01 / WHY VITAMIN E
An antioxidant shrimp cannot make themselves
Vitamin E is a fat-soluble antioxidant that protects cell membranes from free radicals. Shrimp cannot make it, so it must come from feed. High stocking densities and swings in temperature and water quality expose shrimp to oxidative stress, so the authors set out to re-establish how much vitamin E whiteleg shrimp need to grow well and stay healthy.
Earlier studies in crustaceans put the optimum at about 70–100 mg/kg of feed: 80 mg/kg for black tiger shrimp, 80 mg/kg for the oriental river prawn Macrobrachium nipponense and 99 mg/kg for whiteleg shrimp (He and Lawrence, 1993).
02 / THE TRIAL
Eight vitamin E levels, 56 days, 0.2 g shrimp
- Shrimp: 0.20 g whiteleg shrimp, 30 per 180-litre tank, four tanks per group; 30 °C, 31.5‰ salinity.
- Feed: 34.8% crude protein, 8.7% lipid; protein mainly from soybean meal (40%), plus fishmeal, tuna by-product meal and squid liver meal (5% each).
- Vitamin E: DL-α-tocopherol acetate at eight levels, 0–240 mg/kg. Measured in the feed: 14.4, 26.2, 47.4, 59.9, 82.9, 99.3, 134.8 and 260.4 mg/kg (the “zero” diet still had 14 mg/kg from its ingredients).
- Feeding: six meals a day at 5–12% of body weight for 56 days.
03 / GROWTH
60–80 mg/kg: shrimp about one third heavier
Shrimp on the unsupplemented feed reached 3.80 g. Those on 60 mg/kg reached 5.03 g and those on 80 mg/kg reached 5.13 g, the highest in the trial; weight gain rose from 1,800% to 2,451%. Above 80 mg/kg growth did not improve further but declined: 4.83 g at 100 mg/kg and 4.21 g at 240 mg/kg.
Broken-line regression put the optimum at 72.2 mg/kg for weight gain. Survival during the feeding trial was high in every group (92.5–100%), and feed conversion (1.32–1.45) did not differ significantly.
Optimum dietary vitamin E for weight gain in young whiteleg shrimp, by the authors’ broken-line regression.
Final weight at 80 mg/kg (5.13 g) compared with no supplementation (3.80 g) after 56 days.
Shrimp with enough vitamin E also digested their feed better: protein digestibility rose from 85.1% to 90.9% and dry-matter digestibility from 71.9% to 82.7% at 80 mg/kg. Intestinal villi were taller: 23.7 µm without supplementation, 29.4 µm at 80 mg/kg.
04 / DISEASE RESISTANCE
AHPND challenge: 73% survival versus 29%
After the 56-day trial, 45 shrimp per group were split across three 120-litre tanks, and 50 ml of Vibrio parahaemolyticus culture of a strain causing acute hepatopancreatic necrosis disease (AHPND), at 2.8 million cells/ml, was added to each tank’s water. Signs of disease appeared from hour 6. After 10 days:
- No supplement and 20 mg/kg: 28.9–30% survived.
- 40 and 60 mg/kg: 46.7% and 66.7%.
- 80, 100 and 120 mg/kg: 73.3%, clearly higher than without supplementation.
- 240 mg/kg: 63.3%.
Immune indicators moved the same way: lysozyme activity rose from 3.55 to 4.97 µg/ml and antiprotease activity from 4.5% to 14.4% at 80 mg/kg. The authors say adequate vitamin E “may help reduce” the incidence of AHPND — a tank challenge result, not a cure.
05 / TOO LITTLE, TOO MUCH
Above 120 mg/kg, oxidative markers rise again
Vitamin E stored in the hepatopancreas rose with the dose: 5 µg/g without supplementation, 227 µg/g at 80 mg/kg and 623 µg/g at 240 mg/kg. But MDA — a product of lipid oxidation and a sign of cell damage — was lowest at 80 mg/kg (1.11) and rose to 3.90 at both 120 and 240 mg/kg, above even the unsupplemented group (2.41).
“High doses of vitamin E may be toxic: slowing growth, raising MDA and lowering immunity.”
Ko et al., PLoS ONE 2025 · Paraphrased
In other words, vitamin E has a useful range: below about 60 mg/kg shrimp do not reach their growth potential, and above about 120 mg/kg there is no further gain and some harm.
06 / THAN VUONG’S VIEW
What should farmers know?
- 72 mg/kg is the total in the feed, including what is already there. Commercial feeds usually contain vitamin E; before adding more, check the label or ask the feed maker for the current level.
- More is not better: in the trial, 240 mg/kg gave slower growth than 80 mg/kg.
- Vitamin E is lost when feed goes rancid: store feed in a dry, cool, shaded place and use it before its expiry date — oxidising oil in the feed uses up vitamin E.
- These are tank results with small shrimp over 56 days; the authors note that pond conditions and other life stages may differ.
Also in this series: arginine for whiteleg shrimp post-larvae; lysine for GIFT tilapia.
QUICK ANSWERS
Frequently asked questions about vitamin E for whiteleg shrimp
How much vitamin E do whiteleg shrimp need in feed?
In the trial by Ko and colleagues (PLoS ONE 2025) with 0.2 g whiteleg shrimp over 56 days, the optimum for weight gain was about 72 mg of vitamin E per kg of feed (as DL-α-tocopherol acetate). This is the total in the feed, including what the ingredients already supply.
How much faster do shrimp grow with vitamin E?
Shrimp on the unsupplemented feed (14 mg/kg) reached 3.80 g; at 60–80 mg/kg they reached 5.03–5.13 g, about one third heavier. Feed conversion ratio did not differ significantly between groups.
Is more vitamin E always better?
No. At 240 mg/kg shrimp reached only 4.21 g, less than at 80 mg/kg, and MDA, a marker of oxidative damage, rose to 3.90 at 120 and 240 mg/kg, above the unsupplemented group (2.41).
Does vitamin E protect shrimp against AHPND?
After a challenge with Vibrio parahaemolyticus causing acute hepatopancreatic necrosis disease (AHPND), 10-day survival was 28.9% without supplementation and 73.3% at 80–120 mg/kg. This was a tank trial; the authors say adequate vitamin E "may help reduce" the disease, not that it cures it.
