0.275 8.340 0.430 0.423 0.416 0.410 0.403 0.396
0.250 9.175 0.390 0.384 0.378 0.372 0.366 0.360
0.225 10.194 0.351 0.346 0.341 0.335 0.330 0.324
0.200 11.468 0.312 0.308 0.303 0.298 0.293 0.288
0.175 13.106 0.273 0.269 0.265 0.261 0.257 0.252

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