Those are different dosage amounts, 1 400iu is a typical vitamin E capsule. 25mcg would be about 1000iu which would be more powerful in it’s effect.
Do you have a scale to weigh the gosling?
You can get vitamin E separately which would be much more effective than rooster booster poultry...
Torticolis is commonly caused by a thiamine deficiency or a vitamin E deficiency.
Usually if one deficiency is present there are multiple vitamin and nutrient deficiencies however.
Definitely follow @Jenbirdee ’s advice and get the vitamin B complex but ALSO get a liquid multivitamin that...