The jugular vein can be distended by placing hand or fingers firmly against the neck.  Look for the vein filling in the area that the index finger is pointing to in the photo.

Always begin with sterile tube and needle.  One end of the double blood collection needle is inserted into the needle holder.

The person collecting the blood sample holds the needle and tube in one hand.  Do not push the tube onto the needle until the needle is in the sheep.

Firmly push the needle through the skin in the area of the jugular vein

Push tube into needle.  If you are in the vein the tube will fill.  If the tube does not fill move the needle until it does.