Figure 5. Incorporation of 14 Figure 4. Oxidation of 14 C labelled DL-Met, L-Met and HMB (adapted
from Saunderson, 1985). Interestingly, sum of excretion, oxidation and water content of
DL-HMTBA would reduce the bioavailability of DL-HMTBA to 62 % (Formula 1).
Formula 1 (DL-HMTBA): 100 - (21 + 5 + 12) = 62 %
For DL-Methionine, sum of excretion and oxidation would reduce the bioavailability of DL-Met to 85 % (Formula 2).
Formula 2 (DL-Met): 100 - (10 + 5.5) = 84.5 % L-Met metabolism is the standard and the natural metabolic
process. L-Met was also excreted (1.8 %) and oxidized (4.2 %). Consequently, we must consider additionally the L-Met metabolism (excretion and oxidation) of 6 %, leading to 90.5 % and 67 % as conservative bioavailability values for DL-Met and DL-HMTBA compared with L-Met without considering methionine efficacy for protein
Conclusion In conclusion, DL-HMTBA and DL-Met could be easily replaced with 67 % and 90.5 % L-Met without compromising performance of animals.
For references contact the author (
b.saremi@
cj.net)
C labelled L-met, DL-met and HMB into tissue proteins (adapted from Saunderson, 1985).
synthesis in muscle tissues or other organs. A higher deposition of L-Met in breast muscle and in the legs (Fig 5) were observed compared with DL-Met and DL-HMTBA (Saunderson, 1985 and 1987). Similar results were reproducible under methionine deficiency
and under feed restriction (Saunderson, 1987) proving independence of the excretion of the methionine sources from the level of feeding or levels of sulfur amino acids in feed (Saunderson, 1987). Oxidation was affected by feed restriction and by methionine deficiency (Saunderson, 1987). DL-Met oxidation increased to 10 % of the given dose under limited feeding condition. In general, DL-Met had the highest oxidation rate among the methionine sources.
FEED COMPOUNDER MARCH/APRIL 2019 PAGE 37
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60
