Natural or synthetic vitamin E for mink kits

Transcription

1 Natural or synthetic vitamin E for mink kits Søren Krogh Jensen, Department of Animal Science, Aarhus University Tove N. Clausen & Peter Foged Larsen Kopenhagen Fur

2 Why Vitamin E? Mink are fed high amounts of poly unsaturated fatty acids Mink feed ingredients may have been challenged by different microorganisms Mink feed contain high amount of prooxidative cations (Fe and Cu) Mink feed may contain high amount of reactive oxygen species

3 Why Vitamin E? Antioxidant in cell membranes Protect double bonds in unsaturated fatty acids Have immuno modulation properties

4 Relationship between content of unsaturated fatty acids (iodine value) and vitamin E status in mink Iodine value y = 1.5x 2-34x R 2 =, Tocopherol, µg/ml plasma

5 Three commercial forms of vitamin E RRR Natural All-rac Synthetic Alcohol High activity Unstable, expensive Acetate High activity Stable, expensive Low activity Stable, cheap

6 Hydrolysis of -tocopherol acetate in the small intestine O H 2 O O Pancreatic Esterase O CH 3 COO - H O

7 -Tocopherol transport protein Liver is main discrimination site

8 -Tocopherol: alcohol versus acetate Alcohol: Natural unstable Synthetic: Acetate stable

9 When two compounds are stereoisomers they differ in the same way as right hand differs from left hand

10 Biological activity of the 8 stereoisomers of all-rac- tocopherol determined by the rat resorption gestation test Natural vitamin E

11 Biological activity of the 8 stereoisomers of all-rac- tocopherol determined by the rat resorption gestation test Natural vitamin E

12 Vitamin E and mink kits Mink are born without measureable vitamin E in the body Vitamin E from milk are well absorbed Mink milk can be enriched through the mothers feed

13 Feeding experiment 168 mink kits 4 week of age Experimental period 6 week 3 types of vitamin E RRR-OH (Natural alcohol) RRR-Ac (Natural acetate) All-rac-Ac (Synthetic acetate) Control group ( mg vit E) 4 dosage levels (5, 75, 1, 15 mg/kg feed

14 Sampling Feed analysed 12 kits euthanized at experimental starts 6 kits from each group after 3 wk in exp. 6 kits from each group after 6 wk in exp. Mink and organs weighed Plasma and liver analysed for tocopherols and -tocopherol stereoisomers

15 Results plasma -Tocopherol in mink plasma µg/ml Age, week

16 Results plasma -Tocopherol in mink plasma µg/ml all-rac-α-toc-ac Age, week

17 Results plasma -Tocopherol in mink plasma all-rac-α-toc-ac µg/ml all-rac-α-toc-ac all-rac-α-toc-ac Age, week 15 all-rac-α-toc-ac

18 Results plasma -Tocopherol in mink plasma 3 µg/ml RRR-α-toc-Ac 75 RRR-α-toc-Ac 1 RRR-α-toc-Ac 15 RRR-α-toc-Ac 5 all-rac-α-toc-ac 75 all-rac-α-toc-ac 1 all-rac-α-toc-ac Age, week 15 all-rac-α-toc-ac

19 Results plasma -Tocopherol in mink plasma µg/ml Age, week 5 RRR-α-toc 75 RRR-α-toc 1 RRR-α-toc 15 RRR-α-toc 5 RRR-α-toc-Ac 75 RRR-α-toc-Ac 1 RRR-α-toc-Ac 15 RRR-α-toc-Ac 5 all-rac-α-toc-ac 75 all-rac-α-toc-ac 1 all-rac-α-toc-ac 15 all-rac-α-toc-ac

20 -Tocopherol in plasma after 6 weeks of vitamin supplementation Dose vs source 3 25 y = -,5x2 +,225x + 5,18 R² =,996 y = -,7x2 +,227x + 5,7 R² =,986 µg/ml plasma y = -,1x2 +,12x + 5,46 R² =,999 Nat Alc Nat Ac Syn Ac Alfa-tokoferol, mg/kg feed

21 Results liver µg -tocopherol/g liver Age, week 5 RRR-α-toc 75 RRR-α-toc 1 RRR-α-toc 15 RRR-α-toc 5 RRR-α-toc-Ac 75 RRR-α-toc-Ac 1 RRR-α-toc-Ac 15 RRR-α-toc-Ac 5 all-rac-α-toc-ac 75 all-rac-α-toc-ac 1 all-rac-α-toc-ac 15 all-rac-α-toc-ac

22 Results liver 5 µg -tocopherol/g liver all-rac-α-toc-ac Age, week

23 Results liver 5 µg -tocopherol/g liver all-rac-α-toc-ac 2 75 all-rac-α-toc-ac 1 1 all-rac-α-toc-ac Age, week 15 all-rac-α-toc-ac

24 Results liver µg -tocopherol/g liver Age, week 5 RRR-α-toc-Ac 75 RRR-α-toc-Ac 1 RRR-α-toc-Ac 15 RRR-α-toc-Ac 5 all-rac-α-toc-ac 75 all-rac-α-toc-ac 1 all-rac-α-toc-ac 15 all-rac-α-toc-ac

25 Results liver µg -tocopherol/g liver Age, week 5 RRR-α-toc 75 RRR-α-toc 1 RRR-α-toc 15 RRR-α-toc 5 RRR-α-toc-Ac 75 RRR-α-toc-Ac 1 RRR-α-toc-Ac 15 RRR-α-toc-Ac 5 all-rac-α-toc-ac 75 all-rac-α-toc-ac 1 all-rac-α-toc-ac 15 all-rac-α-toc-ac

26 Total -tocopherol content in liver, µg/g liver after 6 wk supplementation Tocopherol, µg/g liver y =,19x + 4,6 R² =,98 y =,2x + 3,32 R² =,97 y =,2x + 3,79 R² =,97 RRR-OH RRR-Ac All-rac-AC Tocopherol, mg/kg feed

27 2S and RRR- -tocopherol in liver µg/g liver after 6 wk supplementation -Tocopherol µg/g liver S RRR 2S RRR 2S RRR 75 -tocopherol mg/kg feed RRR-OH RRR-Ac All-rac-AC

28 Conclusions RRR- -tocopherol is taken up in the blood stream at the highest rate and maintained in the highest concentration The liver is the major site for biological discrimination of non-natural stereoisomers At low concentration in the feed natural acetate is utilized as good as the natural alcohol At high concentration the alcohol form is superior to the acetate form.