Needle size for Tylan 50

[Northwood Silkies]

I have two different needle sizes ... 25G and a 30G Insulin needle. Which would be better to use with Tylan 50 as I know it's kinda thick stuff. I'm planning on doing the injection under the skin in the neck/between shoulder blades area.
And is 1/4cc correct dosage for bantam size birds?
Thanks

 

[scratch'n'peck]

I think the major reason to use a smaller needle is because it hurts a little less, but every time we have given one of our chickens an injection they barely flinched due to the needle prick. I guess i would go with the larger size needle since Tylan 50 is thick. I can't recall the dosage, but I think the bottle has dosage by animal weight listed on the label.